Renewable Energy Resources

D8 - Describe the availability, current uses and environmental issues related to the use of fossil and nuclear fuels to produce electricity.

D9 - Describe the availability, current uses and environmental issues related to the use of hydrogen fuel cells, wind and solar energy to produce electricity.

D25 - Explain how land development, transportation options and consumption of resources may affect the environment.

D26 - Describe human efforts to reduce the consumption of raw materials and improve air and water quality.

D8 D9 D25 D26

Many of our current energy sources are causing pollution

43% of energy in the US is wasted unnecessarily

The problems ….

Example 1… lighting choices

Example 2… Automobiles

Changes in required mpg fuel efficiency would help to reduce gasoline consumption

Minimum requirements by date1974 – 12.9 mpg2014 - 29 mpg 2016 – 35.5 mpg

http://www.google.com/url?sa=i&rct=j&q=automobile+efficiency+standards&source=images&cd=&cad=rja&docid=VVX97J5v6Y_eWM&tbnid=AhyMew80KpGqwM:&ved=0CAUQjRw&url=http://www.nytimes.com/2012/08/29/business/energy-environment/obama-unveils-tighter-fuel-efficiency-standards.html&ei=bkqmUcPVE8ix0QH5jYDwBQ&bvm=bv.47008514,d.dmg&psig=AFQjCNHbumyNgB23nsdzbzquC6rQaYSakg&ust=1369938904822909

Efficiencies – these percentages show how much of energy taken in is actually used for the designated purpose

Some Ways to Improve Energy Efficiency

Insulate / Eliminate air leaks in homes / install high efficiency lighting

Insulate / Eliminate air leaks in homes / install high efficiency lighting

Purchasing more efficient appliances

Purchasing more efficient appliances

Build efficient electric motorsBuild efficient electric motors Increasing fuel economy

for all combustion engines Increasing fuel economy

for all combustion engines

Characteristics of Renewable Resources

A Renewable Resource:• Replenishes very

rapidly• Is in inexhaustible

supply

1. Solar—passive and active2. Hydroelectric power3. Wind generation4. Biomass5. Hydrogen Fuel Cell Power6. Geothermal

Renewable Energy Resources

Solar energy originates as energy derived from the sun in the form of solar radiation.

This energy can be captured in passive or active systems (see image below).

Using Solar Energy to Provide Heat and Electricity

PROS Fairly high energy acquisition, even on cloudy

days Quick installation No CO2 emissions / low environmental impact Installed system lasts 20-40 years

CONS Needs access to sun Low efficiency Requires an electricity storage system Expensive

Solar Energy

HydropowerHydropower is a method of producing electricity by harvesting the energy of moving water

Hydropower is a method of producing electricity by harvesting the energy of moving water

Currently, this supplies …50% of West Coast electricity7% of US electricity20% of World’s electricity

PROS More environmentally friendly than fossil

fuels and Reliable, stable and high efficiency Does not create waste

CONS High construction costs Major environmental impacts

Hydropower Pros and Cons

Environmental Effects of Hydropower

Pollution Pollution

Disruption of water flow

Disruption of water flow

Loss of biodiversity

Loss of biodiversity

Invasive species Invasive species

Producing Electricity from Wind

Wind energy is a form of energy conversion in which turbines convert the kinetic energy of wind into mechanical or electrical energy that can be used for power.

Historically, wind power in the form of windmills has been used for centuries for such tasks as grinding grain and pumping water.

Pros:◦ Reduces greenhouse gas emissions◦ All the turbines need to be able to function is wind◦ It will also foster domestic economic growth.

Cons:◦ Land must be taken from its current uses to

construct these turbines.◦ Wind energy is not always consistent◦ Blades of the turbines have in the past incidentally

kill birds that get caught in their path.◦ Turbines require maintenance

Pros and Cons of Wind Power

Biomass energy is energy derived from plants or plant-derived materials. Biomass can be converted into biofuels for transportation, biopower for heat and electricity and bioproducts for making things such as plastics.

Examples of biomass energy sources include wood, ethanol derived from grains and methane gas emitted from landfills.

Producing Energy from Biomass

Pros: 1. Renewable - We will always have the sources of biomass

such as crops, manure and garbage. 2. Carbon Neutral – The carbon in biomass is already part of

the carbon cycle, so this does not add more carbon to the cycle. 3. Cost-Effective - Energy harnessed from biomass is

inexpensive compared to coal and oil. 4. Abundant - Biomass is available over the world.

Cons: 1. Expensive - Extraction of biomasses can be expensive. In

some areas, biomass projects may not be worth the price. 2. Requires Space - Big areas are needed for all the different

processes that are required in harnessing energy from biomass.

Pros and Cons of Biomass

A hydrogen fuel cell uses the chemical energy of hydrogen to cleanly and efficiently produce electricity with water and heat as byproducts.

Currently, this technology is being applied to automobiles

Hydrogen Fuel Cell Power

PROS Less greenhouse emissions and lowered air

pollution Reduced oil dependence

CONS Expensive Fuel cell systems are not yet as reliable as

internal combustion engines There is not yet infrastructure in place to get

hydrogen to consumers

Hydrogen Fuel Cell Power

This term comes from the Greek roots geo, meaning earth, and thermos, meaning heat.

This energy comes from heat inside the Earth's crust. It's clean and sustainable

Geothermal Energy

Pros:◦ 1. Environmentally Friendly - There are a few polluting aspects of

harnessing geothermal energy◦ 2. Renewable - Geothermal reservoirs come from natural resources and are

naturally replenished. Geothermal reservoirs will literally last billions of years.

◦ 3. Massive Potential - Worldwide energy consumption – about 15 terawatts (TW) – is not anywhere near the amount of energy stored in earth.

◦ 4. Stable - Geothermal energy is a reliable source of energy. We can predict the power output of a geothermal power plant with remarkable accuracy.

Cons:◦ 1. Environmental Issues - There is an abundance of greenhouse gases

below the surface of the earth that can be released.◦ 2. Surface Instability (Earthquakes) - Construction of geothermal power

plants can affect the stability of land. ◦ 3. Expensive - The exploration and drilling of new reservoirs come with a

steep price tag (typically half the costs).◦ 4. Location Specific - Good geothermal reservoirs are not present in every

location.

Pros and Cons of Geothermal Energy

Geothermal Reservoirs

Our current system involves producing energy in large quantities at a few locations and moving it long distances.

A “decentralized micropower” system involved producing energy at more numerous smaller plants closer to where it will be used

Entering the Age of Decentralized Micropower

Fig. 16-39p. 411

Increase fuel efficiency standards for vehicle, appliances, buildings

Create tax and other financial incentives for energy efficiency

Subsidize renewable energy use, research and development

Internalize externalities for fossil fuels By 2050:

◦ Increase renewable energy to 50%◦ Cut coal use by 50%◦ Phase out nuclear altogether

Creating a Sustainable Energy Future

Solutions: A Sustainable Energy Strategy