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Energy Basics

Visit the U.S. Energy Information Administration Energy Kids website and the Climate Literacy and Energy Awareness Network for energy-related games and activities, educational resources for teachers, and energy basics information.

The United States currently relies heavily on coal, oil, and natural gas for its energy. Fossil fuels are nonrenewable, that is, they draw on finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. In contrast, renewable energy resources—such as wind and solar energy—are constantly replenished and will never run out.

A photo of the solar array on top of the NREL Parking Facility.


Most renewable energy comes either directly or indirectly from the sun. Sunlight, or solar energy, can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot water heating, solar cooling, and a variety of commercial and industrial uses.

A photo of wind turbines at NRELs National Wind Technology Center.


The sun's heat also drives the winds, whose energy is captured with wind turbines. The Earth's rotation also contributes to the winds, particularly through the Coriolis effect.

A photo of an NREL Researcher holding a vial of algae co-products in the Algal Research Lab.


Along with the rain and snow, sunlight causes plants to grow. The organic matter that makes up those plants is known as biomass. Biomass can be used to produce electricity, transportation fuels, or chemicals. The use of biomass for any of these purposes is called biomass energy.

A geothermal power plant in California.


Not all renewable energy resources come from the sun. Geothermal energy taps the Earth's internal heat for a variety of uses, including electric power production and the heating and cooling of buildings.

A photo of a fuel cell vehicle at NREL.


Hydrogen can be found in many organic compounds, as well as water. It's the most abundant element on the Earth. Because energy is always needed to produce hydrogen, it is not an energy source, but a way to store and transport energy, so it is referred to as an energy carrier.

Yellow floating wave energy point absorber measuring marine hydrokinetics.


The ocean can produce thermal energy from the sun's heat and mechanical energy from the tides and waves. See the U.S. Department of Energy's website for information on marine and hydrokinetic energy technologies.

A photo of a hydropower system test.


Flowing water creates energy that can be captured and turned into electricity. This is called hydroelectric power or hydropower. For more information on hydroelectric power, see the hydropower basics from the U.S. Department of Energy's Water Power Program.