Alternative energy that is renewable is energy that can be used repeatedly without depleting natural resources. The alternatives available, sometimes referred to as sustainable energy, are derived from natural sources and include energy powered by the sun, water, wind, and earth. Solar, hydroelectric, wind, and geothermal power are examples of renewable alternative energy sources.
There are two basic methods for capturing solar energy: passive and active. Passive solar collects energy without the use of any devices, such as solar panels. Passive solar energy is demonstrated by south-facing windows that help to illuminate and heat a home. Another way to use passive solar energy is to design a home with brick walls and tile floors to absorb heat and reduce heating costs.
Solar collectors are used to absorb energy from active solar energy. Solar panels, or photovoltaic arrays, are commonly used to collect solar energy, which is then converted into electricity. Batteries can be used to store this energy for later use. Solar energy has the disadvantage of being reliant on the sun, as it cannot be collected at night.
Hydroelectric power generates electricity by harnessing the energy of falling water. Dams are built to build up pressure in the body of water behind them, known as a reservoir, in order to use water as a renewable alternative energy source. When water is released from the reservoir, it falls onto the turbine’s blades, which causes it to spin.
The kinetic energy created by the water pressure and spinning turbine is converted into electricity by a generator connected to the turbine. The disadvantage of hydroelectric power is that it necessitates flooding a large area of land in order to construct the dam. This has the potential to displacing human communities and wildlife in the area upstream.
Wind power is another form of renewable alternative energy that, like hydroelectric power, uses turbines to generate kinetic energy, which is then converted into electricity by the wind. These turbines are similar to windmills in that they operate on the same principle. The disadvantage is that a wind power system can only generate electricity when the wind is blowing.
The heat or thermal energy generated at the earth’s core is used in geothermal energy systems. A geothermal heat pump converts heat into electricity and is installed several feet beneath the earth’s surface. The fact that some areas don’t have large enough reserves of thermal energy beneath the surface that can be accessed using heat pump technology is a disadvantage of this type of renewable alternative energy. As a result, geothermal energy isn’t available everywhere.