Renewable energy is a term for any energy source that doesn’t require any raw materials, and generally also used as a bridge term for sources that don’t emit any green house gases. Renewable energy can replenish itself over and over again which is understood as “infinite” energy since it does not rely on finite resources.
Wind energy, solar photovoltaics and solar thermal, and hydro are great examples of renewable power being used today. The technical process by which renewable power is created is different depending on the specific natural resource that’s exploited.
Wind power is renewable as the only input required is rotor blades driven by wind energy, driving an electromagnetic generator to produce electricity. Hydroelectric energy uses gravitational forces of water trapped then released from a dam; water is trapped then diverted through turbines and spinning generators.
Solar photovoltaic energy is a major renewable power source, using a different method than the generator-turning method used in wind and hydro. Solar cells convert sunlight into electricity through a chemical process; sunlight is conducted in the form of photons, making silicon cells unstable, which creates an electrical charge.
Currently, solar photovoltaics are becoming more of a common trend, but are still well behind hydro. Solar and hydro are characteristically different renewable power methods; due to massive infrastructure requirements, hydro is mainly only used on large scale projects, initiated by governments, councils, and large power utility companies. Solar, with a relatively new popularity, works on both large and small scales – meaning the method can be used for utility facilities as well as small scale domestic systems.
The significance of renewable energy can be viewed within broad political, economic, social, and environmental contexts. Renewable energy engineering is primarily being driven by the need to move away from foreign energy dependence and the accompanying political tensions. Environmentally, we now know a lot more about the environmental impact of fossil fuel energy – local pollution as well as the effect of green house gases on global warming and there is a lot of renewable energy information available online.
Similarly to alleviating dependence on foreign supplies, renewable energy is presenting an option for developing and isolated areas where delivering reliable electricity has previously been challenging, expensive, or impossible. Locally-sourced renewable energy production can be achieved on a utility scale or by individual home and business owners installing small scale wind or solar systems.