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Renewable energy explained Types & usages

What are the different types of renewable energy?

Biomass energy—Biomass energy is produced from nonfossilized plant materials. Wood and wood waste are the largest sources of biomass energy in the United States, followed by biofuels and municipal solid waste.

  • Wood—Wood biomass includes wood pellets; wood chips from forestry operations; residues from lumber, pulp/paper, and furniture mills; and fuel wood for space heating and cooking. The largest single source of wood energy is black liquor, a residue of pulp, paper, and paperboard production.
  • Biofuels—Biofuels include ethanol and biodiesel. Most of the fuel ethanol used in the United States is produced from corn. Biodiesel is made from grain oils and animal fats.
  • Municipal solid waste and biogas—Municipal solid waste (MSW), or garbage, contains biomass (or biogenic) materials such as paper, cardboard, food scraps, grass clippings, leaves, wood, leather products, 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.
logs

Wood is our second-largest source of renewable energy

Source: Stock photography (copyrighted)

wind farm

A wind farm

Source: Stock photography (copyrighted)

Hydropower—Hydropower is electricity produced from flowing water. Most hydropower produced in the United States is from large facilities built by the federal government, such as the Grand Coulee Dam on the Columbia River in Washington state—the largest single U.S. electric power facility. 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.

Geothermal energy—Geothermal energy is heat from the hot interior of the earth or near the earth's surface. Fissures in the earth's crust allow water, heated by geothermal energy, to rise naturally to the surface at hot springs and geysers. Wells drilled into the earth allow a controlled release of steam or water to the surface to power steam turbines 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.

Wind energy—Wind turbines use blades to collect the wind's kinetic energy. Wind flows over the blades creating lift, which causes the blades to turn. The blades are connected to a drive shaft that turns an electric generator, which produces electricity.

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

  • Solar thermal 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. This fluid generates steam to power a turbine and a generator.
  • Photovoltaic (PV) systems use solar electric cells that convert solar radiation directly into electricity. Individual PV cells are arranged into modules (panels) of varying electricity-producing capacities. PV systems range from single PV cells for powering calculators to large power plants with hundreds of modules to generate large amounts of electricity.

Last updated: December 19, 2018