Renewable energy is that which can be constantly replenished. This is energy that is produced through sun, wind, water and other geothermal and biomass sources. Renewable sources can greatly vary in their cost and availability. These sources themselves are non-polluting, but the structures used for them can have both positive and negative effects on the environment.
The top five renewable energy sources are wind, solar, geothermal, biomass and water/hydropower.
WindMainly used to generate electricity. This form of renewable energy uses wind turbines to create energy. The blades to of the turbine collect the kinetic energy of the wind and then cause an electric generator to turn. This simple process creates electricity. New technologies have reduced the cost of using this method over the years. The wind machines do, however, require a large amount of land and the turbine itself can be quite expensive. While many electric companies are adding wind machines, it is not practical to use this as a sole source of energy. Wind is perpetual, but the amount of energy created is dependent on the current weather conditions.
SolarEnergy from the sun and is used to supply heat and electricity. Solar energy can be converted to thermal energy to heat structures and fluids. With the use of solar cells, or panels, the solar energy can be converted into electricity. Solar Thermal/Electric Power Plants also convert the solar energy to steam which can then be turned into electricity. Like wind power, the cost of solar energy has greatly reduced over the last few years. However, solar energy is only available if the sun is out. Once the sun sets, a reserve storage is required. So often, another source of energy is required.
GeothermalGenerated in the Earth’s core. Geothermal energy is used for heating and electricity. To extract this energy, a large well must be dug and the underground water or steam is pumped to the surface. Geothermal energy is practically unlimited and will be around for a very long time. Using geothermal energy is also more affordable compared to most other energy sources. The only drawbacks to this energy is that there is a very large initial cost for set-up, the facilities are normally set up around faults where earthquakes could possibly occur and they require a large amount of land.
BiomassGenerated through organic material, such as wood, crops or manure. The chemical energy in biomass is released as heat when it is burned. In addition, biomass can be converted to create types of fuel. This is a very clean form of energy and is relatively inexpensive. However, on the down side, using this energy depletes the Earth of necessary nutrients in the soil.
Water or Hydropower This form of energy is the most used renewable energy in the United States. Hydropower is converted to energy by building a dam and hydroelectricity facility. This is another environmentally friendly renewable energy. The cost of hydropower can also be significantly less than by using a non-renewable energy source. However, the cost of set-up and disruption of wildlife are both drawbacks to using this source.