How Solar WorksHow do I find the best solar companies where I live? Should I buy or lease solar panels?

How to Go Solar There are several different ways you can go solar today:

1. Pay a solar company for a complete solar system and the solar installation. For most of us, this requires taking out a pretty hefty loan.

2. Contact a solar service company that will let you lease their solar panels for little or no upfront costs. Extremely convenient, but not necessarily the best option if you want the most long-term savings.

3. Buy solar panels and install them yourself. Note that proper certification is required to grid-tie the solar system.

4. Subscribe to a solar garden. An excellent option for homeowners that can`t get solar panels themselves due to shading, limited space or ownership issues.

5. Crowdfunding large-scale solar projects is also possible. Non-accredited investors can earn interest by financing clean energy projects all over the world.

 How are you supposed to figure out what`s best in your situation? How do you find the best company? The solar world sure can be confusing. Not only do you have to figure out whether to buy, lease, build, subscribe or crowdfund, but you also have to find the right company to work with: There are literally hundreds of solar installers, solar services and solar financers to choose from.We have partnered with One Block Off the Grid (1BOG) to help homeowners quickly and seamlessly through the process. So far, over 3,600 members have gone solar through 1BOG and they save on average $1217.63 a year on electricity.1BOG will help you find the best solar deal possible, and they do it for free.With an independent 1BOG solar consultant at your side, you can compare custom quotes from the biggest solar providers in the industry (including SolarCity, SunRun, One Roof Energy and Pure Energies) and quickly figure out if solar makes sense for you:

What are the components of a solar panel system and how do they actually work? Solar Cells and Solar Panels – What is the Difference?

The earth absorbs about 3,850,000 exajoules (EJ) of solar energy every year. [1] One hour would cover the world`s entire energy demand for one year.[2]The potential of solar energy is almost beyond anyone`s imagination. How can we tap into this vast resource? Let`s take a look at how solar panels work.There are mainly two main types of solar panels:

1. Photovoltaic (PV) solar panels – the technology most people think of when they say “solar panels”. These devices convert sunlight into electricity. For the sake of this article, the term “solar panels” will be used to describe photovoltaic panels.

2. Solar thermal  collectors use the same solar energy that photovoltaic panels do, but they generate heat instead of electrical power.

 What exactly is sunlight? The best way of describing light in general is probably this: A collection of tiny elementary particles called photons. These light particles carry a certain amount of energy, which can be converted into electrical energy through the photovoltaic effect in solar cells.Solar cells generate an electric current when they are exposed to light. Exactly how this happens is a quite complex, and varies between the different types of solar panels.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false)

{echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> The basic gist is this:

1. Incoming photons are absorbed by semiconducting material (in most cases silicon) on the surface of thesolar cell.

2. These photons “knock loose” electrons from atoms in the solar cell. Since electrons carry a negative charge, an electric potential difference has been created.

3. The solar cell is built in a way that only allows the electron to move in one direction in order to cancel out the potential.

4. Put many of these reactions together and current starts flowing through the material. Solar cells are building blocks of solar panels. Multiple solar cells that are oriented in the same way makes up what we call solar panels. The electrical power out depends on how many of them are put together. The solar panels you have in your calculator and those NASA use in space are essentially built using the same principles – even though they are on completely opposite sides in the strength spectrum.

Grid-Tied, Off-Grid and Hybrid Solar Systems What are the benefits of grid-connected solar panels vs. living off the grid?Deciding whether or not to grid-tie your solar panels is usually pretty straightforward – the clear-cut benefits of being grid-tied appeals to the majority of homeowners. There are, however, some people that choose to live off the grid.What would be the best in your situation? Let`s look closer at the benefits and downsides of grid-tied, off-grid and hybrid solar systems. Grid-Tied Solar SystemsGrid-tied, on-grid, utility-interactive, grid intertie and grid backfeeding are all terms used to describe the same concept – a solar system that is connected to the utility power grid.

 Advantages of Grid-Tied Systems1. Save more money with net meteringA grid-connection will allow you to save more money with solar panels through better efficiency rates, net metering, plus lower equipment and installation costs:Batteries, and other stand-alone equipment, are required for a fully functional off-grid solar system and add to costs as well as maintenance. Grid-tied solar systems are therefore generally cheaper and simpler to install.Your solar panels will often generate more electricity than what you are capable of consuming. With net metering, homeowners can put this excess electricity onto the utility grid instead of storing it themselves with batteries.Net metering (or feed-in tariff schemes in some countries) play an important role in how solar power is incentivized. Without it, residential solar systems would be much less feasible from a financial point of view.Many utility companies are committed to buying electricity from homeowners at the same rate as they sell it themselves. 2. The utility grid is a virtual batteryElectricity has to be spent in real time. However, it can be temporarily stored as other forms of energy (e.g. chemical energy in batteries). Energy storage typically comes with significant losses.The electric power grid is in many ways also a battery, without the need for maintenance or replacements, and with much better efficiency rates. In other words, more electricity (and more money) goes to waste with conventional battery systems.According to EIA data[1], national, annual electricity transmission and distribution losses average about 7% of the electricity that is transmitted in the United States. Lead-acid batteries, which are commonly used with solar panels, are only 80-90% efficient at storing energy, and their performance degrades with time.Additional perks of being grid-tied include access to backup power from the utility grid (in case your solar system stop generating electricity for one reason or another). At the same time you help to mitigate the utility company`s peak load. As a result, the efficiency of our electrical system as a whole goes up. 

Equipment for Grid-Tied Solar SystemsThere are a few key differences between the equipment needed for grid-tied, off-grid and hybrid solar systems. Standard grid-tied solar systems rely on the following components:

Grid-Tie Inverter (GTI) or Micro-Inverters Power Meter

 Grid-Tie Inverter (GTI)What is the job of a solar inverter? They regulate the voltage and current received from your solar panels. Direct current (DC) from your solar panels is converted into alternating current (AC), which is the type of current that is utilized by the majority of electrical appliances.In addition to this, grid-tie inverters, also known as grid-interactive or synchronous inverters, synchronize the phase and frequency of the current to fit the utility grid (nominally 60Hz). The output voltage is also adjusted slightly higher than the grid voltage in order for excess electricity to flow outwards to the grid. Micro-InvertersMicro-inverters go on the back of each solar panel, as opposed to one central inverter that typically takes on the entire solar array.There has recently been a lot of debate on whether micro-inverters are better than central (string) inverters.Micro-inverters are certainly more expensive, but in many cases yield higher efficiency rates. Homeowners who are suspect to shading issues should definitely look into if micro-inverters are better in their situation. Power MeterMost homeowners will need to replace their current power meter with one that is compatible with net metering. This device, often called a net meter or a two-way meter, is capable of measuring power going in both directions, from the grid to your house and vice versa.You should consult with your local utility company and see what net metering options you have. In some places, the utility company issues a power meter for free and pay full price for the electricity you generate; however, this is not always the case. Off-Grid Solar SystemsAn off-grid solar system (off-the-grid, standalone) is the obvious alternative to one that is grid-tied. For homeowners that have access to the grid, off-grid solar systems are usually out of question. Here`s why:To ensure access to electricity at all times, off-grid solar systems require battery storage and a backup generator (if you live off-the-grid). On top of this, a battery bank typically needs to be replaced after 10 years. Batteries are complicated, expensive and decrease overall system efficiency.

 Advantages of Off-Grid Solar Systems1. No access to the utility gridOff-grid solar systems can be cheaper than extending power lines in certain remote areas.Consider off-gird if you’re more than 100 yards from the grid. The costs of overhead transmission lines range from $150,000 per mile (for rural construction) to $5,000,000 per mile (for urban construction).[2]

 2. Become energy self-sufficientLiving off the grid and being self-sufficient feels good. For some people, this feeling feeling is worth more than saving money. Energy self-sufficiency is also a form of security. Power failures on the utility grid do not affect off-grid solar systems.On the flip side, batteries can only store a certain amount of energy, and during cloudy times, being connected to the grid is actually where the security is. You should install a backup generator to be prepared for these kinds of situations. Equipment for Off-Grid Solar SystemsTypical off-grid solar systems require the following extra components:

Solar Charge Controller Battery Bank DC Disconnect (additional) Off-Grid Inverter Backup Generator (optional)

 Solar Charge ControllerSolar charge controllers are also known as charge regulators or just battery regulators. The last term is probably the best to describe what this device actually does: Solar battery chargers limit the rate of current being delivered to the battery bank and protect the batteries from overcharging.Good charge controllers are crucial for keeping the batteries healthy, which ensures the lifetime of a battery bank is maximized. If you have a battery-based inverter, chances are that the charge controller is integrated. 

Battery BankWithout a battery bank (or a generator) it’ll be lights out by sunset. A battery bank is essentially a group of batteries wired together. DC Disconnect SwitchAC and DC safety disconnects are required for all solar systems. For off-grid solar systems, one additional DC disconnect is installed between the battery bank and the off-grid inverter. It is used to switch off the current flowing between these components. This is important for maintenance, troubleshooting and protection against electrical fires. Off-Grid InverterThere`s no need for an inverter if you`re only setting up solar panels for your boat, your RV, or something else that runs on DC current. You will need an inverter to convert DC to AC for all other electrical appliances.Off-grid inverters do not have to match phase with the utility sine wave as opposed to grid-tie inverters. Electrical current flows from the solar panels through the solar charge controller and the bank battery bank before it is finally converted into AC by the off-grid-inverter. Backup GeneratorIt takes a lot of money and big batteries to prepare for several consecutive days without the sun shining (or access to the grid). This is where backup generators come in.In most cases, installing a backup generator that runs on diesel is a better choice than investing in an oversized battery bank that seldom gets to operate at it`s full potential. Generators can run on propane, petroleum, gasoline and many other fuel types.Backup generators typically output AC, which can be sent through the inverter for direct use, or it can be converted into DC for battery storage. Hybrid Solar SystemsHybrid solar systems combines the best from grid-tied and off-grid solar systems. These systems can either be described as off-grid solar with utility backup power, or grid-tied solar with extra battery storage.If you own a grid-tied solar system and drive a vehicle that runs on electricity, you already kind of have a hybrid setup. The electrical vehicle is really just a battery with wheels.

 Advantages of Hybrid Solar Systems1. Less expensive than off-gird solar systemsHybrid solar systems are less expensive than off-grid solar systems. You don`t really need a backup generator, and the capacity of your battery bank can be downsized. Off-peak electricity from the utility company is cheaper than diesel. 2. Smart solar holds a lot of promiseThe introduction of hybrid solar systems has opened up for many interesting innovations. New inverters let homeowners take advantage of changes in the utility electricity rates throughout the day.Solar panels happen to output the most electrical power at noon – not long before the price of electricity peaks. Your home and electrical vehicle can be programmed to consume power during off-peak hours (or from your solar panels).Consequently, you can temporarily store whatever excess electricity your solar panels in batteries, and put it on the utility grid when you are paid the most for every kWh.Smart solar holds a lot of promise. The concept will become increasingly important as we transition towards the smart grid in the coming years. Equipment for Hybrid Solar SystemsTypical hybrid solar systems are based on the following additional components:

Charge Controller Battery Bank DC Disconnect (additional) Battery-Based Grid-Tie Inverter Power Meter

 Battery-Based Grid-Tie InverterHybrid solar systems utilize batter-based grid-tie inverters. These devices combine can draw electrical power to and from battery banks, as well as synchronize with the utility grid. The bottom line is this: Right now, for the vast majority of homeowners, tapping the utility grid for electricity and energy storage is significantly cheaper and more practical than using battery banks and/or backup generators.

What Factors Determine Solar Panel Efficiency? Solar panel efficiency, or conversion rate, refers to how much of the incoming solar energy is converted into electrical power. Typically, the efficiency of commercial solar panels operates in the range 11-15%.What are the most efficient solar panels? The most efficient solar cell to this date is based on a multi-junction concentrator and converts 44.0% of incoming solar energy into electricity.[1] The highest performing solar panels on the U.S. market today is SunPower SPR-327NE-WHT-D with a module efficiency of 20.1%.[2]

SunPower SPR-343J-WHT-D and SPR-343NJ-WHT-D have been confirmed at 21.0%, but these are currently not in production.Update June, 2013: Newly released SunPower X21-345 operates at record-breaking 21.5%.[4]

The efficiency of solar panels is influenced by a whole host of variables. The following are the most important ones: Solar Panel Type

Monocrystalline solar panels are based on the highest-purity silicon available. This makes them the most efficient solar panel type available for homeowners.

Solar panels based on polycrystalline silicon are usually not quite as efficient as monocrystalline, but there is not that much of a difference.

Today`s thin-film solar panels are relatively inefficient, but they also cost less. Thin-film solar panels take up a lot more space than mono- or polycrystalline solar panels, which is why they are unsuited for most households.

The efficiency of individual solar cells (not entire solar panels/modules) is typically higher. For a complete overview over the development of the different types of solar panels over the years check out Best Research-Cell Efficiencies (NREL). ShadeShade will obviously affect the output of solar panels. Depending on your setup, a little shade can even bring down an entire solar system. Micro-inverters offer a possible solution to shading issues.Professional solar panel installers will do a thorough analysis of shading in your specific situation.//Retrieve session data

What do I need to know about the solar panel installation? Labor Costs of Installing Solar Panels

The total costs of a typical solar panel system of 5kW (15 – 25 solar panels), is typically somewhere around $30,000. According to Lawrence Berkley National Laboratory (LBNL), average cost of labor is $0.59/W – about 10% of total system costs ($6.19/W).[1] You should expect to pay around $3,000 in labor costs for a 5kW solar system.Total labor costs ($0.59/W) consists of electrician installation labor ($0.33/W) and non-electrician installation labor ($0.26/W).[1]

The price varies tremendously depending on where you live. Solar is about half as cheap in Germany. This is not because the solar modules themselves are cheaper there, but because soft costs (non-hardware) in the U.S. are exceptionally high. Labor costs are 0.36/W cheaper in Germany.[1]

Why is the labor of a solar panel installation cheaper in Germany? Installers rarely install systems that require roof-penetration. Residential systems are larger in Germany (economics of scale). Nationwide sales tax exemptions reduce installation costs. Average installation time is 39 hours in Germany versus 75 hours in the U.S.[1]

Solar Panels and Installation Time The total installation time for a standard 3-kilowatt solar system of about 20 solar panels

is usually somewhere between 1 and 3 days. Average labor time is 75 man-hours, which can be further broken down into electrician installation labor (49 man-hours) and non-electrician installation labor (26 man-hours).

However, the time from you deciding to go solar to the solar panels are up on your roof can be longer. The design of the solar system and other lead-up work adds time to the process.

In most places, we`re looking at a couple of weeks, but depending on region, how long it takes to get permits there and how developed the solar market is, it can actually take several months.

The complexity of the solar system can also lengthen the installation process. A solar system with a battery backup is more complex and will add a couple of hours of labor. In many cases, the utility has to set up a bidirectional electric meter for net-metering.

Labor costs average at about 10% of total system costs. [2] Several companies are working to make solar installations more efficient and cheaper. SOLON`s SOLquick flat

roof installation “has proven to reduce mechanical installation time by over 85 percent and electrical installation time by 50 percent”, which granted the German solar company the Intersolar Award in June 2012.[1]

Can I Install Solar Panels Myself?A professional solar panel installation is typically around 10% of total solar system costs [1] – there`s potentially a lot of money to be saved if you install the solar system on your own. This article will cover the benefits and drawbacks of do-it-yourself solar panel installations. Can I really install solar panels without professional help?A handyman with enough skills should be able to design, size and install a residential solar system. The more you can yourself, the less expensive. However, we generally recommend hiring a certified professional to do the wiring and metering.Connecting a solar system to the electrical grid is no joke and can lead to serious injuries or even death. Only a certified installer is legally allowed to do so. Depending on the complexity of your solar system, where you live, and what regulations and policies apply, you will likely need your solar panel installation certified. Without a certification, it can be problematic to use the feed-in tariff and take advantage of financial incentives.The North American Board of Certified Energy Practitioners (NABCEP) is the “gold standard” for solar panel installation and certification in the U.S. Check with DSIRE to see if NABCEP-certification is a requirement where you live.UK solar panel manufacturers and installers need a certification called the Microgeneration Accreditation Scheme (MCS) to legally connect their customers to UK`s feed-in tariff scheme. What about DIY plug and play solar panel kits?In the last couple of years, a handful of solar companies have introduced plug and play solar panel kits on the market. These solar panels go into 120V power outlets, just like a home appliance, and there`s no need for a professional installer.Industry professionals have warned against consumer-installed, grid-tied solar panels for a long time – has the technology matured?About three years ago, Clarian Technologies announced they would have a 200W plug-in solar panel kit for $800 on the market within a year. I have tried contacting the company multiple times without luck since then. SpinRay Energyand GoGreenSolar have recently released similar products on the market.

Maintenance and lifespan of a solar panel system:

Best Way to Clean Solar Panels Solar panels does not have any moving parts, which is why there`s not a whole lot of maintenance to take care of. However, cleaning is one aspect of solar panel maintenance that should not be taken lightly. In this article you will learn how to clean solar panels the right way.

How to Clean Solar Panels

1. The first thing you want to do is to check with your solar panel manufacturer. They might have specific recommendations for cleaning.

2. Solar panels can become incredible hot in sunshine. Either clean your solar panels in the morning/afternoon, or pick a relatively cool day.

3. First try if your garden hose alone does the job. If a lot of dust and dirt has accumulated you might need to clean more thoroughly.

4. Fill a bucket or spray bottle with warm water and soap – no other special equipment is needed.

5. Clean the surface of the solar panel with a soft cloth or sponge. You do not have to clean the wiring underneath.

Show extra caution if cleaning your solar panels requires you to climb up on the roof.  Consider getting professional solar panel cleaners to do the job. Why should I clean my solar panels? We know that dust, dirt, pollen, bird droppings and other debris can negatively affect solar panel efficiency.Google conducted a groundbreaking experiment at their 1.6 MW solar farm in Mountain View, California. They found that cleaning the solar was “the number one way to maximize the energy they produce.” Cleaning solar panels that had been in operation for 15 months doubled their output of electricity.[1]

The same study also found that rain is not a satisfying way of cleaning solar panels. Solar panels that were cleaned professionally had a 12% higher output of electricity compared to those cleaned by rain.[2]

//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> How much money would it cost me to neglect solar panel cleaning? It is reasonable to assume that solar panels can loose 15-25% of their efficiency if not cleaned properly. This literally means that they will generate 15-25% less electricity, which you now will have to source from the utility company at their price rates. This easily adds a couple of years extra on the payback time. How often should I clean my solar panels? In most places, there`s more pollution in the winter, which is why the spring is a good time to do an annual cleaning. Solar panels that are cleaned once and twice a year produce 3.5% and 5.1% more electricity respectively than those that are left uncleaned.[3] However, some places do require extra attention:In the southwest region of the U.S., where rainfall is limited for several months at a time, the accumulation of dirt is far greater. Solar panels that are installed near sources of pollution such as freeways, factories and airports need to be cleaned more often. Other special cases to consider include autumn and winter, where the removal of leaves and snow is important for optimal performance.

Another thing to note is that rainwater has an easier time cleaning solar panels that are tilted (as opposed to flat mounted solar panels).Here`s the best piece of advice when it comes to frequency: Monitor changes in the power output of your solar panels before and after cleaning. Experiment with different time intervals. Take note and evaluate what works. Cleaning solar panels is not really that much different than cleaning a typical window. It is not very time-consuming either. Neglecting to clean your solar panels is not much different than throwing money out of the window.Self-cleaning solar systems are available for those lazy folks out there that are willing to spend the extra buck.//Retrieve session data

The Real Lifespan of Solar Panels Solar panel manufacturers put a lot of effort into making their solar panels robust. They need to be able to withstand heat/cold cycles and heavy weather. However, solar panels are not perfect and they will inevitably age. Keep reading to find out how age affects performance and what this actually means. How fast do solar panels degrade/loose their efficiency?The rated power output of solar panels typically degrades at about 0.5%/year. However, thin-film solar panels (a-Si, CdTe and CIGS) degrades faster than panels that are based on mono- and polycrystalline solar panels:

Solar cell type Output loss in percent per year

Pre Post

Amorphous silicon (a-Si) 0.96 0.87

Cadmium telluride (CdTe) 3.33 0.4

Copper indium gallium selenide (CIGS) 1.44 0.96

Monocrystalline silicon (mono-Si) 0.47 0.36

Polycrystalline silicon (poly-Si) 0.61 0.64

 Pre and Post refer to installations prior to and post 2000. Data is taken from Photovoltaic Degradation Rates — An Analytical Review NREL.[1]

Solar panels typically degrade faster in the first couple of years of their life. What is the life expectancy of solar panels?Below is a chart showing different solar panel warranties on the market today. The different manufacturers guarantees that the performance of their solar panels will stay above the following ranges:

The majority of manufacturers offer the 25-year standard solar panel warranty, which means that power output should not be less than 80% of rated power after 25 years.For more information on solar panel warranties, go to Solar Panel Warranty Comparison.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> What will happen to my solar panels after 25 years?The truth is we don`t really know – there`s not really a lot of data to look at since photovoltaics is a relatively new technology (the vast majority of all solar panels are less than 10 years old).

However, from what we are seeing so far, we have reason to be excited. Here are a couple of interesting reports:

A 33W solar panel (Arco Solar 16-2000) actually outperformed it`s original factory specifications 30 years after it was manufactured.[2]

World`s first modern solar panel still works after 60 years.[3] Kyocera has reported several solar power installations that continue to operate reliably

and generate electricity even though they are nearly 30 years old.[4]  The technology has improved, the solar panels on today`s market are more robust and durable.This is where it gets really interesting. What does all of this actually mean? The lifespan of a modern solar panel is far longer than the 20 years that we use to calculate costs and earnings. This basically translates into more money in your pocket.I would bet that a solar panel installed today would be up and running (and still generating a good amount of electricity) 30 – 40 years down the line.Note that batteries and inverters typically have to be replaced every 5 to 10 years. What can I do to extend the life of my solar panels?

Avoid physical damage (e.g. trees and bushes blowing in the wind and creating scratches). The more surface scratches, the more performance degradation. In the worst-case, water can seep through the surface, which can short-circuit the solar panels.

Regular maintenance and cleaning is important. For in-depth information on the subject, check out Best Way to Clean Solar Panels.

The more weather and wind the solar panels are exposed to, the faster they will degrade (e.g. think about shelter from the wind when evaluating placement).

//Retrieve session dat Are Solar Panels Affected by Weather?

 Solar panels are built to withstand heavy rain, hail, wind and cycles of heat and cold for many years. Every now and then we get questions related to solar panels and weather damage, so we did a quick write-up on the subject:Shade obviously affects the output of solar panels. Read more about this in Factors That Determine Solar Panel Efficiency. This article is about how weather potentially can damage solar panels. Solar panels go through rigorous testingISO, UL, IEC/EN, and CSA are some of the certifications and standards that are used to qualify solar panels. See the video below from Westpak, an independent testing laboratory based in California, to get an idea of how some of the tests in the solar industry are conducted:To be eligible for state rebates your solar panels and the installation itself has to be compliant with local building codes – the National Electric Code (NFPA 70)[1] in most places. The NFPA 70 specifies that you need a solar panel that is UL certified (or one that is certified from another approved testing lab).However, the federal government does not specify UL certification, which means that in some places you could still get your federal rebate. Can hail, lightening or wind damage my solar panels?Solar panels can be damaged from heavy hailstorms, but this is very rare.Most of the solar panels on the U.S. market are UL listed, which means they`ve gone through testing to withstand hail.

However, the main point of the hail test is to make sure that the glass doesn’t put people in danger by exploding (the glass can still break and pass). Hail is simulated with a one inch steel ball at terminal velocity that strikes the solar panels at an angle of 90 degrees.Although miniscule, there certainly is a possibility that lightening can damage your solar panels. Proper grounding is a requirement set by the National Electric Code, but there is not really anything we can do to protect ourselves 100% in the case of a lightening strike.Wind damage is also rare. Solar power companies found that their customers` solar panels held up very well against Hurricane Sandy when it struck most of the eastern United States in October 2012. Make sure that you go with a reputable solar installer that will mount your solar panels properly (whether it`s on the roof or on the ground).Chris Paxton, engineering leader at UL (Underwriters Laboratories) says the majority of failures happen when they expose solar panels to cycles of heat and cold in a humid environment. During the 10-day humidity freeze test, the solar panels are first exposed to 85 percent humidity (similar to the levels of humidity in the tropics), then they`re brought to an environment of negative 40 degrees Celsius (104°F). Does my solar panel warranty cover damage caused by weather?Generally speaking, solar panel warranties do not cover damage resulted from hail, lightening or wind, but most homeowner`s insurances do. Call your insurance provider to get up-to-date on their policies regarding solar panels and weather damage.

CompareWhat are the best technologies on the market today?

Which Solar Panel Type is Best? Mono- vs. Polycrystalline vs. Thin Film You are thinking about buying solar panels, but got confused about which type to go for? You’re at the right place. There’s a myriad of variables that you should take into account when you are buying a solar photovoltaic (PV) system – our job here at Energy Informative is to help you sort through them!If you want to find out which solar panel type is best for your situation, simply request a Free Solar Consultation.In this article, you will learn everything you need to know about the different types of solar panels for home use (mono-, polycrystalline and thin film).Let’s start with the different types of solar panels currently on the market, list their benefits and downsides, and then look at a few typical scenarios where certain types would be the better than others (hopefully one of them resonates with you). Contents

Crystalline Silicon Monocrystalline Polycrystalline Thin-Film Solar Panels Building Integrated Photovoltaics Best Solar Panel Type for Home Use

The term solar panels will be used to describe photovoltaic solar panels (the type that generates electricity), not solar thermal collectors.   Crystalline Silicon (c-Si)

Almost 90% of the World’s photovoltaics today are based on some variation of silicon. [1] In 2011, about 95% of all shipments by U.S. manufacturers to the residential sector were crystalline silicon solar panels.[2]

The silicon used in PV takes many forms. The main difference is the purity of the silicon. But what does silicon purity really mean? The more perfectly aligned the silicon molecules are, the better the solar cell will be at converting solar energy (sunlight) into electricity (the photoelectric effect).The efficiency of solar panels goes hand in hand with purity, but the processes used to enhance the purity of silicon are expensive. Efficiency should not be your primary concern. As you will later discover, cost-and space-efficiency are the determining factors for most people.Compare Solar Panels is the most comprehensive and up-to-date solar panel comparison service on the Internet. Compare the specifications of 10,000+ solar modules. Solar Cell Comparison Chart provides a quick overview over the different cell types, their benefits and how they compare against each other.Crystalline silicon forms the basis of mono- and polycrystalline silicon solar cells: Monocrystalline Silicon Solar CellsSolar cells made of monocrystalline silicon (mono-Si), also called single-crystalline silicon (single-crystal-Si), are quite easily recognizable by an external even coloring and uniform look, indicating high-purity silicon, as you can see on the picture below:

//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!

';}?> Monocrystalline solar cells are made out of silicon ingots, which are cylindrical in shape. To optimize performance and lower costs of a single monocrystalline solar cell, four sides are cut out of the cylindrical ingots to make silicon wafers, which is what gives monocrystalline solar panels their characteristic look.A good way to separate mono- and polycrystalline solar panels is that polycrystalline solar cells look perfectly rectangular with no rounded edges. Advantages

Monocrystalline solar panels have the highest efficiency rates since they are made out of the highest-grade silicon. The efficiency rates of monocrystalline solar panels are typically 15-20%. SunPower produces the highest efficiency solar panels on the U.S. market today. Their E20 series provide panel conversion efficiencies of up to 20.1%.[3]  Update (April, 2013): SunPower has now released the X-series at a record-breaking efficiency of 21.5%. [7]

Monocrystalline silicon solar panels are space-efficient. Since these solar panels yield the highest power outputs, they also require the least amount of space compared to any other types. Monocrystalline solar panels produce up to four times the amount of electricity as thin-film solar panels.

Monocrystalline solar panels live the longest. Most solar panel manufacturers put a 25-year warranty on their monocrystalline solar panels.

Tend to perform better than similarly rated polycrystalline solar panels at low-light conditions.

The efficiency of individual solar cells is higher than for entire solar panels/modules. For a complete overview over how the efficiency rates of the various solar cell technologies have advanced since 1975 check out Best Research-Cell Efficiencies (NREL). The efficiency rates in this article refer to solar panel/module efficiencies. Check out What Factors Determine Solar Panel Efficiency? for more information on this subject. Disadvantages

Monocrystalline solar panels are the most expensive. From a financial standpoint, a solar panel that is made of polycrystalline silicon (and in some cases thin-film) can be a better choice for some homeowners.

If the solar panel is partially covered with shade, dirt or snow, the entire circuit can break down. Consider getting micro-inverters instead of central string inverters if you think coverage will be a problem. Micro-inverters will make sure that not the entire solar array is affected by shading issues with only one of the solar panels.

The Czochralski process is used to produce monocrystalline silicon. It results in large cylindrical ingots. Four sides are cut out of the ingots to make silicon wafers. A significant amount of the original silicon ends up as waste.

Monocrystalline solar panels tend to be more efficient in warm weather.Performance suffers as temperature goes up, but less so than polycrystalline solar panels. For most homeowners temperature is not a concern.

This article is solely about different types of solar panels. If you want to learn about what other equipment a photovoltaic system consists of, go to Grid-Tied, Off-Grid and Hybrid Solar Systems. 

Polycrystalline Silicon Solar CellsThe first solar panels based on polycrystalline silicon, which also is known as polysilicon (p-Si) and multi-crystalline silicon (mc-Si), were introduced to the market in 1981. Unlike monocrystalline-based solar panels, polycrystalline solar panels do not require the Czochralski process. Raw silicon is melted and poured into a square mold, which is cooled and cut into perfectly square wafers.

 Advantages

The process used to make polycrystalline silicon is simpler and cost less. The amount of waste silicon is less compared to monocrystalline.

Polycrystalline solar panels tend to have slightly lower heat tolerance than monocrystalline solar panels. This technically means that they perform slightly worse than monocrystalline solar panels in high temperatures. Heat can affect the performance of solar panels and shorten their lifespans. However, this effect is minor, and most homeowners do not need to take it into account.

 Disadvantages

The efficiency of polycrystalline-based solar panels is typically 13-16%.Because of lower silicon purity, polycrystalline solar panels are not quite as efficient as monocrystalline solar panels.

Lower space-efficiency. You generally need to cover a larger surface to output the same electrical power as you would with a solar panel made of monocrystalline silicon. However, this does not mean every monocrystalline solar panel perform better than those based on polycrystalline silicon.

Monocrystalline and thin-film solar panels tend to be more aesthetically pleasing since they have a more uniform look compared to the speckled blue color of polycrystalline silicon.

 String Ribbon Solar CellsString Ribbon solar panels are also made out of polycrystalline silicon. String Ribbon is the name of a manufacturing technology that produces a form of polycrystalline

silicon. Temperature-resistant wires are pulled through molten silicon, which results in very thin silicon ribbons. Solar panels made with this technology looks similar to traditional polycrystalline solar panels.Evergreen Solar was the main manufacturer of solar panels using the String Ribbon technology. The company is now bankrupt, rendering the future for String Ribbon solar panels unclear. Advantages

The manufacturing of String Ribbon solar panels only uses half the amount silicon as monocrystalline manufacturing. This contributes to lower costs.

 Disadvantages

The manufacturing of String Ribbon solar panels is significantly more energy extensive and more costly.

Efficiency is at best on par with the low-end polycrystalline solar panels at around 13-14%. In research laboratories, researchers have pushed the efficiency of String Ribbon solar cells as high as 18.3%.[3]

String Ribbon solar panels have the lowest space-efficiency of any of the main types of crystalline-based solar panels.

 Thin-Film Solar Cells (TFSC)Depositing one or several thin layers of photovoltaic material onto a substrate is the basic gist of how thin-film solar cells are manufactured. They are also known as thin-film photovoltaic cells (TFPV). The different types of thin-film solar cells can be categorized by which photovoltaic material is deposited onto the substrate:

Amorphous silicon (a-Si) Cadmium telluride (CdTe) Copper indium gallium selenide (CIS/CIGS) Organic photovoltaic cells (OPC)

 Depending on the technology, thin-film module prototypes have reached efficiencies between 7–13% and production modules operate at about 9%.Future module efficiencies are expected to climb close to the about 10–16%.[4] The market for thin-film PV grew at a 60% annual rate from 2002 to 2007. [5]  In 2011, close to 5% of U.S. photovoltaic module shipments to the residential sector were based on thin-film.[1]

 Advantages

Mass-production is simple. This makes them and potentially cheaper to manufacture than crystalline-based solar cells.

Their homogenous appearance makes them look more appealing. Can be made flexible, which opens up many new potential applications. High temperatures and shading have less impact on solar panel performance. In situations where space is not an issue, thin-film solar panels can make sense.

 Disdvantages

Thin-film solar panels are in general not very useful for in most residential situations. They are cheap, but they also require a lot of space. SunPower`s monocrystalline solar panels produce up to four times the amount of electricity as thin-film solar panels for the same amount of space.[3]

Low space-efficiency also means that the costs of PV-equipment (e.g. support structures and cables) will increase.

Thin-film solar panels tend to degrade faster than mono- and polycrystalline solar panels, which is why they typically come with a shorter warranty.

 Solar panels based on amorphous silicon, cadmium telluride and copper indium gallium selenide are currently the only thin-film technologies that are commercially available on the market: Amorphous Silicon (a-Si) Solar CellsBecause the output of electrical power is low, solar cells based on amorphous silicon have traditionally only been used for small-scale applications such as in pocket calculators. However, recent innovations have made them more attractive for some large-scale applications too.With a manufacturing technique called “stacking”, several layers of amorphous silicon solar cells can be combined, which results in higher efficiency rates (typically around 6-8%).Only 1% of the silicon used in crystalline silicon solar cells is required in amorphous silicon solar cells. On the other hand, stacking is expensive.

Read more about this technology in Amorphous Silicon Solar Panels. Cadmium Telluride (CdTe) Solar CellsCadmium telluride is the only thin-film solar panel technology that has surpassed the cost-efficiency of crystalline silicon solar panels in a significant portion of the market (multi-kilowatt systems).The efficiency of solar panels based on cadmium telluride usually operates in the range 9-11%.First Solar has installed over 5 gigawatts (GW) of cadmium telluride thin-film solar panels worldwide. The same company holds the world record for CdTe PV module efficiency of 14.4%.[6]  Copper Indium Gallium Selenide (CIS/CIGS) Solar CellsCompared to the other thin-film technologies above, CIGS solar cells have showed the most potential in terms of efficiency. These solar cells contain less amounts of the toxic material cadmium that is found in CdTe solar cells. Commercial production of flexible CIGS solar panels was started in Germany in 2011.The efficiency rates for CIGS solar panels typically operate in the range 10-12 %.Many thin-film solar cell types are still early in the research and testing stages. Some of them have enormous potential, and we will likely see more of them in the future.Learn more about thin film solar panels here: Best Thin Film Solar Panels – Amorphous, Cadmium Telluride or CIGS? Building-Integrated Photovoltaics (BIPV)Lastly, we`ll briefly touch on the subject of building integrated photovoltaics. Rather than an individual type of solar cell technology, building integrated photovoltaics have several subtypes (or different methods of integration), which can be based on both crystalline-based and thin-film solar cells.Building integrated photovoltaics can be facades, roofs, windows, walls and many other things that is combined with photovoltaic material. If you have the extra money and want to seemlessly integrate photovoltaics with the rest of your home, you should look up building integrated photovoltaics. For most homeowners it`s simply way too expensive.This article covered the advantages and disadvantages of different solar panel types. If you want to learn more solar power in general, go to Solar Energy Pros and Cons. Best Solar Panel Type for Home UseHaving your particular situation evaluated by an expert would be the best way to find out what solar panel type would be best for your household. Here are some of the typical scenarios we see: Limited SpaceFor those who don’t have enough space for thin-film solar panels (the majority of us), or if you want to limit the amount of space their PV-system takes up, crystalline-based solar panels are your best choice (and they would likely be the your best choice even if you had the extra space). There are not a whole lot of solar installers and providers that offer thin-film solar panels for homeowners at this point.You will have a choice of different solar panel sizes. The 180, 200 and 220-watt rated solar panels are usually physically the same size. They are manufactured exactly the same way, but under- or overperform when tested, hence ending up in different categories for power output. If size is important, you should go for the highest rated power output for a particular physical size.Both mono- and polycrystalline solar panels are good choices and offer similar advantages. Even though polycrystalline solar panels tend to be less space-efficient and

monocrystalline solar panels tend to produce more electrical power, this is not always the case. It would be nearly impossible to recommend one or the other by not examining the solar panels and your situation closer.Monocrystalline solar panels are slightly more expensive, but also slightly more space-efficient. If you had one polycrystalline and one monocrystalline solar panel, both rated 220-watt, they would generate the same amount of electricity, but the one made of monocrystalline silicon would take up less space.We always keep an up-to-date list over the most efficient solar panels on the market today: What are the Most Efficient Solar Panels? Lowest CostsIf you want the lowest costs per rated power, or in other words, pay as little as possible for a certain amount of electricity, you should investigate if thin-film solar panels could in fact be a better choice than mono- or polycrystalline solar panels.To see w

Solar Cell Comparison Chart – Mono-, Polycrystalline and Thin Film Below is a chart that lists the most used solar cell technologies today, their

specifications, and how they compare against each other. Thin film solar cells include amorphous silicon, cadmium telluride (CdTe) and copper indium gallium selenide (CIS/CIGS).

Monocrystalline Polycrystalline Amorphous CdTe CIS/CIGS

Typical module efficiency

15-20% 13-16% 6-8% 9-11% 10-12%

Best research cell efficiency

25.0% 20.4% 13.4% 18.7% 20.4%

Area required for 1 kWp

6-9 m2 8-9 m2 13-20 m211-13 m2

9-11 m2

Typical length of warranty

25 years 25 years 10-25 years

Lowest price 0.75 $/W 0.62 $/W 0.69 $/W

Temperature resistance

Performance drops 10-15% at high temperatures

Less temperature resistant than monocrystalline

Tolerates extreme heat

Relatively low impact on performance

Additional details

Oldest cell technology and

Less silicon waste in the

Tend to degrade faster than crystalline-based solar panels

Monocrystalline Polycrystalline Amorphous CdTe CIS/CIGS

most widely usedproduction process

Low availability on the market

  Lowest price is based on listings of wholesalers and retailers on the Internet (June 3,

2013). Best research cell efficiency is data collected from National Renewable Energy Laboratory (NREL).[1]

For in-depth information on the differences between mono-, polycrystalline and thin film, I suggest you look at Which Solar Panel Type is Best? Mono- vs. Polycrystalline vs. Thin Film. For factors that determine efficiency, and to learn the difference between cell and module efficiency, check out What Factors Determine Solar Panel Efficiency?.

Micro-Inverters vs. Central Inverters

Micro-Inverters vs. Central InvertersLast updated June 19, 2013 by Mathias Aarre Maehlum 6 CommentsCentral inverters have dominated the solar industry since its inception. The introduction of micro-inverters marks one of the biggest technology shifts in the PV industry to date. Manufacturers are touting 5-25% increase in power output, which in the long run can bring in a lot in savings for many homeowners.For a list over the best performing inverters on the market today, go toMost Efficient Solar Panel Inverters 2013. What is a Micro-Inverter?Although micro-inverters have been available since 1993, Enphase Energy is regarded as the company that first built a commercially successful micro-inverter. More than one million units of the Enphase M175 have been sold since its release in 2008. [1]

Several other companies in the solar industry have followed suit and launched their own micro-inverters, validating their potential.Since your solar panels generate DC (direct current), we need some kind of device to convert DC intto AC (alternating current), in order to power your electrical appliances (without burning down your house!). This is where the solar inverter comes in.Inverters also enable us to switch off all electrical current in the case of a blackout or if repair is needed. This is of course also useful for maintenance, troubleshooting and system upgrade as well.One central (string) inverter would normally cover an entire residential solar system (assuming that the central inverter is strong enough for your entire array). Micro-inverters, on the other hand, sit on the back of each and every solar panel.Micro-inverters bring several significant benefits to the table. Do these benefits outweigh the extra costs?//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!

';}?> BenefitsIndividual OptimizationMicro-inverters optimizes for each solar panel alone, not for your entire solar system, as central inverts do. This enables every solar panel to perform at their maximum potential. In other words, one solar panel alone cannot drag down the performance of entire solar array, as opposed to central inverters that optimize for the weakest link.Shading of as little as 9% of a solar system connected to a central inverter, can lead to a system-wide decline in power output with as much as 54%.[2]  If one solar panel in a string had abnormally high resistance due to a manufacturing defect, the performance of every solar panel connected to that same central inverter would suffer.Likewise, coverage issues such as shading, dirt, snow and even slight orientation mismatch on one of the solar panels would not bring the entire solar system down.

 Maximum Power Point Tracking (MPPT)One of the tricky things about solar cells is that voltage needs to be adjusted to light level for maximum output of power. In other words, the performance of a solar panel is dependent on the voltage load that is applied from the inverter.MPPT is a technique used to find the right voltage – the maximum power point. When MPPT is applied to each individual panel, as opposed to the solar system as a whole, performance will naturally increase. Longer WarrantySince micro-inverters are not exposed to as high power and heat loads as central inverter, they also tend to last significantly longer. Micro-inverters typically come with a warranty of 20-25 years – 10-15 years longer than central inverters. Easily ExpandableExpanding your solar system with more solar panels later on is easier with micro-inverters. You don’t have to worry about restringing or getting a second central inverter installed.Central inverters come in limited sizes – you might end up having to pay for one that is much bigger than what you actually need. Performance ReportsWeb-based monitoring on a panel-by-panel basis is usually available both for homeowner and installer. Continuously analyzing the health of the solar system can pave the way for additional tweaks and performance improvements. There are even mobile applications that enable you to monitor your PV system when on the road.

 No Single Point of FailureUnlike central inverters, if there is something wrong with either one of the solar panels or the micro-inverter that sits on the back of it, the rest of the solar system is unaffected and still up and running. Improved SafetySolar panels are connected in series before they are fed into a central inverter, typically with an effective nominal rating of 300-600 VDC (volts of direct current). This current is potentially life threatening.Micro-inverters eliminate the need for high voltage DC wiring, which improve the safety for both solar installers and system owners. SilentSince micro-inverters dissipate significantly less heat than central inverters do, there is no need for active cooling, which enables them to operate without noise. How Much Micro-Inverters CostMicro-inverters are flat down more expensive than central inverters.Numbers from 2010 reveal that central inverters averaged at $0.40/Wp (watt-peak), while the price of micro-inverters significantly higher at $0.52/Wp.Higher initial cost per watt-peak does not necessarily mean micro-inverters are ultimately going to cost more. Several other factors have to be taken into account.Solar installations with micro-inverters are simpler and less time consuming, which typically cut 15% of the installation costs. Better durability and longer lifespan should also be considered. Dual Micro-InvertersIn 2011, dual micro-inverters were introduced to the market. They essentially do exactly the same as regular micro-inverters, only on two solar panels instead of one. This lowers costs, but at the price of performance. Are micro-inverters, dual micro-inverters, or a central string invert the better choice in your particular situation? It depends. In certain situations, micro-inverters should clearly be given serious consideration.The homeowners who are more affected by shading are also those that can benefit the most from micro-inverters. Micro-inverters are also excellent for difficult roof orientations, starter systems and small applications. Cost Analysis is NecessaryWe evaluate the usefulness of micro-inverters by looking at two numbers:

Lifetime costs ($) Lifetime energy production (kWh)

This is essentially what it all comes down – divide costs by energy production and you`re left with how much money you have to pay for every kWh your solar system produce. Every situation is different – there are a lot of variables to take into account in order to find those two numbers. Enecsys, one of the leading micro-inverter manufacturers, sums it up nicely:“A total cost of ownership analysis of a PV solar system can only be carried out after detailed examination of capital and maintenance costs, and an understanding of how much energy will be harvested over the life of the system.”[3]

For help to determine if micro-inverters can benefit your situation, sign up for aFree Solar Consultation.

Best Thin Film Solar Panels – Amorphous, Cadmium Telluride or CIGS? Thin film solar panels accounted for 11% of all solar panel sales in 2011.[1]Production capacity is expected to grow at an annual rate of 24%, reaching more than 22 GW by 2020 (or a global market share of 38% in terms module production).[2]

There are three primary types of thin film solar panels on the market today:Amorphous silicon (a-Si), cadmium telluride (CdTe) and copper indium gallium selenide (CIS/CIGS). In the overview chart below you can see their main characteristics:

a-Si CdTe CIGS

Best research-cell efficiency

13.4% [3] 19.0% [3] 20.4% [3]

Best solar module efficiency

8.1% 14.4%[5] 14.5%[6]

Thin film market share

32% [2] 43% [2] 25% [2]

Advantages

Mature technologyExcellent for small devices (e.g. pocket calculators)

Low cost manufacturing

High efficiencyGlass or flexible substrates

DisadvantagesLow efficiencyHigh cost equipment

Medium efficiencyRigid glass substratesCadmium is highly toxic

Costly traditional processMarket share expected to growRequires less cadmium than CdTe solar cells.

Major manufacturers

Sharp First Solar Solar Frontier

 Protocrystalline, nanocrystalline (nc-Si), black silicon, dye-sensitized solar cells (DSC) and other organic solar cells will not be covered in this article. These technologies still have a long way to go in research and development before they are ready for the market. Amorphous silicon (a-Si), cadmium telluride (CdTe) and copper indium gallium selenide (CIS/CIGS) have several other benefits and downsides in addition to what you read in the chart above:Advantages

Significantly higher temperature resistance compared to crystalline-based solar panels. Many thin-film modules are flexible, which greatly increases the number of potential

applications (e.g. curved surfaces, building-integrated photovoltaics). Better resistance against shading.

Disadvantages Lower efficiency rates mean you need a physically larger system for the same power

output. Installation costs goes up because you need to install more solar panels. Thin film solar panels tend to degrade faster. Silicon costs are declining and silicon-based solar panels (e.g. mono- and

polycrystalline) are becoming more affordable.Read more about solar panel types (including mono- and polycrystalline) in Which Solar Panel Type is Best? Mono-, Polycrystalline or Thin Film? Amorphous silicon (a-Si)

The first thin film solar cells were based on amorphous silicon. The technology is most commonly used in devices that require very little power (e.g. pocket calculators) because of low efficiency rates.The future of larger-scale amorphous silicon solar panels does not look very bright: Sharp retired 160 out of their 320 MW production capacity in Japan earlier this year.Optisolar, Signet Solar, Unisolar, and many other companies that were touting the amorphous technology are acquired, bankrupt or closed.Energy Matters, one of the leading solar installers in Australia, recommend amorphous thin film solar panels for their customers in far North Queensland and the Northern Territory due to performance advantages in high temperatures (better heat resistance).Learn more about this technology in Amorphous Silicon Solar Panels. Cadmium Telluride (CdTe)

It’s all about First Solar when it comes to cadmium telluride solar panels. Abound Solar has declared bankruptcy and General Electric`s PrimeStar is failing. First Solar is the world-record holder for CdTe thin film module (14.4%) and cell (18.7%) efficiency, and backs their solar panels with a limited 25-year power output warranty. [5] The company is currently building a 230 MW solar power plant in Antelope Valley and looks to generate $0.8 billion to $1.0 billion of operating cash flow in 2013.[7]

In some situations, typically multi-kilowatt systems in higher temperatures, CdTe-based solar panels can beat mono- and polycrystalline solar panels in terms of costs.There are, however, environmental issues with products that rely on cadmium – a heavy metal and potential carcinogen that can accumulate in plant and animal tissue. While the threat is minimal as long as the compound is contained within the solar panel, the disposal and recycling can be both dangerous and costly. Copper Indium Gallium Selenide (CIS/CIGS)

Solyndra, MiaSolé, Nanosolar, AQT, Solopower and many more – the list of CIS/CIGS companies that have failed goes on and on. In the midst of distress sales and bankruptcies, the Japanese manufacturer Solar Frontier seems to be doing something right. The company recently built out a 1 GW factory and shipped 577 MW worth of solar panels in 2011.The CIGS-technology might also see some success via Hanergy, a Chinese company that has gained a strong position in the thin film solar market through the acquisition of MiaSolé and Solibro.

In 2013, scientists at Empa, the Swiss Federal Laboratories for Materials Science and Technology, successfully created CIGS solar cells on flexible polymer foils with a new record efficiency of 20.4%. [3] This makes CIGS-based solar panels the highest performing thin film solar panels to date.Also worth mentioning is that less of the toxic material cadmium is present in CIGS solar cells (compared to solar cells made out of cadmium telluride). So, which thin film solar panel type is really the best? First of all, a mono- or polycrystalline solar panel is a better choice for the vast majority of homeowners. If you`re looking for a large-scale system, have the extra space required, and live in an area where the temperature is unusually high, thin film solar panels can make sense. If you want a flexible option, your options are amorphous silicon or CIGS.The next step would be to predict long-term earnings and costs of specific solar modules. Go for a product that is backed up with a good performance guarantee/warranty.If you want expert guidance to find out which solar panel is better in your situation, simply request a Free Solar Consultation.

What solar panels, inverters and manufacturers do you recommend? Solar Panel Comparison Tool (Updated June 2013)

Last updated June 23, 2013 by Mathias Aarre Maehlum 5 CommentsPower (PTC)The solar module`s DC power output under PVUSA Test Conditions:

Solar irradiance of 1,000 W/m² Air temperature at 25° C Wind speed of 1 m/s, 10 m above ground level

PTC is generally regarded as a better measure of solar panel performance because PVUSA Test Conditions are more realistic.Power (STC)The solar module`s DC power output under Standard Test Conditions:

Solar irradiance of 1,000 W/m² Cell temperature at 25° C AM of 1.5 (air mass) ASTM G173-03 standard spectrum

    EfficiencyA measure of how much of the solar energy that hits the solar module is converted into electricity under Standard Test Conditions (STC):Module Efficiency (%) = Power (STC) (W) / [Area (m²) x Irradiance (1,000 W/m²)]Note that the efficiency of any given solar panel is dependent on many different variables including, but not limited to, temperature, irradiance angle and wind speed. Performance is therefore not constant and will vary throughout the day and between seasons.The efficiency of an individual solar cell is typically higher than the efficiency of an entire solar module.Power DensityPower density under Standard Test Conditions (STC) is calculated using the following formula:Power Density (W/m²) = Power (STC) (W) / Area (m²)

A high power density, which is typically what you will find in mono- and polycrystalline solar modules indicate high area-efficiency. These are the types of solar panels someone with a limited roof should choose. Thin-film solar panels have low power density.      Cell TypeCell type refers to what photovoltaic technology and materials the solar module is based own:

Mono (Monocrystalline silicon) Poly (Polycrystalline silicon) CdTe (Cadmium telluride) a-Si (Amorphous silicon) a-Si + micro-c (Amorphous and microcrystalline silicon) CIS/CIGS (Copper indium gallium selenide) Ribbon (String ribbon – a type of polycrystalline)

String ribbon solar panels are no longer in production. The remaining types belongs to the category of thin-film solar cells, which typically aren`t good choices in residential situations.The majority of homeowners either go with mono- or polycrystalline silicon solar panels. Read more about the various solar cell types and their benefits in Which Solar Panel Type is Best? Mono- vs. Polycrystalline vs. Thin Film.CSI ApprovedWhether or not a solar module is compliant with California Solar Initiative`s SB1 Guidelines. Only CSI-compliant solar modules are eligible for incentives in California. Manufacturer and Module IDThe manufacturer and ID of the particular solar module you are looking at. Module IDs typically include rated power in standard testing conditions (STC). Length, Width, Area and WeightThese terms are all self-explanatory, but keep in mind that the values are based on the international system of units. Length and width are measured in millimeters (mm), area in square meters (m²) and weight in kilograms (kg). Temperature CoefficientThe temperature coefficient of a solar module is a measure of output loss or gain per degree Celsius (%/°C) starting at STC (25°C). Solar panels based on monocrystalline silicon are slightly more heat resistant compared to polycrystalline silicon. Thin-film solar panels tolerate heat well.

What Are the Most Efficient Solar Panels in 2013? We have categorized the best performing solar panels into three categories: Mono-,

polycrystalline and thin-film. You will find similar lists containing solar panels with higher efficiency ratings around the Internet, however these also include solar panels that no longer are in production. This is also true for our own solar panel comparison tool.

Efficiency is not the be-all end-all on the solar market today. Cost-effectiveness is usually a better criterion when looking for the best solar panels.

 

Top 6 Monocrystalline Solar Panels #

Manufacturer

Model Cell TechnologyModule Efficiency

1.

SunPower X21-345SunPower Maxeon

21.5%

2.

Sanyo HIT Double 195 Sanyo HIT 20.5%*

3.

SunPowerSPR-333NE-WHT-D

SunPower Maxeon

20.4%

4.

SunPowerSPR-327NE-WHT-D  

SunPower Maxeon

20.1%

5.

AUOSunForte PM318B00

19.5%

6.

Sanyo HIT Power 240S Sanyo HIT 19.0%

  *The back face of the Sanyo HIT Double solar panel is also used to generate electricity.

These solar panels are therefore only applicable in slanted, vertical and open-bottom horizontal installations.

 

Top 5 Polycrystalline Solar Panels #

Manufacturer Model Cell TechnologyModule Efficiency

1.

Phono Solar PS330P-24/T 17.0%

2.

Trina SolarTSM-310 (PC/PA14A)

Trina Solar Honey

16.0%

3.

Trina SolarTSM-260 (PC/PA05A)

Trina Solar Honey

15.9%

4.

Canadian Solar

CS6P (255P) 15.9%

5.

Siliken SLK60P6L   15.7%

 

Sunweb Solar (former Solland Solar) shut down their production of solar panels early 2012. They formerly produced high efficiency polycrystalline solar panels with module efficiencies up to 16.00%[1]

 

Top 5 Thin-Film Solar Panels

 # Manufacturer ModelCell Type

Module Efficiency

1. MiaSolé MS155GG-02 CIGS 14.5%

2. MiaSolé MS140GG CIGS 13.0%

3. Solar Frontier SF160-S CIS 13.0%

4. AvancisPowerMax SMART 135

CIS 12.6%

5. Global SolarPowerFLEX BIPV 300W

CIGS 12.6%

  Q-Cells stopped making CIGS thin-film modules and is no longer placing second on this

list with module efficiencies of up to 13.4%.   There are many different terms thrown around that cause massive confusion amongst

homeowners. Here`s a quick overview over them:   Solar Cell Efficiency Solar cell efficiencies measure the performance of individual solar cells – not the solar

panels themselves (modules). Unless otherwise is stated, solar cell efficiencies are measured under standard test conditions (STC).

According to NREL (November 2012), the highest performing solar cell has hit 44.0%. [2] In other words, the solar cell converts almost half the solar energy it is exposed to into electricity!

Although an important technological advancement in photovoltaics, this record was set under laboratory conditions, and is not applicable for homeowners.

SunPower, an American-based solar company that produces residential and commercial solar panels, set the world record of 24.2% for solar cells suitable for mass-production.[3]

  Solar Module Efficiency Module efficiency (not the efficiency of individual solar cells) is what homeowners should

be evaluating. SunPower announced earlier this year that they have started the production of solar

panels with the third generation Maxeon solar cell capable of cell efficiencies up to 24%.[4]   The result is the E20-series with module efficiencies of up to 20.4%. Update: SunPower released the X-series April this year at 21.5%.

Top 10 Cheapest (Best Value) Solar Panels

“What are the most efficient solar panels?” is a question we get asked all the time here at Energy Informative. Homeowners constantly get hung up in conversion rates (efficiency) of solar panels, but what they really should be looking at is price.

Most homeowners will get along fine without the best performing solar panels on the market (unless their roof space is very limited). What are the best value solar panels?

  Price per Watt Solar panel prices are often listed as cost per watt ($/Watt). This is a useful measure

when quickly comparing different solar panels, but is not the be-all end-all when determining the value of a complete solar system (more about this later).

The following table contains the ten cheapest solar panels from wholesalers and retailers on the Internet:

# Manufacturer ModelPower (STC)

PricePrice per Watt

1. Talesun TP660P-235 235W$183.30

$0.75

2.Canadian Solar

CS6P-235PX 235W$190.35

$0.81

3. EopllyE156P/60-230W

230W$204.70

$0.89

4. EopllyE156P/60-240BB

240W$213.60

$0.89

5. EopllyE156P/72-280W

280W$249.20

$0.89

6. Talesun TP660PB-240 240W$220.80

$0.92

7. Talesun TP660PB-245 245W$225.40

$0.92

8. Suniva MPV285 285W$262.20

$0.92

9. Jinko JKM-235P 235W$230.30

$0.98

10.

EcoSolargyECO230S156P-60

230W$227.70

$0.99

These prices are based on bulk purchases of a minimum of 25 solar modules – about the size of a large residential solar system (5 – 6 kW). Add 10-20% to the price if purchasing on panel-by-panel basis.

  Output is King Instead of evaluating a solar system by its capacity in kilowatts (kW), get your solar

advisor to quote how many kilowatt-hours (kWh) the solar system is expected to generate in its lifetime.  Divide this number with the cost of the system.

You are now left with how much you are paying for every kWh of electricity the solar panels produce ($/kWh). Divide again by hundred to get cents/kWh.

Electricity prices in the United States typically range from 8 to 17 cents/kWh. [1]

  If you`re just comparing two solar panels, and the length of their warranties is the same,

doing the same analysis for the first year (as opposed to their lifetime) is usually good enough.

Solar panels are typically warrantied for 20 to 25 years. The performance of solar panels slowly degrades over time. Solar manufacturers typically guarantee the power output of their solar panels to stay above 80% before the warranty expires.

 

Case Study

Details Solar System 1 Solar System 2

Manufacturer SunPower Canadian Solar

Model SPR-210-WHT-U CS6P-250P

Efficiency 16.9% 16.1%

# of Solar Panels 28 28

Output (Year One) 8,930 kWh 9,066 kWh

Total Cost $42,000 $38,000

Area 375 ft² (34.8 m²) 485 ft² (45.1 m²)

Value $4.70/kWh $4.19/kWh

  System 2 is superior from a financial standpoint and most homeowners would choose it

for this reason. System 1 is a good option for homeowners that lack roof space for a less efficient (but cheaper) solar system.

We generally see that the less efficient and cheaper solar panels tend to produce more electricity in a year for the same price as more expensive high-efficiency solar panels.

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Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today! ';

}?>

  If you want to look up the details for the specific solar modules, take a look at Solar

Panel Comparison - the largest database on the entire Internet where you can compare over 10,000 solar modules!

  The Bottom Line Any salesman will tell you that his solar panels are the best. Ask specifically for how

many kilowatt-hours they will produce, divide by total costs (not panels or labor exclusively), and then compare to offers from other solar installers in your area.

Most Efficient Solar Panel Inverters 2013 A solar inverter (PV inverter) is a crucial part of a solar panel system. Solar inverters are

used to convert DC (direct current) from your solar panels into utility frequency AC (alternating current) – the preferred type of current for the majority of electrical appliances today.

Here`s a list over the top 26 most efficient solar panel inverters on the market:

# Manufacturer Model Rating Efficiency

1 SMA America SB6000TL-US (240V) 6000W 98.5%

2 SMA AmericaSB6000TL-US-12 (240V)

6000W 98.5%

3 SMA America SB7000TL-US (240V) 7000W 98.5%

4 SMA AmericaSB7000TL-US-12 (240V)

7000W 98.5%

5Advanced Energy Industries

Solaron 500 HE (3159502-XXXX)

500000W 98%

6 Refusol 804R024 22230 98%

7 Siemens Industry SINVERT PVM24 UL 22230 98%

8 SMA America SB10000TL-US (240V) 10000W 98%

9 SMA AmericaSB10000TL-US-12 (240V)

10000W 98%

10

SMA America SB11000TL-US (240V) 11000W 98%

# Manufacturer Model Rating Efficiency

11

SMA AmericaSB11000TL-US-12 (240V)

11000W 98%

12

SMA America SB6000TL-US (208V) 6000W 98%

13

SMA AmericaSB6000TL-US-12 (208V)

6000W 98%

14

SMA America SB7000TL-US (208V) 7000W 98%

15

SMA AmericaSB7000TL-US-12 (208V)

7000W 98%

16

SMA America SB8000TL-US (240V) 8000W 98%

17

SMA America SB8000TL-US (208V) 8000W 98%

18

SMA AmericaSB8000TL-US-12 (240V)

8000W 98%

19

SMA AmericaSB8000TL-US-12 (208V)

8000W 98%

20

SMA America SB9000TL-US (240V) 9000W 98%

21

SMA America SB9000TL-US (208V) 9000W 98%

22

SMA AmericaSB9000TL-US-12 (240V)

9000W 98%

23

SMA AmericaSB9000TL-US-12 (208V)

9000W 98%

24

SolarEdge Technolgies

SE5000 (277V) 5000W 98%

25

SolarEdge Technolgies

SE6000 (277V) 6000W 98%

# Manufacturer Model Rating Efficiency

26

SolarEdge Technolgies

SE7000 (277V) 7000W 98%

Most Popular Solar Panel Brands Homeowners today have more than 150 different solar panel brands/manufacturers to

choose from – it sure can be confusing to go solar! The chart below should help you get an idea on what manufacturers are the most popular:

California leads the nation with 132,904 solar projects and 1,388 megawatts installed as of 11.28.12[1] – almost half the capacity of photovoltaics in the entire country. Data collected by the California Solar Statistics can therefore be used to pinpoint what solar panel manufacturers are the most popular in the United States.

American-based SunPower is the king of the throne with 844,727 (15.6 %) solar panels installed out of 5,427,850 total (in California). This company manufactures the highest performing solar panels on the market today and touts module efficiencies of up to 20.1%.[2] You can only get SunPower solar panels through certified solar installers.

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Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

Solar Panel Warranty Comparison  Which solar panel brands have the best warranties on the market?The majority of solar panels on today`s market come with a 25-year long warranty (also known as a performance guarantee). In most cases this means a guaranteed electrical production for 10 years at 90% of rated power output and 25 years at 80%.Rated power output (also known as the peak power rating, Wp) is the solar module`s DC maximum power output under Standard Test Conditions (STC) – solar irradiance of 1,000 W/m², solar spectrum of AM 1.5 and module temperature at 25°C. JA Solar, First Solar, Canadian Solar, Sanyo, Sharp and most other solar panel manufacturers uses this standard model of degradation in their warranties. However, some manufacturers set themselves apart from the competition by offering better performance guarantees:

SunPower has recently updated their warranty (April 1st, 2013) and guarantees 95% of rated power for the first 5 years, declining by no more than 0.4% per year the following 20 years.[1] This means SunPower guarantees 87% of rated power output at 25 years – by far the best warranty on the market.

Yingli Solar`s Panda solar panels guarantees 82% of rated power output at 25 years.[2]

SolarWorld and Trina use linear performance guarantees (see graph below).[3]

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To find out how much you could save, become a member for free today!';}?> 

Note that these are the best warranties these manufacturers offer (e.g. the guaranteed power output of Trina Solar`s polycrystalline solar panels are slightly lower than those that are based on monocrystalline). What happens after my warranty expires?We don`t really have a lot of data on what will happen to the performance of solar panels 30-40 years down the line. Chances are that your solar panels will keep generating a significant amount of electricity and bring in savings for many years after the warranty expires.For more information on solar panel life expectancy, go to Lifespan of Solar Panels.If you`re calculating how much power your solar panels will produce yourself, don`t forget to take into account that their output will decrease with time.//Retrieve session data

FinancingWhat is the best way to finance solar panels?

Solar Comparison Tools – EnergySage vs. 1BOG Solar Comparison Tools – EnergySage vs. One Block Off the Grid (1BOG)Last updated June 7, 2013 by Mathias Aarre Maehlum Leave a Comment

For the average homeowner, getting solar panels or not is a big decision that requires some serious thinking. Two companies have emerged on the market – EnergySage and 1BOG – and they both aim to simplify the process with their new solar comparison tools.The basic idea behind the two tools is the same: Homeowners receive quotes from qualified installers in their area and free guidance to find the best solution.This leads to a more competitive market and financial benefits for the homeowners, solar installers and financers, as well as market expansion and increased demand.The two companies have been compared to services like Orbitz, Expedia and Kayak, which you`re probably familiar with if you travel a lot.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> One Block Off the Grid1BOG was founded in 2008. In the beginning, the company aggregated homeowners in the same regions in order to leverage group discounts. Slowly but surely, the company has morphed into what it is today: A platform where homeowners can compare custom quotes from the biggest solar providers in the country. Pure Energies acquired 1BOG in 2012.[1]  EnergySageEnergySage was awarded $500,000 from the U.S. Department of Energy`s SunShot Initiative in 2012.[2]  Since then, the company has enlisted more than 1,600 installers, which ultimately means higher competition and better prices for homeowners.Both 1BOG and EnergySage have spent a lot of resources on developing solid educational content to teach homeowners about the various systems, how they work and how they can finance them. What are the Differences?1BOG and EnergySage almost looks identical on the surface, but in certain aspects they actually operate very differently from each other:

Solar installers can look for qualified homeowners at the EnergySage Marketplace and submit quotes. EnergySage receives a commission from installers that win a contract on a per-watt basis. 1BOG is more active in the “brokering” process, and matches homeowners and installers.

1BOG partners with major solar power installers and financers. Here are some of the big ones: SolarCity, SunRun, SunEdison, OneRoof Energy and Pure Energies. While 1BOG only focuses on major solar providers, EnergySage also allows minor installers onto their platform. It`s hard to say which model is more effective at this point.

EnergySage also helps homeowners with solar thermal, small wind, geothermal, biomass, biofuel and combined heat and power systems.

EnergySage is currently only in the Northeast and Colorado, while 1BOG have hosted deals in more than 40 U.S. states at this point.

Is 1BOG or EnergySage the better option for me? Try both! Both tools are free, without obligations and will only take you a couple of minutes to set up.

Best Way to Finance Solar Panels

Going solar can literally cost tens of thousands of dollars – not a lot of homeowners can afford to pay in cash. Luckily there are many good financing options. In this article, we`ll help you sort through them, and find which one would be the best choice in your situation.Contents

Solar Lease Power Purchase Agreement (PPA) Home Equity Loan Energy Efficient Mortgage (EEM) Property Assessed Clean Energy (PACE) Program Peer-to-Peer Lending Shared Solar Group Purchase

 Solar LeaseThe market for third-party-owned solar has exploded since SolarCity introduced solar leasing back in 2006. PV Solar Report found that more than 70% of Californians prefer third-party-owned solar (solar lease or PPA).[1] The same trend can be seen in many other states.More than 75% of all American households have access to third-party owned solarWith both solar leasing and PPAs (power purchase agreements), the solar provider pays for, and is the rightful owner of the solar system. They will take care of the system installation, and they are responsible for maintenance, monitoring and repairs. In return, they receive the financial incentives (including the federal 30% tax credit).You can lease (or sign a PPA) for little or no money down. With a solar lease, you simply pay the solar provider a pre-determined monthly amount; regardless of how much electricity the solar panels produce.The leasing fee is typically significantly lower than the price of electricity from your utility company.For more information on solar leasing, check out Best Solar Lease and PPA – SolarCity, SunRun, Sungevity, SunPower or Real Goods Solar?. Power Purchase Agreement (PPA)What is the difference between solar leases and power purchase agreements? A power purchase agreement is very similar to a solar lease, however, there is one key difference: You pay a pre-determined monthly amount for every kWh the solar system produce (as opposed to paying a monthly fee regardless of power production.)If I want to finance solar through third-party-ownership, should I choose a solar lease or a PPA? In many cases, this is determined by where you live and what utility company you`re connected to. Request a free solar consultation to learn about what options are available to you. Home Equity LoanWe generally recommend homeowners that can afford to pay a solar system in cash, or have access to a well-structured loan, to avoid third-party ownership.Financing solar through home equity loans, energy efficient mortgages or PACE programs will undoubtedly bring in more savings in the long run.To learn more about why you should avoid leasing (if you can) in Benefits of Owning (vs. Leasing) Solar Panels.

Many homeowners have financed their solar systems through loans in the past and many still do. However, the popularity of lending has decreased since third-party ownership appeared on the solar market.Home equity loans are essentially equity loans with your property as collateral.The borrower creates a lien against the home and reduces its equity.Depending on the structure of the loan, homeowners save more in electricity bills compare to their loan payments already from the start:

Interest rates range from 3.5-7.5%. Terms are typically 7-20 years. Interest may be tax deductible.

 Energy Efficient Mortgage (EEM)The federal government offers energy efficient mortgages that can be used to finance solar panels. An energy efficient mortgage credits a home’s energy efficiency in the mortgage itself.Your home needs to be home energy rated through a professional energy audit before financing is approved. Property Assessed Clean Energy (PACE) ProgramIn some states you can finance solar through a PACE program. The homeowner loans money from certain municipalities (city, town, county or state) and pays back through higher property taxes over 15 to 20 years.PACE programs do not reduce equity in your home. If you sell your home, the tax liability is simply transferred to the new owner. Terms typically last for 15-20 years and no credit check requiredAs with home equity loans, in many cases, electricity savings exceed loan payments from the start. Legislation for PACE programs have been processed and passed in 27 states across the U.S. Peer-to-Peer LendingPeer-to-peer lending is relatively new way of financing where borrowers and lenders are matched through crowdsourcing platforms such as Prosper and Lending Club.You are typically not required to use your property as collateral. On the other hand, interests rates are higher than those of home equity loans, which ultimately will yield a lower return on investment (less long term savings). Shared SolarMany homes are not suited for solar due to shading, structure and ownership issues. According to NREL, only 22 to 27% of residential rooftop area is a good fit for solar panels. [2] With shared solar, everyone have the opportunity to go solar.Shared solar can be both community- or third-party-owned. The finances can be structured in several ways. In most cases, the homeowner subscribes to shared solar and receive energy bill credits accordingly. Group PurchaseYou`ve probably heard of Groupon – an internet-based platform where people can sign up for offers together and unlock group discounts. One Block Off the Grid (1BOG) is using the same concept on the residential solar panel market. Homeowners typically save 10-20% with 1BOG`s financing programs. Find out how much you can save below:

How Much Solar Panels Cost

How much do solar panels really cost? This is undoubtedly the question we`re asked the most, and unfortunately it has no straightforward answer. We decided to pull together all aspects of this question, and write the best resource on the costs of solar panels you will find on the entire Internet.Residential solar systems are typically sized from 3 to 8kW and end up costing between $15,000 and $40,000. The cost per watt (price inclusive of parts, labor, permitting fees, overhead, and profit) has decreased significantly over the last decade and is now between 6 and 8 ($/W) in many parts of the U.S. Generally, the bigger the system, the lower the cost per watt.The total costs are split into system, installation and operational costs, roughly in the following ratios:Contents

Case Study System Costs Installation Costs Operational Costs Incentives Solar for $0 Down

 The goal of this article is to give you an idea of how much a solar panel system will end up costing in your particular situation.In the first part of this article we`ll be going through how much solar panels cost for a typical American single-family home. By clicking on the blue links in the overview table below, you will be taken further down on the page, to part two, for more in-depth information. Case StudyLet`s start by evaluating the solar system costs for a single-family home in Los Angeles, California. To make things simple, this family chose to pay for their solar system in cash – you`ll learn more about other ways to finance a solar system further down on the page.In order to supply 70% of the household`s electricity consumption, 5,600 kWh per year, we decided to install a 3 kW solar system on their roof.5,600 kWh is the equivalent to:

6,000 lbs. less in carbon emissions Planting trees on half an acre Not driving your car for 7,500 miles

 The calculations below are based on the following assumptions:

Electric bill of $100 per month Cost per watt at $6.50[1]

Electricity rate at 14.78 cents per kWh[2]

Annual growth of electricity rate at 2.8%[3]

These numbers are all based on recent data from credible sources – see reference list at the bottom. 

Costs

Total Costs $19,500

System $9,000

Solar Panels $6,500

Balance of System $2,500

Installation $7,500

Labor $3,000

Permits, Inspection Fees $4,500

Operational Costs $3,000

 Note that costs have been rounded to closest $500 in order to generalize the case study. 

Incentives $9,252

LADWP Solar Incentive Program $4,860

30% Federal Tax Credit $4,392

Net Costs $10,248

 Tax credits and other benefits that are received over time have not been evaluated. In other words, the homeowner would pay less in reality than what our calculation suggests. 

Savings

Total Savings $21,989

Net Present Value $2,919

Rate of Return (ROR) 11%

Payback Time 9.5 years

Return on Investment (ROI) 215%

Total Savings $21,989

Increased Property Value $16,720

 Total Savings represent the sum of electricity savings for the next 25 years – typically how long a solar panel warranty lasts. The solar system will more than likely keep generating electricity after 25 years, which will result in more savings and a higher ROI in the years to come. 

Above is an overview over how much the family from California saves every month for the first year. In the graph below, you can clearly see net savings from 1st to 30th year. The payback time is when the net savings reaches zero, about 10 years after initial investment.

 

Payback TimePayback time represents the threshold where savings have exceeded costs.The family from our case study has paid back their entire solar system after nine years and six months (see graph above).According to the U.S. Department of Energy, most solar systems pay for themselves within 5 years.[5] In some places in the United States, the payback time can be as little as three years.The electricity your solar system generates beyond this point brings in long-term savings. Residents in Hawaii saves on average $64,000 over the course of only 20 years. Increased Home ValueU.S. Department of Energy states that a solar electric system raises the property value of a home with $20 for every $1 in utility savings over a year.[5]

This means that the family with the 3kW solar system from our case study instantly added $16,720 to their home value by putting solar panels on their roof (based on the first year`s electricity savings of $836).What are some of the other ways you can benefit from going solar? Read our list over the most important Benefits of Solar Panels. System CostsAs mentioned in the introduction, residential solar systems are typically sized from 3 to 8kW and end up costing somewhere between $15,000 and $40,000. In this section, we will look at the costs of the various components of a solar system (not installation or operational costs).Note that all numbers discussed in this article are dependent on a boatload of different variables such as where in the country you live – they do however represent typical costs. Solar PanelsThe solar panels themselves usually account for about 30% of total costs. Residential solar panels with a combined capacity of 3-8kW typically cost between $4,000-$16,000.The best solar panels are not necessarily the most expensive. Cost per watt ($/W) is a more convenient way of looking at the costs of solar panels. This metric indicates costs relative to electrical power output. The cost of solar panels have decreased significantly over the last decade and are currently selling for under $0.70/W in industrial quantities. For homeowners, this translates to about $1.5/W.

 Balance of SystemBalance of system (BoS) refers to all components of a solar system except the solar panels themselves. This typically includes one or several inverters, mounts, wiring and other electrical components. Balance of system makes up for about 20% of total costs – homeowners should expect to pay somewhere between $3,000-$10,000 for these components. InverterInverters convert direct current (DC) from your solar panels into alternating current (AC), which is used by home appliances and enables you to grid-tie your system. Inverters typically account for 10% ($1,000-$4,000) of total costs.Also note that solar panels usually come with a warranty of 20-25 years, but conventional central inverters will need replacement before this.If you choose to go with micro-inverters instead of a central (string) inverter, the costs will increase along with a boost in power output and an extended warranty. Installation CostsIn this category we`ve included labor costs (15%), as well as permits and inspection fees (15%). The cost of both categories are highly dependent on what state you live in, but in most cases end up between $2,000-$5,000 per installation.Here`s a few things you might have to take into account:• Building and electrical permits at Department of Buildings• Neighborhood covenant requirements• Approval from homeowners association

 Your solar installer might not be educated on what is involved in obtaining the various permits where you live. Choosing a reputable and large installer is often the best choice.

Benefits of Owning (vs. Leasing) Solar Panels What are the benefits of purchasing a solar system vs. leasing one? In this article we will take an unbiased look at both options and help you, the homeowner, to get a better sense of what`s the better choice in your particular situation.It`s more than six years since SunRun introduced “zero-down” payment schemes for solar. Third-party ownership has turned out to be a complete game changer for the solar industry. The company recently announced a growth of 80% in California in only one year.[1] Another study revealed that more than 70% of Californians who go solar prefer third-party ownership.[2]Similar numbers can be found in other sunny states across the country as well. You save more money by buyingThere is more money to save (in the long run) if you purchase a solar system in cash. As the owner of the solar system, you receive all the rebates (in some areas up to $6,000 per kilowatt), the 30% tax credit and the additional SREC income that your new solar panels produce.Loaning is usually wiser than leasing. Most homeowners finance their solar panels through a home equity loan or a second mortgage. Many solar installers offer long-term financing at very affordable rates. If you were financing through a loan that is equivalent to a typical solar lease, you would be paying somewhere between 8-20% in interests (usually tax deductible).//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> Solar panels will increase your home valueHow much is the big question. Here`s a rough estimation to give you an idea of what quantities we`re talking about: A solar system that is producing $1,500 in annual savings with a prevailing fixed mortgage rate of 5% would increase your home value somewhere around $30,000 ($1,500/0.05).A study conducted by National Renewable Energy Laboratory (NREL) concluded that homes with solar panels sell 20% faster and for 17% more money.[3]  A lease is not an investmentI often advice people to look at purchasing a solar system as a long-term investment. I want to emphasize that a solar lease is not an investment – you do not have ownership of the solar system itself (you have no assets). A solar lease is a long-term year commitment to 10-20 years of lease payments. When would you financially commit yourself to rent a home for 10-20 years? Solar leases may reduce your home value

You will find leasing companies that advertise increased home value with their solar leases. In some cases this is true (homes with lower electricity bills tend to be worth more). However, a solar lease can also be a hindrance when you`re trying to sell your home. Finding a buyer that qualifies with excellent credit and agrees to assume your solar lease can be tough. Alternatively, paying yourself out of the lease can be very costly. No one knows where the prices are headedA lease can come with a fixed, escalating or de-escalating payment plan.You`re only saving money if the utility bill savings actually exceeds the lease payments. No one really knows where the electricity price is at ten years down the line. Likewise, no one knows what solar systems will cost in the future either.Understand that the feasibility of a solar lease is based on predictions about the future.Also worth mentioning is that the predicted future costs of electricity is dependent on where you live. SolarCity says, “utility rates increase 5% per year”, meanwhile, U.S. Energy Information Administration (EIA) predicts that electricity prices will slightly fall over the next decade due to a decline in natural gas prices.[4]  Solar leases make sense in some situationsGoing solar with a $0 down approach can be very tempting, and in some situations they make perfect sense.Here are some of the benefits of solar leases:

With a solar panel lease you can start saving money from day one. Performance is guaranteed. Maintenance, repairs and replacements are generally taken care of by the leasing

company. Inverters typically only come with a 10-year warranty and will eventually need

replacement. Solar leasing companies might be eligible for subsidies that homeowners do not have

access to. In what situations do these benefits outweigh a cut in long-term savings?

You want a solar system, but lack in cash or do not have access to a well-structured loan; solar leasing could be the way to go.

You do not have a high enough income, or you are a non-profit organization, and cannot take advantage of solar tax credits and deductions.

 Regardless of whether it’s the best possible deal, for many people wanting to let the sunshine in, it’s the only deal.

Best Solar Lease and PPA – SolarCity, SunRun, Sungevity, or SunPower? Third-party-owned solar has taken the residential market in the U.S. by storm. SunRun

recently announced a growth of 80% in California in only one year.[1]Another study revealed that more than 70% of Californians who go solar prefer third-party ownership.[2] Similar numbers can be found in several other states as well.

Many companies have started offering “zero-down” payment schemes since SolarCity first introduced the ingenious financing model back in 2006. Homeowners no longer have to pay heavy upfront costs to reap the benefits of solar photovoltaic panels.

We`ll take a closer look at the five largest leasing companies in the solar industry (SolarCity, SunRun, Sungevity, SunPower and Real Goods Solar). What are their differences? The goal of this article is to help you figure out which solar provider is the best choice in your situation.

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Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today! ';

}?>

  Let`s start with a quick overview over a few common terms: Solar Lease Leasing a solar system is pretty much the same as leasing a car or a TV. You pay your

solar provider a monthly fee (fixed, escalating or de-escalating) to lease their solar panels.

Many companies will allow homeowners to prepay the entire lease, or part of it (down payment).

  Power Purchase Agreement (PPA) Power purchase agreements are almost identical to solar leases – the only difference is

that you pay for the amount of power the solar panels produce, as opposed to just leasing the equipment.

What is common for both solar leases and PPAs is that most companies will take care of everything from installation to monitoring and maintenance. The duration of a solar lease/PPA is typically 10-20 years.

You might want to check out the following article for more information on the subject: Benefits of Owning (vs. Leasing) Solar Panels.

  Benefits Protection from rising electricity prices. Leases and PPAs provide protection against

volatile electricity prices. Top tier electricity prices have increased about 5% on average every year for the last 30 years.

Sit back and relax. The five solar companies that we discuss in this article take care of everything from start-to-finish – including installation, monitoring, maintenance and repairs. You will be provided with a performance guarantee, insurance and warranty.

Save from day 1. Solar leases and PPAs are comparable to, or in most cases, cheaper than their original utility bill. Solar has really become a no-brainer for many homeowners.

  The five solar providers offer different services:

SolarCity SunRun Sungevity SunPower RGS

Contract structure

PurchaseLeasePPA

LeasePPA

LeasePPA

PurchaseLeasePPA

PurchasePPA

Duration 20 years 20 years 10-20 10-20 20 years

of lease years years

Brand of solar panels

SanyoKyoceraSuntech

Depends on installer

Depends on installer

SunPower

SunPowerSolarWorldKyoceraCanadian Solar

  None of the companies are operating in all states. SolarCity offers their services in 12

different states. SunRun has recently expanded to Australia and the Netherlands.

SolarCity SunRun Sungevity SunPower RGS

Arizona

California

Colorado

Connecticut

Delaware

Hawaii

Maryland

Massachusetts

New Hampshire

New Jersey

New York

Oregon

Pennsylvania

Rhode Island

Texas

Vermont

SolarCity SunRun Sungevity SunPower RGS

Washington

  Whether or not you can finance your solar system through a lease or PPA is a function

of applicable state laws and your solar provider. In New Jersey for example, SunRun only offers PPAs while SolarCity offers lease as well.

  What are the differences between SolarCity, SunRun, Sungevity, SunPower and RGS? SunRun and Sungevity are “financing only” companies. They have partnerships with

local solar installers in the states where they operate in. SunPower manufactures their own solar panels and also handel financing. Only

authorized dealers can install SunPower solar panels. SolarCity is the only company that takes care of both financing and installation. The

company placed #10 on the World`s 50 Most Innovative Companies by Fast Company in 2012[3] :

“The key: Rather than just make panels, it is a full-service operation–designing, installing, financing, and maintaining every system. That’s how to ease new customers into an unfamiliar technology.”

  What’s the Catch? Solar leases and PPAs almost seem too good to be true. The solar provider is the owner

of the solar system if you choose a lease or PPA, and have the right to all incentives, rebates, refunds and cash credits (including SRECs).

The bottom line is this: It is true that a cash purchase would be cheaper in the long run, but most homeowners simply can`t afford the heavy upfront costs. SolarCity, SunRun, Sungevity, SunPower and Real Goods Solar are making solar possible for more homeowners, which not only is great for the environment, but can also help you bring in a lot of savings.

One Block Off the Grid has helped thousands of homeowners spend less by going solar. Become a member to find out which leasing company is best for you. It’s 100% free:

What`s the Difference Between Net Metering and Feed-In Tariffs?  Feed-in tariffs (FITs) and net metering, also known as net energy metering (NEM), are both methods designed to accelerate investments in renewable energy technologies (e.g. solar panels and wind turbines) by allowing energy producers (e.g. homeowners) to be compensated for the energy they feed back into the grid. Net MeteringMost electricity meters are bi-directional and can measure current flowing in two directions. This allows you to easily bank excess electricity from your solar panels for future credit. Net metering can be implemented easily without special equipment or any prior notification.Net metering only requires one power meter, while feed-in tariffs require two.Unlike feed-in tariffs and power purchase agreements, the credits you accumulate through net metering are always at full retail value.Net metering was first adopted by utilities in Idaho in 1980. Since the Energy Policy Act of 2005, every public electric utility is required to offer net metering to their customers. Some provinces in Canada have implemented net metering. 

Feed-In TariffFeed-in tariffs require one extra power meter in order to measure outflow of electricity from your home independently. This enables electricity consumption and electricity generation to be priced separately.Feed-in tariff schemes are typically based on a 15-20 yearlong contract where prices are pre-defined above retail with a tariff degression, which effectively reduces your earnings over time. For every kWh you generate you get paid.Unlike net metering, feed-in tariffs do require prior arrangement and notification.Only six states across the U.S. currently have some form of feed-in tariff scheme as of today: California, Florida, Vermont, Oregon, Maine and Hawaii.<sup[1]< sup="" style="box-sizing: border-box;"></sup[1]<>

 Virtual Net MeteringVirtual net metering is basically net metering (with one electric meter) shared between several people. This enables homeowners that are unsuited for solar for one reason or the other, to participate in community-owned solar farms (also known as solar gardens).There are about one dozen virtual net metering systems operating in the U.S. at the time of writing.Rules can vary significantly by country and state/province:

Is net metering or feed-in tariff available? How much are the credits worth (retail/wholesale)? How long can I actually keep my banked credits? Is there a monthly connection fee?

 

Extra ResourcesCrave more knowledge on solar energy? This section is for you:

Do I Really Need Solar Panel Batteries?

In off-grid situations, batteries make perfect sense. You want to store whatever excess electricity your solar panels generate for later use. Without batteries (or a connection to the utility grid), you would end up wasting a lot of electricity (and money)!

If you`re grid-tied, the situation is completely different. It doesn’t matter if you produce more electricity than what you`re capable of consuming. Excess electricity is simply put onto the utility grid (through net metering or feed-in tariff schemes). As a result, your power meter spins backwards, and you receive bill credits accordingly.

Learn more about the different types of solar systems here: Grid-Tied, Off-Grid and Hybrid Solar Systems.

  In one sense, the utility grid is really like a virtual battery. Tap it for energy during times

when your solar panels aren`t producing (e.g. cloudy days and nights), and recharge the battery when you`re producing too much.

Grid-tied solar panels can be combined with solar batteries for extra protection against utility grid blackouts. However, we still recommend backup generators over batteries due to obvious cost differences.

Solar batteries are expensive. A properly sized battery bank will typically cost you $5,000-$10,000. Also note that solar batteries should be replaced every 10 years.

The bottom line is this: Homeowners with a grid-connection should steer away from solar panel batteries. They simply do not need them. Only consider solar panel batteries if you`re in an off-grid situation.

Are Solar Panel Tracking Systems Really Necessary?

The sun`s trajectory is a factor of time of day, geographical location and season. The goal of all solar trackers (some more sophisticated than others) is to follow the sun`s trajectory and ensure that the solar panels are positioned for maximum exposure to sunlight.We seldom see solar trackers in residential applications. Are solar tracking systems really necessary for homeowners? Solar trackers significantly improve performanceThe companies that sell solar trackers are claiming an increase of 25-45% in power output compared to fixed-tilt solar systems (e.g. rooftop installations). No wonder why solar trackers were used in more than 85% of all commercial photovoltaic (PV) installations larger than 1MW between 2009 and 2012.Improved performance in terms of higher power output is another way of saying better space-efficiency.In one sense, a solar tracking system that improves efficiency by 30% would be the equivalent to solar panels with a 30% higher efficiency rating. Likewise, the same increase in performance can be obtained by making the system 30% larger (add more solar panels).SunPower says their T0 Tracker requires 20% less land than conventional crystalline fixed tilt systems and 60% less than thin film.[1]

 Which type of solar tracker is the best?

There are single and double-axis solar trackers. We typically see a performance gain of 25-35% with single-axis solar trackers. With double-axis solar trackers, performance goes up additionally 5-10%. With most single-axis trackers you can manually adjust a second axis on regular intervals throughout the year.We also separate between active and passive solar trackers. We have to feed active solar trackers with energy (i.e. electricity) because they are reliant on motors, gear trains or hydraulics. Passive solar trackers are based on compressed fluids with low boiling points, and run purely on solar energy, but are less accurate.Increased complexity inevitably introduces additional possibilities for malfunction and failure. For most homeowners, simplicity will yield the highest long-term savings. The extra performance gain of double-axis solar trackers is typically not worth it. Are solar trackers worth the extra costs and maintenance?In large-scale applications, regular maintenance is necessary for performance to stay consistent. Residential solar trackers generally require little maintenance, but failures occasionally happen.If you`ve got limited space, and you`re looking to make the most out of it, solar tracking could be wise. However, for most homeowners it all comes down to long-term savings. Does the performance gain from the solar trackers justify the additional costs? Maybe the money is better spent on extra solar panels? Don’t forget that most solar trackers consume power. There may also be local regulations that forbid the use of solar trackers.

What is Solar Energy? You probably know that solar energy is sunlight (solar radiation) that is constantly being

emitted from the sun. Where does this sunlight actually come from and what exactly is solar energy?

  Solar energy is nuclear fusion Solar radiation energy, sunlight, or insolation, are all words used to describe the total

spectrum of electromagnet energy that is emitted by the sun. A small fraction of this energy hits the Earth. The sunlight that hits the earth’s surface does not only include visible light, but also infrared and ultraviolet light. It takes about 8 minutes for sunlight travel from the sun to earth.

What does sunlight, nuclear reactors and atomic bombs all have in common?Nuclear reactions drive them all. Nuclear fission, which is the foundation of conventional nuclear reactors, is the name of the process where an atom is separated into two smaller atoms. Nuclear fusion is the process where two smaller atoms merge together, forming one larger atom.

The net mass before and after a fission or fusion process is negative; in other words, there is a loss of mass in a nuclear reaction. This mass does not just disappear, but is converted into energy.

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Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today! ';

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  Where does the energy in the sun come from? Nuclear fusion of hydrogen into helium.

In fact, the Sun fuses about 620 million metric tons (almost 1.4 billion pounds) of hydrogen into helium every second.

99% of the energy from nuclear fusion is generated inside 24% of the Sun’s radius, which flows outwards through several different layers, before it escapes as sunlight. A little further out, there is no nuclear fusion taking place at all.

  How long will the sun continue to shine? The sun has been burning for several billion years already. The continual loss of mass

caused by nuclear fusion means that the sun is slowly disappearing. But don’t worry; according to NASA the Sun has another 6.5 billion years worth of fusion processes left before it shuts down.

Learn more about the advantages and disadvantages of solar energy in the following article: Solar Energy Pros and Cons.

The History of Solar Energy – Timeline

The massive potential of solar energy is almost too hard to grasp, which is why harnessing this Sun’s energy for useful purposes has sparked the interest of many scientists for thousands of years. This article consists of a timeline over milestone historic events around human’s efforts to extract solar energy.Photovoltaics are devices that use what is known as the photovoltaic effect to generate electricity from sunlight. Knowledge around this phenomenon has only been around for about two centuries, which is why the history of solar cells (photovoltaics) begins in the middle of the article. 700 BC – Sunlit FiresWe know that all the way back to the 7th century B.C., humans figured out how to make fires by concentrating the sunlight with magnifying glass. 

214–212 B.C. – Archimedes’ Heat Ray

Historians claim that Archimedes, a Greek inventor, put solar energy to use already in the 3rd Century BC. He destroyed enemy ships with fire during the Siege of Syracuse with a “heat ray”, which supposedly was a collection of mirrors that concentrated sunlight onto the ships. Whether or not Archimedes’ invention has any root in reality is uncertain. Several experiments have been carried out to verify or bust the story, most of which concluded in the phenomena being possible, but highly unlikely.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> 1767 – The First Solar OvenA solar oven, or solar cooker, uses sunlight to heat meals or drinks. Today’s solar ovens are cheap and popular solutions to prepare meals in parts of the world where access to electricity is limited. These devices are only reliant on sunlight to work – there is no fuel required.Already in 1767, the first solar oven was invented. The credit goes to Horace de Saussure, a Swiss physicist, which probably had no idea his invention would help people prepare their dinner two and a half centuries into the future. 1839 – The Discovery of the Photovoltaic Effect1839 marks a big year in the history because Edmund Becquerel, a French physicist, only 19 years old at the time, discovered that there is a creation of voltage when a material is exposed to light. Little did he know, that his discovery would lay the foundation of solar power. 1873 – Photoconductivity in SeleniumWilloughby Smith, an English engineer, discovered photoconductivity in solid selenium. 1876 – Electricity from LightBuilding on Smith’s discovery three years before, professor William Grylls Adams, accompanied by his student, Richard Evans Day, were the first to observe an electrical current when a material was exposed to light. They used two electrodes onto a plate of selenium, and observed a tiny amount of electricity when the plate was exposed to light. 

1883 – The First Design of a Photovoltaic CellAn American inventor, Charles Fritts, was the first that came up with plans for how to make solar cells. His simple designs in the late 19th  century were based on selenium wafers. 1905 – Albert Einstein and the Photoelectric EffectAlbert Einstein is famous for a wide variety of scientific milestones, but most people are not aware of his paper on the photoelectric effect. He formulated the photon theory of light, which describes how light can “liberate” electrons on a metal surface. In 1921, 16 years after he submitted this paper, he was awarded the Nobel Prize for the scientific breakthroughs he had discovered. 1918 – Single-Crystal SiliconJan Czochralski, a Polish scientist, figured out a method to grow single-crystal silicon. His discoveries laid the foundation for solar cells based on silicon. 1954 – The Birth of PhotovoltaicsDavid Chapin, Calvin Fuller and Gerald Pearson of Bell Labs are credited with the world’s first photovoltaic cell (solar cell). In other words, these are the men that made the first device that converted sunlight into electrical power. They later pushed the conversion efficiency from 4% to 11%.I hope you enjoyed reading about the history of solar energy and photovoltaics. If you miss any key events on this timeline, use the comment section below and we’ll make sure to add them as soon as possible.

Where is Solar Power Used the Most? Solar power remains, after hydro and wind, the third most important renewable energy

source in terms of globally installed capacity. In 2012, more than 100 GW of solar photovoltaic (PV) power was installed in the world — an amount capable of producing at least 110 TWh of electricity every year. [1]

  What countries have the highest installed capacity of solar PV power? The table below is based on data from EPIA`s annual Global Market Outlook (2013).[1]

Ranking Country Installed PV [MW]

1 Germany 32,411

2 Italy 16,361

3 China 8,300

4 USA 7,777

5 Japan 6,914

6 Spain 5,166

7 France 4,003

Ranking Country Installed PV [MW]

8 Belgium 2,650

9 Australia 2,650

10 Czech Republic 2,072

  Where are the solar energy resources located? Solar energy exists in abundance all over the globe, but not every place would be

suitable for solar PV panels, solar thermal collectors or other means of converting sunlight into useful energy.

“Where in the world is the potential of solar energy the greatest?” would be a better question. A world insolation map is the best answer:

The solar radiation (insolation) map is based on values from Meteonorm.[2]

Warmer colors indicate higher solar energy density (insolation, solar radiation, sunlight). As you can see from the map, insolation tends to be higher the closer we get to the equator.

  Solar incentives play a huge part in market development Many of the countries in the world that have the highest capacities of installed solar

power do not necessarily have high levels of insolation. Incentives (government and state subsidies) play a major role in making solar power affordable.

  Germany is number one in the world Germany has by far the highest capacity of solar photovoltaic power (PV) in the world at

32,4 GW (31%) at the end of 2012.[1] Newly connected PV systems worth 7.6 GW were added this year.[1] Germany’s solar panels generated about 23 TWh (terawatt hours) of

electricity in 2012, which is impressive, but still only covers 3% of the country’s total electricity consumption. Market analysts believe this number will increase to 25% before 2050. Germany aims for a total capacity of 66 GW by 2030 with an annual growth of 2.5-3.5 GW.

Germany is not a country with incredible amounts of solar energy – what they do have is an excellent subsidizing framework, which ensures that solar power can compete on the market. With a well-developed feed-in tariff scheme, small and large-scale solar PV systems can send excess electricity production to the utility grid for profit.

  The rest of Europe is catching up Other countries in Europe have also started to implement similar incentives, and show

impressive numbers in terms of new growth: Italy added more than 3.4 GW of solar PV capacity in 2012. France, UK, Greece and

Bulgaria were not far behind. Spain has become the world leader in solar thermal power (CSP) with a capacity of 1

GW in 2012.[3] This represents 65 percent of the total installed CSP capacity in the world.[3]

  Solar leasing spurs growth in the U.S. The U.S. places number four on the list with a total solar PV capacity of 7,8 GW, right

behind China at 8,3 GW. The California Solar Initiative is at the forefront of the development. California, as of June 2013, has close to 1,6 GW of solar power.[5]

New Jersey, Arizona, Colorado and New Mexico are not far behind. We are seeing a lot of growth in the residential sector thanks to smart financial

programs. Solar leasing and power purchase agreements (third-party ownership) allows homeowners to go solar without upfront costs

Update June 2013: The U.S. now has over 8,500 MW in solar PV capacity, enough to power more than 1.3 million average American homes. [4]

What is the Potential of Solar Energy?

174 petawatts (PW) of energy comes in form of solar radiation (or insolation) hits our atmosphere. Almost one third of this is reflected back into space. The rest, 3 850 000 exajoules (EJ) every year, is absorbed by the atmosphere, clouds, oceans and land – one hour of insolation is the equivalent to more than the world’s energy consumption for an entire year.Solar energy is by far the largest energy resource on the Earth.Here are some other interesting comparisons to help make you grasp the massive potential of solar energy:

One year’s worth of solar energy reaching the surface of the Earth would be twice the amount of all non-renewable resources, including fossil fuels and nuclear uranium.

The solar energy that hits the Earth every second is equivalent to 4 trillion 100-watt light bulbs.

The solar energy that hits one square mile in a year is equivalent to 4 million barrels of oil.

In comparison, only 1% of the electricity consumption in the U.S. can be sourced back to the United States. This number is steadily growing and is expected to help replacing fossil fuels in the long run. Intermittent Energy SourceUnfortunately, far from the entire solar energy potential is exploitable. Solar is an intermittent energy source, which means that it is not available all the time – sunlight always hits the surface

of the Earth, but due to the fact that the Earth rotates around the Earth, solar energy is not available on one single location day and night.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?>Massive PotentialYou are probably wondering how big the potential of solar power is (converting solar energy into electricity). Estimating this potential largely depends on what factors are taken into account. It is important to realize that solar power isn’t feasible in many areas of the World due to low cost-competitiveness. Luckily, by the help of government and state incentive, costs are decreasing.Here’s an overview over how much area has to be covered in photovoltaics (solar cells) to cover the entire World’s energy consumption (based on an assumption of an electricity conversion rate of 8%):

Image credit: Wikimedia Commons

Solar Energy Pros and Cons Below you`ll find a list over the various pros and cons of solar energy. By clicking on one of the blue links, you will be taken further down on the page for more in-depth information. Everything you are about to read is properly referenced at the bottom.Pros

1. Renewable 2. Abundant 3. Sustainable 4. Environmentally Friendly 5. Good Availability 6. Reduces Electricity Costs 7. Many Applications 8. Shared Solar 9. Silent 10. Financial Support from Government/State

11. Low Maintenance 12. Technology is Improving

Cons1. Expensive 2. Intermittent 3. Energy Storage is Expensive 4. Associated with Pollution 5. Exotic Materials 6. Requires Space

      Advantages of Solar Energy1. RenewableSolar energy is a renewable energy source. This means that we cannot run out of solar energy, as opposed to non-renewable energy sources (e.g. fossil fuels, coal and nuclear).We will have access to solar energy for as long as the sun is alive – another 6.5 billion years according to NASA[1]. We have worse things to worry about; in fact, scientists have estimated that the sun itself will swallow Earth 5 billion years from now. 2. AbundantThe potential of solar energy is beyond imagination. The surface of the earth receives 120,000 terawatts of solar radiation (sunlight) – 20,000 times more power than what is needed to supply the entire world.[2]

 3. SustainableAn abundant and renewable energy source is also sustainable. Sustainable energy sources meet the needs of the present without compromising the ability of future generations to meet their needs. In other words, solar energy is sustainable because there is no way we can over-consume. 4. Environmentally FriendlyHarnessing solar energy does generally not cause pollution. However, there are emissions associated with the manufacturing, transportation and installation of solar power systems – almost nothing compared to most conventional energy sources. It is clear that solar energy reduces our dependence on non-renewable energy sources. This is an important step in fighting the climate crisis. 5. Good AvailabilitySolar energy is available all over the world. Not only the countries that are closest to the Equator can put solar energy to use – Germany, for example, has by far the highest capacity of solar power in the world. 6. Reduces Electricity CostsWith the introduction of net metering and feed-in tariff (FIT) schemes, homeowners can now “sell” excess electricity, or receive bill credits, during times when they produce more electricity than what they actually consume.

This means that homeowners can reduce their overall electricity expenses by going solar. Data from One Block Off the Grid reveals that adding solar panels to your home can bring in monthly savings of well above $100 in many states. In Hawaii, residents save on average $64,000 after 20 years!Nowadays, most homeowners choose leasing or power purchase agreements to finance their solar panels. This drastically reduces, or in some cases completely eliminates, the upfront costs of a solar panel system, and allows homeowners to start saving money from the first day.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?>If you want to learn more about the advantages specifically related to residential solar photovoltaic panels (generating electricity with solar energy at home), then check out Benefits of Solar Panels. 7. Many ApplicationsSolar energy can be used for many different purposes. It can be used to generate electricity in places that lack a grid connection, for distilling water in Africa, or even to power satellites in space.Solar power is also known as “The People`s Power”, which refers to how easily deployable solar panels are at the consumer level (both photovoltaic and solar thermal).With the introduction of flexible thin-film solar cells, solar power can even be seemingly integrated into the material of buildings (building integrated photovoltaics) – Sharp, a solar panel manufacturer with headquarters in Japan, recently introduced transparent solar power windows. 8. Shared SolarBecause of shading, insufficient space and ownership issues, 1/5 American homes are simply unfit for solar panels.[3] With the introduction of shared solar, homeowners can subscribe to “community solar gardens”, and generate solar electricity without actually having solar panels on their own rooftops. 9. SilentThere are no moving parts involved in most applications of solar power. There is no noise associated with photovoltaics. This compares favorable to certain other green-techs such as wind turbines. 10. Financial Support from Government/StateGovernment and state rebates have become available both on utility-scale and for the majority of homeowners. This means that the effective costs of solar panels are much less than what they used to be. In some cases, the price of a residential photovoltaic system can be cut more than 50%.As of 12/31/2008, the U.S. government offers a 30% tax credit with no upper limit. Chances are your home is also eligible for other grants and rebates.

Find out what applies to you by searching through the Database of State Incentives for Renewables & Efficiency (DSIRE) – or find out in minutes with our free guide How to Go Solar. 11. Low MaintenanceThe majority of today`s solar power systems do not required a lot of maintenance. Residential solar panels usually only require cleaning a couple of times a year. Serious solar manufacturers ship 20- or 25-year warranties with their solar panels. 12. Technology is ImprovingTechnological advancements are constantly being made in the solar power industry. Innovation in nanotechnology and quantum physics has the potential to triple the electrical output of solar panels. Disadvantages of Solar Energy1. ExpensiveIs solar power really expensive? This is probably the most debatable aspect on the entire solar energy pros and cons list. The driving forces behind the development of solar energy are rooted in politics. Solar power is incentivized to compete against other energy sources on the market. On the other hand, the U.S. government, similarly to the rest of the world, provides incentives to every major energy production market – not just solar.In 2010, coal received $1,189 billion in federal subsidies and support for electricity production while solar is not far behind at $968 billion.[4] Nowadays, the best solar panels can in many situations be cheaper than buying electricity from the utility. This wouldn`t have been possible without incentives. 2. IntermittentSolar energy is an intermittent energy source. Access to sunlight is limited at certain times (e.g. morning and night). Predicting overcast days can be difficult. This is why solar power is not our first choice when it comes to meeting the base load energy demand. However, solar power has fewer problems than wind power when it comes to intermittence. 3. Energy Storage is ExpensiveEnergy storage systems such as batteries will help smoothen out demand and load, making solar power more stable, but these technologies are also expensive.Luckily, there`s a good correspondence between our access to solar energy and human energy demand. Our electricity demand peaks in the middle of the day, which also happens to be the same time there`s a lot of sunlight! 4. Associated with PollutionWhile solar power certainly is less polluting than fossil fuels, some problems do exist. Some manufacturing processes are associated with greenhouse gas emissions. Nitrogen trifluroide and sulfur hexafluoride has been traced back to the production of solar panels. These are some of the most potent greenhouse gases and have many thousand times the impact on global warming compared to carbon dioxide. Transportation and installation of solar power systems can also indirectly cause pollution.The bottom line is this: There’s nothing that’s completely risk-free in the energy world, but solar power compares very favorably with all other technologies. 

5. Exotic MaterialsCertain solar cells require materials that are expensive and rare in nature. This is especially true for thin-film solar cells that are based on either cadmium telluride (CdTe) or copper indium gallium selenide (CIGS). 6. Requires SpacePower density, or watt per square meter (W/m²), is essential when looking at how much power can be derived from a certain area of real estate of an energy source. Low power density indicates that too much real estate is required to provide the power we demand at reasonably prices.The global mean power density for solar radiation is 170 W/m².[5]  This is more than any other renewable energy source, but not comparable to oil, gas and nuclear power.

5 Mind-Blowing Solar Energy Facts In this article, we’re taking a look at 5 interesting things about solar energy that you probably never have heard of. This will change the way you look at solar energy for the rest of your life. 1. Solar has Incredible PotentialIf we add the amount of solar energy that is absorbed by the Earth’s atmosphere, land and oceans every year, we end up with approximately 3,850,000 EJ (exajoules or 10^18 joules).To put it in more understandable terms, this amount of energy is equivalent to:

2.7 million earthquakes of the same size as the Tohoku earthquake in Japan (2011). 40 000 times the total energy consumption in the United States 8 000 times the total consumption in the whole world. About 40% of the energy that is required to heat the entire volume of water we have on

Earth by 1°CelsiusUnfortunately, harnessing all this energy is not achievable. Here’s an overview that illustrates the potential of solar power more realistically:

The sum of the tiny squares you see on the world-map is the area that is required to cover the entire energy consumption with solar power. 2. Is Solar Power Green?Let me get one thing clear: Solar power is certainly greener than conventional ways of harnessing energy sources such as fossil fuels and coal.On the other hand, there are issues regarding manufacturing of the solar panels, as well as disposal and recycling of byproducts. Where does the solar panel end up when it is no longer usable? (Most solar panels for home only have a warranty of 25 years).

Emissions of greenhouse gases do take place during the manufacturing. Dangerous climate gases such as nitrogen trifluoride and sulfur hexafluorideare both on the list. These literally have many thousand times the impact on global warming as an equal amount of carbon dioxide would. 3. Solar Powered Aircrafts!Yes, it’s true. NASA has been working on a series of solar powered unmanned aircraft since the 1980’s.  Pathfinder, Pathfinder Plus and Helios Prototype, is the result of NASA’s efforts to use solar power for long duration high altitude flights.

The Helios Prototype (above) reached a record altitude of 96 863 feet in late 2001, which is the highest altitude reached by an aircraft that is not powered by rockets for sustained horizontal flight.//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> 4. Solar Energy is Nuclear FusionNuclear power is a term we use to describe ways to harness energy throughnuclear fission and fusion processes. Conventional nuclear reactors rely on the fission of uranium atoms to produce heat, which we use to generate electricity. Nuclear fission processes releases vast amounts of heat, but is still far from the potential of fusion, the exact same phenomena that powers the Sun (as well as other stars).

Scientists are now working on what can be described as “the holy energy grail of energy”, or how to harness nuclear fusion, and they have been doing so for the last 70 years.If we are able to tame this power before we reach a century of scientific efforts is uncertain. What is certain is that once we reach this milestone, the way we harness energy will be revolutionized. We are no longer dependent on resources when it comes to energy. Terms like renewable and sustainability will become meaningless. We will move into a new paradigm whereknowledge = energy.Heavy hydrogen (also known as deuterium) that is extracted from not more than 1L seawater, can with nuclear fusion generate energy equivalent to what we find in 300 L petrol. 5. The Sun is Dying

You probably know that solar energy is considered a renewable energy source. The reason for this is that the electromagnetic radiation emitted from the Sun (also known as sunlight) will be around for us to harness, and will not disappear anytime soon:According to astrophysics, the Sun was born about 4.57 billion years ago and has another 6-7 billion years before it becomes a white dwarf (a planetary stage where nuclear fuel in the star is exhausted).Fortunately you don’t have to worry about this.  When the hydrogen reserves on the Sun are depleted, it will expand into a red giant, and will likely swallowing the Earth. Luckily we have another 5 billion years before this will happen!

Amorphous Silicon Solar Panels Amorphous silicon (a-Si or a-Si:H) solar cells belong to the category of silicon thin-film, where one or several layers of photovoltaic material are deposited onto a substrate.Some types of thin-film solar cells have a huge potential. These technologies are expected to grow rapidly in the coming years as they mature. In 2011, amorphous silicon solar cells represented about 3% of market.[1]

The word “amorphous” literally means shapeless. The silicon material is not structured or crystalized on a molecular level, as many other types of silicon-based solar cells are.

Most pocket calculators are powered by thin film solar cell made out of amorphous silicon. For a long time, the low power output of amorphous silicon solar cells limited their use to small applications only.This problem is partially solved by “stacking” several amorphous solar cells on top of each other, which increases their performance and makes them more space-efficient.In laboratory conditions, scientists have pushed efficiency rates to 12.5%.[1]The efficiency of amorphous silicon solar cells that are manufactured in high-volume processes ranges from 6% to 9%.[1] Oerelikon set the world record for stable amorphous solar cells to above 10% in 2009.[2]

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To find out how much you could save, become a member for free today!';}?> Advantages

Requires much less silicon. Amorphous silicon is a direct-bandgap material, and therefore only require about 1% of the silicon that would`ve been used to produce a crystalline-silicon based solar cell.

The substrates can be made out of inexpensive materials such as glass, stainless steel and plastic.

Theses are the two major reasons why amorphous silicon solar cells have a great potential to one day become cheaper than mono- and polycrystalline solar cells.

Can be made flexible and lightweight. A flexible thin-film module enables us be much more creative when it comes to applications. They can be placed on curved surfaces and will probably in the future be incorporated into clothing! Strength and flexibility is determined by the surfaces or substrates the thin film solar cells are attached to.

Thin-film solar cells perform relatively well under poor lighting conditions and are not affected as much by shading issues.

Amorphous silicon can be deposited onto substrates at temperatures below 300°C, which makes the technology a good candidate for flexible substrates and roll-to-roll manufacturing techniques.

 Disdvantages

Amorphous thin-film solar cells have lower efficiency rates. The technology is new, and efficiency rates are thought to increase with technological breakthroughs in the near future.

Thin-film solar panels tend to degrade faster and not last as long as mono- and polycrystalline solar panels.

You would have to cover a larger surface with amorphous silicon solar panels than crystalline-based solar panels for an equal output of electrical power.

 The bottom line is this: Amorphous silicon solar cells show a lot of promise. They are lighter, more flexible, and potentially less expensive to produce. On the other side, the technology has to mature to compete against mono- and polycrystalline solar.

References: [1] U.S. Department of Energy, [2] Oerlikon//Retrieve session data

Building a Passive Solar Home – 5 Best Design Strategies Passive building designs are different ways we can take advantage of solar thermal energy to enhance heating (and/or cooling) in a building and thereby reducing the need to use other energy sources for this purpose.The main goal of passive solar building designs is to reduce overall energy consumption. This usually means that we try to maximize the Sun’s to ability heat a building during the winter, but also enhance cooling in the summer. Passive Solar Fraction (PSF)A building’s passive solar fraction is a measure of how much of the heating the Sun is responsible for. A passive solar fraction of 15%, which is considered sustainable, means that the 15% of a building’s energy demand for heating is taken care of by the Sun.It is possible to achieve a passive solar fraction (PSF) of more than 75% in some parts of the U.S., but at what costs? Most people are not willing toThen there is the problem of retrofitting compared to building from scratch. Looking into retrofitting an old building to enhance passive solar fraction often offers excellent benefits and should not be overlooked, but the greatest gains are made early in the planning stages (unless you are willing to conduct serious changes for an old building).//Retrieve session data$country_code = $_SESSION['country_code'];if($country_code == 'US' || $country_code == 'CA' || $country_code == false){echo 'Our members spend an average of $1,217.63 less per year on electricity. That's including the cost of solar panels. 

To find out how much you could save, become a member for free today!';}?> Greenhouses are excellent examples of passive solar building designs. They are optimized to enhance solar heating and lighting with roofs and walls made of plastic or glass. As a result, plants can be grown in areas of the World where the outside climate wouldn’t allow them.However, a greenhouse would not exactly provide ideal conditions for a human being. Passive solar building designs for homes are vastly different and more complex than those for greenhouses. Let’s look at some of the best design strategies when building a passive solar home:

The orientation of a building is crucial. You want the rooms where you spend the majority of your time in (living room, kitchen etc.) to face the direction of the Sun. This will both enhance heating and natural sunlight.

Smart shading enables us to keep the sunlight from entering the house during the summer when we want cooling. The solar trajectory is much higher in this season. The image below illustrates this concept perfectly.

Good insulation stops heat flow in and out of the building and helps to regulate indoor temperatures.

Ventilation should also be a part of passive solar building designs.  A solar chimney can be used to help natural ventilation and reduce energy demand.

Thermal mass or heat storage is another important aspect of smart passive solar building designs. Implementing trombe walls, ventilated concrete floors and water walls are some of the common efforts to store heat from the day and slowly release it when the Sun isn’t shining. You want the thermal mass as close to the center of the building.

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How Solar Thermal Collectors Work The world of solar thermal collectors can be very confusing. Terms like active and

passive solar systems, low-, and high-temperature solar thermal collectors might seem daunting at first, but are in fact quite simple.

The goal of this article is to give you a brief overview over different types of solar thermal collectors, how these devices collect heat by absorbing sunlight, and from there, different ways we distribute and use this heat energy. Let’s start with the basics:

  All solar thermal collectors such all essentially built around one functionality: Converting sunlight into thermal energy (heat). Heat is an energy form that is both more

useful and easier to store. However, the design of different types of solar thermal collectors can be very different.

  The Difference Between Passive and Active Solar Solar thermal collectors can be both passive and active. Passive systems are by

definition not reliant on external sources of energy to function, but rather use natural convection to transport heat, which takes place when there are different temperatures within a fluid.

In more practical terms, this means that as the sunlight is being collected and heat is absorbed, hot water rises. We now have a natural movement or flow of water.

Other common uses of passive solar systems include geyser or bubble pumps, space heating, solar cookers and solar chimneys. There are two types of passive solar thermal collectors on the market:

Active solar technologies, as you guessed, do use external sources of energy to function, most often electrical pumps and valves that deals with the heat transportation.

Solar thermal collectors are usually classified as low-, medium- or high-temperature. Low- and medium-temperature solar thermal collectors are mostly used in residential and commercial buildings, while high-temperature solar thermal collectors are needed to generate electricity on the utility-scale. Here are some typical examples of each category:

 

Low-Temperature Solar Thermal Collectors The solar thermal collectors in the low-temperature category are usually based on very

simple designs, many of which fits into the passive category. They are often found in swimming pools, or other places where the temperature-demand is quite low – at least compared to the temperature that is required to generate electricity. Most of them are based on flat panel designs.

Heating, cooling and ventilation (HVAC) is another excellent use of low-temperature solar thermal collectors. Read Building a Passive Solar Home – 5 Best Design Strategies to learn more about how we can design a building to take advantage of sunlight.

  Medium-Temperature Solar Thermal Collectors These solar thermal collectors are slightly more complex, but are able to supply a higher

temperature. You often find medium-temperature solar thermal collectors being used to cover a building’s hot water demand (or parts of it). They can also be used to sustain a comfortable room temperature. As with low-temperature, medium-temperature solar thermal collectors are usually based on flat plate panels.

This is also the category where solar drying of fuels and food, solar cookers and solar distillation belongs.

Learn more about medium-temperature solar thermal collectors in the following article: (coming soon)

High-Temperature Solar Thermal Collectors High-temperature solar thermal collectors are of higher complexity and can usually be

found in concentrated solar power (CSP) plants, due to the high temperature requirement of generating electricity by the use of steam turbines.

Concentrated solar power plants can be based on solar thermal collectors of many different designs. Learn more about the designs of high-temperature solar thermal collectors, CSP plants, and how we convert solar thermal energy into electricity in the following article (coming soon):

How Solar Powered Distillation of Water Works

Solar powered distillation of water can be defined as measures to separate and extract clean water by vaporization. This can be particularly useful to turn seawater, brackish or even contaminated water into clean water safe for drinking.The history of solar powered water distillation started with Aristotle, already back in the 4th century BC, described a technique of solar powered water distillation.  However, it was not before late 19th century, that the first large scale solar water distillation plant was built. This plant, located in Chile, supplied as much as 20 000 liters of safe water to nearby inhabitants.

What is the difference between solar distillation and solar desalination?Before we get into how these processes work let’s take moment to clear any confusion around distillation and desalination. As mentioned above, solar distillation is separation of clean water by vaporization. Desalination refers to the process where salt and other minerals are removed from water. While heat is necessary for distillation of water, electrical or mechanical driven systems can use reverse osmosis to desalinate water. How Solar Water Distillation WorksDistillation of water with solar energy is quite simple. Think about how nature creates rain: The Sun heats and evaporates water, which at the same time is separated from salt, dirt or anything else for that matter. When the temperature and pressure is right, the water molecules reforms and returns to liquid. Regardless of where in the World you are located, if you catch rain before it hits the ground, it is considered safe to drink.Devices that are built around the concept of solar distillation all mimic the natural process of rain formation and can be described in two simple steps:

1. Evaporation to remove impurities.2. Condensation to collect the water.

 Different Still DesignsSingle-Basin Solar StillsA basin is covered by sloped glass or plastic where the evaporated water is condensed and lead into a rainwater channel. The darker the color of the basin, the more sunlight is turned into heat.The clean water output is higher in the evening due to greater temperature differences between warm water on the inside of the device and the outside ambient air.A stationary installation should be made out a glass basin to ensure longevity, but plastic would be better for a portable solar still.

 

Emergency StillsAn emergency solar distillation is essentially the same thing as the single-basin still described above except it is simpler.A mixing bowl can be used as the basin and plastic foil is put on top. A rubber holds the two together. Then a small stone is placed in the middle on top of the plastic foil and a cone shape forms. A cup and saltwater can be placed in the mixing bowl you have an emergency still. In case you don’t have a mixing bowl you can dig a pit to use as your basin. Multi-Stage Flash Distillation (MSF)This is where it gets a little bit more advanced. Multi-stage flash distillation (as well as multiple-effect distillation below) is used in larger scales where distillation plants are made to supply clean water for hundreds if not thousands of people.Multi-stage flash distillation is used to distill seawater by flashing water (lowering pressure to induce vaporization) in several stages. Distillation plants using multi-stage flash supplies 85% of all desalinated water worldwide. Multiple-Effect Distillation (MED)Another big one, as with multi-stage flash distillation above, multiple-effect distillation also consists of several stages (effects). Seawater is heated by steam in tubes, leading to partial evaporation and more steam in the next stage. The process is repeated several times. Every stage reuses some of the energy from the previous stages. Uses of Solar Water DistillationPeople Die from Unsafe Drinking WaterHumans can go weeks or even months without food, but just after a few days without water, chances of survival are getting slim. Water is absolutely essential. Most people take a supply of fresh and clean drinking water for granted, but in some places in the World or in emergency situations clean drinking water is not always readily available.World Health Organization (WHO) states that almost 1 billion people don’t have adequate access to water that is safe for drinking and that 2 million deaths are attributable to unsafe water, sanitation and hygiene every year.  Solar powered distillation of water can help to reduce these numbers. Cooking, Bathing and WashingThese are also common uses of solar-distilled water. By using solar distillation of water, people are less dependent on rainwater to supply all their needs. EmergencyAs mentioned with the solar emergency distillation stills above, solar distillation is a good way to provide water in emergency situations. In places where hurricanes are likely to strike, and electricity and water supplies can be cut, solar distillation can be lifesaving.Lifeboats are often equipped with solar stills. During the second world war, the U.S. Navy produced more than 200 000 inflatable solar stills for their lifeboats.

Why You Should Avoid DIY Solar Panels Building your own solar panel can be a fun and educational experience. However, there are a few things you should consider before you embark on a DIY solar panel project: Solar Panel Certification

The main drawback of DIY solar panels is that you need to have them certified.Having a solar panel UL listed takes several months and thousands of dollars. You run into a couple of major issues if your solar panel does not carry a UL mark:

You cannot legally grid-tie your solar system, which means net metering is out of the question.

You are probably violating your home insurance. Proper certification is required to reap in the benefits of state and federal incentives.

 There are also several other reasons why you should stick to pre-manufactured solar panels:

DIY solar panels are usually only suitable for small-scale electronics. The solar panel will typically degrade faster. Professional solar panels come with 25-

year performance guarantees. A poorly built solar panel can be a fire hazard. You should know what you`re doing if you

decide to go the DIY route.For more information on how you can install your solar panels, check outCan I Install Solar Panels Myself? Beware of ScamsThere`s a lot of shady companies around that want to sell you their DIY solar panel kits. Some of the people behind these products are not experts on solar panels, but experts on Internet marketing. Look out for their highly questionable marketing tactics – Eliminating your electricity bill for under $200 is simply not possible. If something seems to good to be true, it probably is.