Renewable energy
different resources
Solar
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.
Wind
The sun's heat also drives the winds, whose energy is captured with wind turbines. Then, the winds
and the sun's heat cause water to evaporate. When this water vapor turns into rain or snow and flows
downhill into rivers or streams, its energy can be captured using hydropower.
Biomass
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.
Geothermal
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. And the energy of the ocean's
tides comes from the gravitational pull of the moon and the sun upon the Earth.
Ocean
The ocean can produce thermal energy as the sun heats the surface of the ocean and the lower layers stay cool.
Oceans provide a tremendous amount of mechanical energy from the tides and waves. These are caused by the effects
of the gravitational forces exerted by the moon, the sun and the rotation of the earth.
Hydropower
Flowing water creates energy that can be captured and turned into electricity. This is called hydroelectric power or
hydropower.
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Overview: Renewable energy |