Three of the largest wind farms are located in southern and central California. The wind energy produced in California provides residents millions of kilowatt-hours of electricity every year. The nation's largest turbine in Michigan, consisting only of propellers, a gearbox, and a generator, saves 600 tons of coal a year. Wind farms can generate electricity for as low as 4 to 7 per kilowatt-hour. Geothermal Deep beneath the earth's surface, hot magma heats the underlying water or steam converting it to electricity.
Geothermal resources vary in temperature.
Geothermal plants are very economical and have minimal environmental impacts as well as produce only one-sixth of the carbon dioxide that a natural gas fueled electrical generating power plant produces. This clean, renewable, and indigenous energy uses two methods to convert biomass to electricity. Solid biomass fuels are burned in a broiler. The fuel turns to steam which is then used to turn a turbine generator to produce electricity. The second method involves gasifying the fuels to be burned and used as electricity.