Chapter 11 - Energy

11.1 Fossil Fuels to Energy

electricity -

- to generate electricity, electrons need to be in motion. - most common way to do this is to move an electrically conductive material through a magnetic field (silver is a good conductor but the most common is copper)- when many copper wires can be moved through a large magnetic field large amounts of electricity can be generated

electric generator -

- most of the energy that is converted to mechanical energy comes from

Basic Concept of Electricity Generation

- some form of fuel is used to boil water and create steam.- steam is directed through a turbine which in turn spins an electric generator- regardless of the way the turbine is made to turn, most forms of electricity are created by spinning an electric generator

11.2 Nuclear Energy

How Nuclear Energy Works

nuclear energy - energy that exists within the nucleus of an atom

nuclear fission - the breaking apart of subatomic particles, releasing huge amounts of energy

- the atomic bomb is an example of nuclear fission, in this case the atomic explosion may continue on releasing enormous amounts of energy- if the explosion is allowed to continue it will get out of control rapidly and will continue until all nuclear material that can be split is used up- in a nuclear power plant, the nuclear reactions are controlled and occur at a slow pace- regardless of the pace, huge amounts of energy is released which is used to boil water and create steam which spins an electric generator- for safety the reactor core (where the nuclear reaction takes place) and the boiler are in a containment building which usually are made of reinforced concrete that is meters thick

Nuclear Power - Pros

- extremely energy rich - 1 gram of uranium - 235 (235U) contains the same amount of energy as 3.5 metric tons of coal!- some reactors can run for years without the need to refuel or shut down for any reason except routine maintenance- does not produce carbon dioxide, many fossil fuel poor countries use nuclear energy extensive

Nuclear Power - Cons

- radioactive waste, each nuclear power plant has its own temporary storage but there is no facility for permanent storage of nuclear waste- nuclear fuel isn't in abundant supply, estimates vary between 100 and 200 years of available supply- plants are extremely expensive to build and minor problems may cause lengthy and expensive shutdowns

Safety Concerns- if the reaction gets out of control it can destroy the reactor building and put radioactive products into the air

Some examples of nuclear power plants have made headlines around the world and have caused much fear about the safety of nuclear power- 1957, a nuclear plant in the Ural Mountains of the former Soviet Union had an accidents but details are unknown- 1986, a plant in Chernobyl exploded after many of the plant's safety devices were shut off during a test.- the radioactive material contaminated several thousands of square kilometers of land, killed hundreds of firefighters and workers and probably caused cancer in many more- the plant in Chernobyl was an obsolete model and the explosion was caused by human error and human ignorance

United States

- 1979, a nuclear power plant at Three Mile Island in Pennsylvannia suffered a serious explosion- only a small amount of waste escaped - human error and broken equipment were believed to be the cause- the result was that the Nuclear Regulatory Commission required that over 300 safety improvements be made to existing and new nuclear power plants

11.3 A Sustainable Energy Future

1. Energy ConservationList 8 things you can do to conserve energy

2. Solar Energy

passive solar heating is - - have windows that - made of - can be kept warm with only energy

solar water heating - sun heats up liquid (water or antifreeze) which is pumped through a heat exchanger- the liquid heats the water used in the building

solar cells - panels capture the energy from sunlight and store it in cells which can be converted to electricity- it is costly, dependent on available sunlight and is limited in its storage limits

3. Wind Energy- cost of wind-generated energy is lower than the cost of some forms of electricity generation- the down sides are that there are a limited number of regions that can provide effective wind levels- some people find wind generators to be unattractive and noisy- the blades of wind generators can also interfere with microwave communications

4. Hydroelectricity- water is used to turn turbines which spin a generator

Advantages - clean and renewable- dams control flooding- the reservoir can supply a source of recreational activities and sometimes drinking water

Disadvantages - can cause problems to the ecosystem- cost of construction has increased significantly- very few good areas left

5. Geothermal Energy- heat that is stored inside the earth, sometimes relatively close to the surface- the heat can be used to turn turbines similar to regular power plants- downside is that the earth replaces the heat slowly- excessive use can deplete the source, one example is in the textbook

6. Biomass - organic matter in plants or plant products- basically wood is considered a form of biomass- downside is that the burning of biomass produces carbon dioxide and smoke- a large amount of biomass is actually waste material- biomass is considered to be carbon neutral- some industries use their waste material to generate their own electricity, wood pellets are an example of waste material that can be used for heat energy

7. Liquid Fuels from Biomass- methanol and ethanol are fuels that are derived from plants- methanol is derived from wood and ethanol from plants such as sugar cane, corn, fruit or other agricultural waste- both are cleaner burning than gasoline or diesel- a combination of ethanol and gasoline is becoming popular in certain places, in Brazil over half of the cars on the road are powered by ethanol/gasoline combinations- E85 is a common gasoline alternative used in the United States and is mostly derived from corn there- the downside is that there is great concern about using the corn to make the ethanol because it is being taken away from something else

8. Hydrogen- hydrogen holds great potential as a way to reduce emissions in vehicles as the product of combustionis water- there has been significant research in the use of hydrogen as a fuel- the major problems are storage, in order to store hydrogen it must be compressed and the size of the storage must be large, to hold enough hydrogen to travel any distance- the problems with the storage is the size, and the pressure, if the storage cell is pressurized enough it may exceed the pressure capabilities of the tank- on the other hand it can be chilled to low temperatures but in order to chill it you would need to use electricity which in most situations is generated by fossil fuels. Many of the pollution benefits of burning hydrogen will be nullified by the chilling process.- another problem is that hydrogen is difficult to transport to fueling stations due to its propensity for leakage- hydrogen is also very flammable and burns with an invisible flame, issues that create major concern

Where are we heading?

- in order to reduce greenhouse gas emissions we, as a global society, must reduce our reliance on fossil fuels- many of the ways have been listed on the previous page, so where are other places going?

1. Solar- as energy concerns grow more buildings are being built with the concept of passive solar heating- solar water heating is also gaining popularity, on average 1/3 of a home energy bill is spent on heating water so why not?- photo voltaic cells (solar cells) are dropping in cost, it is expected that solar generated electricity could be cost effective by 2010- the average house requires around 1500 Watts of power to run, solar panels average in size between 80 and 160 Watts, so with around 10 panels and an invertor some houses could be almost self sufficient

2. Wind- although North America has been slow to embrace it some places have decided to take a firm grip on wind power

- Denmark jumped in early when the cost of wind power far exceeded fossil fuel power- the Danish government supported the plans and today 21% of the country's electricity is generated by wind power and they are considered as the world leader in wind power production and building of turbines- the other benefit has been that over 85% of the wind power generators are owned by private individuals or wind co-ops- in the US it is estimated that wind could ultimately supply 20% of their energy requirements and the cost of generating wind energy is expected to continue to decrease- the main knock against wind turbines has also been that the wind doesn't blow all the time- in the UK it is estimated that wind turbines only generate at 28% of their capacity through the year wheras Nuclear (70%) and coal (50%) are somewhat higher but wind turbines are generally considered more reliable and definitely have the pollution advantage- birds, unsightliness and noise

Imagine building a house that is built on the passive solar heating principle which has solar hot water heating and a small wind power generator! Some places sell electicity back to the power companies.

3. Hydroelectricity- there are some small companies currently building small electicity generators that run on the water flow in a stream- the day of big dams are likely over though

4. Nuclear- as discussed nuclear power doesn't generated any greenhouse gases which is our major world goal right now but the public fear over safety, bombs and disposal of waste loom large- nuclear power plants generate huge power, around 1700 Megawatts and the cost is comparable to wind as far as price per unit- due to safety it can take almost ten years to get all the required approvals and construction itself can take another 5 years- as such no new reactors have been built in either the UK or the US in the last 20 years- some countries rely on nuclear heavily UK(25%), Sweden (50%) and France (80%) are good examples but it is expected that overall nuclear power will drop on the overall scale from around 18% currently to about 10% within the next decade.

- some countries are currently building reactors though- India, Russia, Japan and Canada have plants in the works and China has commissioned 2 plants per year for the next 20 years!- several other countries have approvals for 37 more generators in the near future* Chernobyl (pg 274)

*storage in Yucca Mountain, Nevada

*cost of dismantling nuclear power plant (p. 275

5. Geothermal - underdeveloped, today only about 10 000 megawatts are generarated by this method around the world- one nuclear or coal power plant can generate around 1700 megawatts- most locations were near volcanic activity and there is plenty of superheated water- the problem is that most of the water is used up quickly, leaving inadequate pressure- operators attempted to solve the problem by pumping water down into the ground but due to the rock formations being fractured, the water usually just disappeared- geologists have discovered one in Australia which may be able to provide all of their power needs for 75 years

Assignment - Storage of Nuclear Waste Pg 328, 329 Due

Write it as a letter to the editor

Left Side of the Room1. State why you support Yucca mountain as a storage site.

Right Side of the Room2. State why you are against Yucca mountain as a storage site for nuclear waste.

Also include some information about the status of Yucca Mountain today. (Cite yoursources)

Sample start

I am writing this letter in response to the use of Yucca Mountain in as a potential storage site of....