Wind power does not produce air emissions, generate solid waste, or use water. Biomass is energy from trees and plants. This includes crops that are grown specifically for energy production and organic wastes, such as wood residues from paper mills and methane from landfills. Using biomass to generate electricity reduces global warming emissions if new plants are grown to replace those that are harvested. Geothermal energy uses heat from inside the earth to make clean power.
Solar power captures the heat and light of the sun to generate electricity.
Solar energy does not produce air emissions, generate solid waste, or use water. Hydroelectric power captures the energy in falling water. It does not produce emissions or solid waste, but can have a relatively low or high impact on the environment, depending on the site-specific factors such as maintenance of water flow and water quality, fish impacts, and other land use issues. Choosing new, green power could make a big difference for the environment, because electricity generation is the largest industrial polluter in the country. Electricity generation currently produces about two-thirds of the annual US emissions of sulfur dioxide, the main cause of acid rain and of very small soot particles.