Renewable energy generation is the production of electricity from naturally replenishing resources. Sunlight, water currents, wind and underground heat are all possible sources of renewable energy. Different mechanisms exist for extracting power from each of these resources.
These types of renewable energy resources are often a cheaper alternative to non-renewable sources, such as fossil fuels. They are often preferred because they are in limitless supply and have a no damaging effect on the environment. The technology needed to produce sufficient amounts of renewable energy, however, is still being developed in many countries.
Solar power from the sun's heat and light can be harnessed for renewable energy generation. It is the most widely applied form of replenishing power and is commonly generated in two ways. One is through the use of photovoltaic (PV) cells, which are thin layers of silicon that can transform sunlight into electrons and generate electricity. These are often made into panels that are installed on buildings. Another way to capture the solar power is through solar-thermal technology, which captures heat from the sun to produce steam that powers electric generators.
Hydro, or water, power generation has been used by people for a long time. In the past, farmers often used rivers to turn the waterwheels in mills. Today, power is typically generated from the water in dams and reservoirs. This usually involved the use of pipes that direct water flow onto turbines, which are rotating engines that create energy. Generally, a stronger water current will generate more electricity, because the turbine will turn faster.
Renewable energy generation can also be accomplished by harnessing the power of wind. Some of the most widely used devices for this purpose are wind turbines. Often shaped like mills, these usually have large propellers that produce electricity when turned by the wind. These turbines are usually erected in groups, called wind farms, and targeted to sections of the land that traditionally receive a lot of wind.
Biomass energy is generated by biological organisms, like plants, trees and bacteria. It has a variety of different uses, many of which benefit farmers. Bacteria in animal waste can be mixed with straw and water to produce manure, which helps fertilize the land. Methane gas can be produced from burning manure, which may be used for cooking. Alternatively, many people simply burn wood for heating.
Geothermal energy, or that created by heat from inside the Earth, can also be used for renewable energy generation. Often specially designed power plants convert this heat into electricity. Geothermal wells, which release hot greenhouse gases trapped inside the Earth, may be used to make heat or electricity. In some cases, hot underground water is used to heat individual homes. The problem with this type of energy is that, although it is cheap to produce, it is often insufficient and found at select locations.