The five main AE forms are:
- Hydropower- the mechanical energy of moving water,
which can be used to spin a turbine connected to an electric generator
to produce
electricity;
- Biomass- organic material of plant and animal origin,
such as wood and municipal solid waste. When burned biomass releases
its chemical
energy as heat. It can also be converted to other usable forms, such as
methane gas, ethanol and biodiesel.
- Geothermal- the heat from within the Earth. It can
used to heat buildings or generate electricity at steam-turbine plants.
- Solar power-
the electromagnetic radiation from the sun that can be converted to
heat, electricity or chemical energy.
Except for probably hydropower, all these sources and particularly
solar and wind power can be used in private homes, especially if the
house is located in a rural area. For more information see
Solar
Power for Homes and
Wind
Generators.
PROS AND CONS
Each source of power generation has pros and cons and has a certain
impact on the environment.
AE emit less air pollution than conventional fuels. Utilization of AE
reduces US dependence on foreign oil, which would also reduce the flow of money
to totalitarian and terrorism-sponsoring regimes of some oil producers. However, our
reliance on fuel imports can also be lessen by relaxing
restrictions on the drilling that would let us tap our own large oil
and gas resources, provided it is done in an environmentally safe way.
The main
disadvantages
of AE are their higher cost and the difficulties to produce the large
quantities of electricity the conventional fuels are able to.
Currently almost half of the electricity produced in US uses coal. The
cost of generating electricity from coal is about $0.05 per
kilowatt-hour-- lower than that from any other sources. For comparison,
the cost to produce utility-scale solar electricity is $0.19/kW-hr. As
the result of the reliance on coal, US enjoys one of the lowest
electricity rates in the world.
The Penn State University study
showed that hundreds of billion dollars of household income and 6.8
million U.S. jobs will be attributed to the production, transportation
and jobs in energy consuming industries that rely on low-cost
electricity. The combustion of coal does produce carbon dioxide
emissions blamed for global warming, but these emissions can be
captured by using so-called clean coal technologies that are being
developed throughout the world. In short, the strategy for developing
environmentally clean power should focus on keeping its costs
affordable.
