We require a variety of energy sources to live and work. Solar, wind, geothermal and biomass are a few of the sources. These sources are not only an important source of electricity, but they can also be used to heat or transport. These energy sources emit greenhouse gases when they are burned to create electricity. This means that there is a need for greener sources of energy.

Fossil fuels are the most common type of energy. They include oil, coal and natural gas. They were created millions of years ago when prehistoric animals and plants died and were then buried under layers of sedimentary rocks. Under the right conditions the fossil fuels gradually transformed into carbon-rich compounds which, when ignited, produce energy. These fossil fuels will not be renewable as they will end up being depleted in our lifetimes, or in many lives.

Renewable energy sources are continuously replenished. The sun is the primary source of renewable energy since it provides warmth and light. We use it to power our homes vehicles, businesses, and homes. Wind is renewable energy source that produces electricity by spinning turbines. We have used it since humans first discovered how to harvest the wind for millennia. We use biological processes to create an ethanol (a clear, alcohol-like substance which can be used as fuel) from waste and crops.

Among these sources hydropower is the biggest renewable energy source in the United States, though wind and biofuels are expected be the next to take over. Hydropower relies on wikipedia reference nature’s water cycle to harness the power of fast-flowing water, which is then used in turn to generate electricity.