Renewable energy technology was created to offset the global reliance on non-renewable resources like natural gas, coal, and oil. It uses naturally occurring and replenishing processes to provide sources of energy that will never be depleted. Renewable energy technology most commonly refers to seven different energy sources, including solar, geothermal, and hydroelectric.
This technology is an attempt to solve problems with fossil fuels, such as its dwindling supply and environmental consequences. Purveyors of renewable energy technology look to the natural forces at work in and on the Earth. These processes, being part of the Earth's natural order, are sustainable for human consumption and not harmful to the environment.
Solar energy is derived from sunlight and is a very versatile renewable energy technology. It can be converted directly to usable energy via solar cells and stored to provide power to buildings. It can also act as a substitute for fossil fuels in power plants, where it is used to boil water, which drives a turbine and creates electricity.
Another renewable energy technology utilizes the force of the wind to generate power. Wind turbines are mounted atop a tall spire. When the wind passes the turbine's blades, the blades turn, moving the turbine and producing electricity.
Geothermal renewable energy technology uses heat transmitted from the Earth's core through its crust to either provide direct heating or to generate electricity through a power plant. Pockets of geothermal heated water can be found beneath the Earth's surface, and power plants can use the steam and heat from these to provide electricity. Geothermal energy has the potential to utilize the heat from rock 3 to 5 miles (4.8 to 8 km) beneath the surface of the Earth and possibly heat from magma, the most desirable source of geothermal energy.
The Earth's oceans act as gigantic solar collectors that trap heat in their upper layers. The great difference in temperature between the upper and lower levels of the ocean produces thermal energy. This energy is present in all of the Earth's oceans and can be used to accomplish many processes, including the production of electricity through thermal energy powered turbines in power plants.
Hydroelectric renewable energy technology uses the force of river or lake waters to produce electricity. The water is usually kept behind a dam and formed into a reservoir. The water from the reservoir is allowed to pass through the dam in a slow and steady manner that will turn the turbines housed within and generate power.
Biological renewable energy technology, also referred to as bioenergy, provides energy through the naturally occurring biological processes that take place in a number of sources. Parts of organic waste, residues, and plants can be converted into biofuels, biopower, and bioproducts. When plants grow, they remove carbon dioxide from the air. This process is considered to offset the carbon dioxide that bioenergy technology produces.
Hydrogen-based renewable energy technology uses the element hydrogen, found in many molecules and compounds, to produce power. Hydrogen fuel cells are capable of providing heat and electricity, and the only byproduct it releases is water, which can be recycled for human consumption and needs. Hydrogen fuel cells can be applied in many different fields, including powering automobiles and transportation devices.