What you must know Green Power KnowArticles by James Copper Green energy is the use of power, which is not only much more efficient than fossil fuels, but that is environmentally friendly as nicely. Green energy is generally referred to as energy sources that pollute and are renewable've defined. There are several categories of green electricity. They are anaerobic digestion, wind, geothermal, tiny hydro, biomass, solar and hydro. Waste incineration can even be a source of green energy.