The following information has been gathered from:
U.S. Dept. of Energy Efficiency and Renewable Energy AND
National Renewable Energy Laboratory
have been harnessing the wind's energy for hundreds of years.
From old Holland to farms in the United States, windmills
have been used for pumping water or grinding grain. The windmill's
modern equivalent -a wind turbine- can use the wind's energy
to generate electricity.
Wind turbines, like windmills, are mounted on a tower to
capture the most energy. Turbines catch the wind's energy
with their propeller-like blades. Usually, two or three blades
are mounted on a shaft to form a rotor. Wind, for the most
part, is a reliable source of renewable energy that produces
zero emissions thereby increasing our local air quality.
energy works anytime that the sun is shining, but more electricity
is produced the stronger the sun shines.
There are a variety of technologies that have been developed
to take advantage of solar energy (energy produced by the
sun). These include:
- Photovoltaic (solar cell) systems: Producing electricity
directly from sunlight.
- Concentrating solar systems: Using the sun's heat
to produce electricity.
- Passive solar heating and daylighting: Using solar
energy to heat and light buildings.
- Solar hot water: Heating water with solar energy.
- Solar process heat and space heating and cooling:
Industrial and commercial uses of the sun's heat.
cover more than 70% of Earth's surface, making them the world's
largest solar collectors. The sun's heat warms the surface
water a lot more than the deep ocean water, and this temperature
difference creates thermal energy. Just a small portion of
the heat trapped in the ocean could power the world.
The ocean can produce two types of energy: thermal energy
from the sun's heat, and mechanical energy from the tides
and waves. Even though the sun affects all ocean activity,
the gravitational pull of the moon primarily drives the tides.
And the wind powers the ocean waves. Because ocean energy
is abundant and non-polluting, today's researchers are exploring
ways to make ocean energy economically competitive with fossil
fuels and nuclear energy.
word "geothermal" literally means "Earth" plus "heat." The
geothermal resource is the world's largest energy resource
and has been used by people for centuries. In addition, it
is environmentally friendly. It is a renewable resource and
can be used in ways that respect rather than upset our planet's
delicate environmental balance.
The Earth's crust is a bountiful source of energyčand fossil
fuels are only part of the story. Heat or thermal energy is
by far the more abundant resource. To put it in perspective,
the thermal energy in the uppermost six miles of the Earth's
crust amounts to 50,000 times the energy of all oil and gas
resources in the world! The following are technologies that
have been invented to use geothermal energy to produce electricity:
- Geothermal electricity production: Generating electricity
from the earth's heat.
- Geothermal direct use: Producing heat directly
from hot water within the earth.
- Geothermal heat pumps: Using the shallow ground
to heat and cool buildings.