Different energy sources provide us with the energy we require to live and work. They include wind, solar, geothermal, and biomass sources. These sources are not just a major source for electricity, but can also be used to heat and transport. These energy sources produce greenhouse gases when they are used to generate electricity. This creates a need for more environmentally sustainable energy sources.
Fossil fuels are the most common form of energy. They include oil, coal and natural gas. They were formed millions of years ago when prehistoric plants and animals died and were buried under layers of sedimentary rock. Then, under the appropriate conditions, they gradually converted to carbon-rich substances which, when burned create energy. These fossil fuels are not renewable since they will be exhausted in our lifetimes or even in a number of lifetimes.
Renewable energy sources however are continuously replenished. The sun is the primary source of renewable energy since it supplies light and heat. We utilize it for our homes as well as for businesses and automobiles. Wind is another renewable energy source that produces electricity by spinning turbines. Since the first time people realized how to harness the wind in the past, we have been using it for millennia. We utilize biological processes to create an ethanol (a alcohol-like substance that is clear and transparent which can be used as fuel) from crops and waste.
Among these sources hydropower is by far the most important renewable energy source in the United States, though wind and biofuels are expected to become the dominant source in the near future. Hydropower is based on nature’s water cycle to harness the power of rapid-flowing water, which is then used in turn to produce electricity.