In the US, electricity is mainly generated in power plants using steam turbines using a range of sources. In 2016, over 4 trillion kilowatthours of electricity was generated. Fossil fuels accounted for 65% of the power, with natural gas providing 34% of the electricity, coal producing 30% and petroleum less than 1%. Nuclear power plants were responsible for producing 20% of the US electricity generation.
Renewable resources provided 15% of the remaining generation, a slight increase of the past few years. The availability of renewable resources can vary due to fluctuations in rain, meltwaters, and daily and seasonal pattern changes. Of the remaining 15% electricity generation, renewables contributed to the power generation as follows:
Total Contribution to US Electricity Generation
Total Renewables Contribution to US Electricity Generation
Hydropower produces energy as flowing water spins turbines that are connected to generators. While many of the hydropower facilities are large federal facilities in western US, there are facilities throughout the country. Wind power has increased significantly over the past 4 decades. Biomass includes a variety of sources such as wood and wood product derivatives, landfill gas, biogenic municipal solid waste, or other waste biomass that can be either burned directly in steam-electric power plants or are converted to a gas and burned in a variety of generators. Solar power sources include either photovoltaic (PV) or solar thermal power. PV power produces electricity directly from sunlight, whereas solar thermal power generators use solar energy to heat a fluid for steam to run turbines. Heat beneath the earth’s surface provides energy for steam-turbines to produce geothermal power.