Renewable energy explained Types & usages

There are five main types of renewable energy

Biomass energy—Biomass energy is produced from nonfossilized plant materials. There are three main types of biomass energy:

• Biofuels—Biofuels include ethanol, biodiesel. renewable diesel, and other biofuels. Biofuels are mostly used as transportation fuels in the United States, and ethanol accounts for the largest share of total U.S. biofuel consumption.
• Municipal solid waste and biogas—Municipal solid waste (MSW), or garbage, contains biomass (or biogenic) materials and nonbiomass combustible materials (mainly plastics and other synthetic materials made from petroleum). MSW is burned in waste-to-energy plants to generate electricity. Many landfills in the United States collect and burn biogas to produce electricity.
• Wood—Wood biomass includes:
  • residues from forestry operations and lumber, paper, and furniture mills for use as industrial process heat and to generate electricity
  • fuel wood and wood pellets for space heating and cooking in homes and businesses

Geothermal energy—Geothermal energy is heat from the hot interior of the earth or near the earth's surface. Geothermal energy from deep underground is used to generate electricity. The near-constant temperature of the earth near the earth's surface is used in geothermal heat pumps for heating and cooling buildings.

Hydropower—Hydropower is electricity produced from flowing water. Most hydropower produced in the United States is from large facilities built by the federal government. There are two general types of hydropower:

• Conventional hydropower uses water in dams or flowing in streams and rivers to spin a turbine and generate electricity.
• Pumped-storage systems use and generate electricity by moving water between two reservoirs at different elevations.

Solar energy—Solar energy systems use radiation from the sun to produce heat and electricity. There are three basic categories of solar energy systems:

• Photovoltaic (PV) systems use solar-electric cells that convert solar radiation directly into electricity for powering small devices or generating electricity in solar power plants.
• Solar thermal heating systems use solar collectors to absorb solar radiation to heat water or air for space heating and water heating.
• Solar thermal power plants use concentrating solar collectors to focus the sun's rays to heat a fluid to a high temperature for generating electricity.

Wind energy—Wind energy is converted to electricity with wind turbines that are usually grouped together in wind farms. Most U.S. windfarms are in the Central region of the country. There are plans to develop wind energy projects in offshore areas of the United States.

Last updated: August 14, 2023.