Renewable energy is more than just a buzz phrase.
What is renewable energy? Renewable energy, sometimes called green energy, refers to sources of energy that have a much lower impact on the environment than do traditional energy sources. They're called renewable because they'll never run out, unlike finite conventional energy sources, such as fossil fuels. Other benefits of renewable energy, according to the National Renewable Energy Laboratory (NREL) and the Department of Energy (DOE), include less dependence on imported oil and the potential for economic activity from the domestic production of energy.
What are specific renewable energy sources? Renewable energy sources include the following.
- Solar. Radiant energy produced by the sun, consisting of light and heat, is called solar energy. When most people think of renewable energy, they think of solar. Harnessing the energy of the sun currently takes the form of photovoltaic panels and solar thermal collectors, commonly called solar panels.
- Wind. You won't confuse the futuristic looking windmills used for harnessing wind power with the traditional windmills found on farms, although the concept is the same. According to the DOE, at the end of 2010, there was enough wind power being generated to serve more than 9.65 million homes.
- Hydropower. Anyone who's been surfing or enjoyed a day frolicking in ocean waves understands how much power can be generated by water. Hydropower is the largest renewable energy source in the United States, and American companies continue to find ways to harness energy from waves, tides and currents.
- Biomass. Bioenergy is the energy derived from plants or plant-derived materials. You probably used bioenergy the last time you went camping as you sat around the campfire feeling the heat created from burning wood. Other biomass fuels, according to the NREL, include food crops, grassy and woody plants, residues from agriculture or forestry, oil-rich algae, and the organic component of municipal and industrial wastes.
- Geothermal. Anyone who's visited Yellowstone National Park and watched Old Faithful erupt has witnessed geothermal energy, or energy derived from the heat contained within the earth. Geothermal power can be used to generate electric power.
- Hydrogen and fuel cells. Fuel cells combine hydrogen and oxygen to produce electricity, heat and water. These fuel cells work much in the same way as a battery, but as long as hydrogen is supplied, the cells will never lose their charge.
As renewable energy sources continue to be developed, traditional sources, such as coal, oil and nuclear energy, that pose environmental risks will become less necessary.