'Renewable energy' is energy obtained from sources that essentially are inexhaustible, UNLIKE fossil fuels, for example, of which there are finite supplies. The non-profit Center for Resource Solutions, the main group responsible for auditing and oversight of the green power industry, considers the following types of electrical generation renewable energy: wind, solar, geothermal, biomass, landfill gas, and small hydroelectric (30 megawatts capacity or less).