Currently,
those living in the United States rely heavily on coal, oil, and natural gas
for their energy needs. But these sources of energy are nonrenewable. Fossil
fuels draw on finite natural resources that will eventually dwindle and become
unaffordable. Renewable energy resources, by contrast, such as wind and solar
energy, are constantly replenished. These sources of energy will never run out.
Most renewable energy sources come either directly or indirectly from the sun. Solar energy from sunlight can directly heat and light buildings. This direct energy use is referred to as Passive Solar Energy. Electricity generated from the sun with the use of photovoltaic panels is Active Solar Energy. Wind turbines capture energy from the wind the sun’s heating the atmosphere creates. The winds and solar heat create the water cycle. Energy can be captured from water using hydroelectric power.
The organic matter that exists because of the sun is known as biomass and can produce electricity, transportation fuels, or chemicals. Hydrogen, the most abundant element on the Earth, also can be found in many organic compounds. Once separated from other elements, hydrogen can be burned as a fuel or converted into electricity.
But, not all renewable energy resources come from the sun. Geothermal energy taps the Earth's internal heat for a variety of uses, including electric power production, and the heating and cooling of buildings. Energy is also produced from the ocean's tides. In addition to tidal energy, energy is derived from the ocean's waves.