Renewable energy is defined as energy created from a renewable and sustainable source. Not just wind turbines, water wheels and solar power, there are other sources, such as geothermal energy and biomass, which can be converted into useful energy.
As the world population is becoming increasingly concerned with the amount of fossil fuels being consumed and their effect on the environment, more and more people are looking to use renewable energy sources. They are usually locally sourced which has less of an impact on the environment. At home, using these sources allows people to save money and reduce their carbon footprint.
Wind power is the conversion of wind energy into useful energy usually using wind turbines commonly at sea. One of the most traditional and primitive forms of wind power is the windmill and ship sails. Wind farms at sea are useful as there is always wind, can be widely distributed, there are no greenhouse emissions and uses little land. The turbines are however very costly in construction and maintenance.
Solar Power is the harnessing of energy created by the sun’s radiation. This is usually done through capturing the radiation from the sun and converting it into electricity using silicon cells in solar panels. Solar power is used to power many every day items as well as heat houses and water. It is reliable, environmentally friendly, cheap to maintain and can be widely distributed. The conversion of sun to energy ratio however is low, and requires a large area of panels to absorb sufficient energy.
Water power (or hydropower) is the conversion of moving water into useful energy. Due to its denseness even a slow moving stream can generate a useful amount of energy. Watermills have been used traditionally to drive mechanisms for hundreds of years but these days technology has created hydraulic power pipe networks and compressed air hydro, which involves pressurising water to create mechanical energy. Hydraulic dams are also used, where the energy of the dammed water is driven through a turbine. Hydraulic plants have a long lifetime and are cheap to power, they have low greenhouse emissions and reservoirs created can also be used for other activities such as water sports. However, a major disadvantage is that often the construction of dams destroys local ecosystems and can cause flooding in the area upstream. Sediment can also build up in the area of dams.
Geothermal energy is the energy that is stored and generated in the earth. It comes from the original formation of the planet, and the radioactive decay of minerals. The core of the earth can reach 5,000 °C (9,000 °F). Extreme high pressure and temperatures causes the rock to melt creating magma and this forces its way up which heats rock and water on the crust, creating hot springs. Geothermal energy is reliable, environmentally friendly, and sustainable; however, it does no occur everywhere.
All of these sources have their advantages and disadvantages and are all valuable in their own right. Developing technologies will ensure that usage of renewable energy sources will become increasingly used over traditional burning of fossil fuels.