2. Definition: Green or Alternative energy refers to the use of power that is not only more efficient than fossil fuel but that is friendly to the environment. Green energy is generally defined as energy sources that don’t pollute and are renewable.
3. Types: There are several categories of green energy. They are anaerobic digestion, wind power, geothermal power, hydropower on a small scale, biomass power, solar power and wave power.
4. Photovoltaic or Solar cells are made from silicon and absorb the sun's radiation. The Process involves the displacement and movement of electrons to absorb the sun's radiation and create electricity, Solar systems can also use large scale mirrors to heat water, or produce high temperature steam which is then used to turn generators.
5. Geothermal Geothermal power is cost effective, reliable, sustainable, and environmentally friendly. Geothermal energy uses trapped underground heat to make hot water or steam. The steam is then used to turn steam turbines which generate electricity. One of the few drawbacks of geothermal is it can only be located in areas near tectonic plate boundaries.
6. Hydropower The energy of water is abundant, Approximately 75 percent of all renewable energy is from Hydropower according to the Energy Information Administration EIA. Hydropower is generated by using the mechanical energy of flowing water to turn a generator to produce electricity. Hydropower can also come from wave and tidal flows in the worlds oceans
