bg7 Clean Energy Technologies
bg7 Clean Energy Technologies
bg7 Clean Energy Technologies
W
ind, solar, biomass, and water are not
the only sources of clean, environmentally
friendly energy. Other energy sources can
also provide heat, light, and electricity without pol-
luting the air or disturbing large areas of land or
water. This backgrounder covers a few of these new
technologies, some of which are likely to become
mainstream sources of energy in the approaching
decades.
Geothermal heat comes from pressure and nuclear reac-
Geothermal Heat tions at the Earth’s core.
People have known Photo courtesy of the Geothermal Education Office
since ancient times
that the Earth’s inte- volcanically heated rocks. In Iceland for instance,
rior is very hot. The wells are drilled into volcanic rocks to extract hot
temperature of the water and steam. The hot water or steam is carried
Earth’s core is esti- to communities in insulated pipes and used to heat
mated to be between homes and businesses. In some cases, the water is
3000 and 5000o C (sci- superheated (heated under pressure to temperatures
entists are still not greater than 100o C). Superheated water quickly turns
sure what the exact to high-pressure steam, which can turn high-speed
temperature is). This turbines that drive electrical generators.
heat is generated by
the slow breakdown of Ground Source Heat Pumps
radioactive elements, The temperature of the soil below about 2 metres
Heat from the Earth’s interior
and by the immense remains constant regardless of the weather or season.
is known as geothermal heat.
gravitational pressures Photo courtesy of United States In most places throughout southern Canada, soil tem-
acting on the rocks and Geological Survey peratures at this depth hover between 5 and 10o C.
minerals of the Earth’s
interior. Temperatures in excess of 500o C can be
found in the Earth’s crust just a few thousand metres
below the surface, but geothermal heat right at the
surface of the land is barely detectable.
A Renewable Energy Project Kit Another internet tool by: The Pembina Institute
Backgrounder
Other Clean Energy Technologies Teach...build...learn...renewable energy! Page 2 of 3
A Renewable Energy Project Kit Another internet tool by: The Pembina Institute
Backgrounder
Other Clean Energy Technologies Teach...build...learn...renewable energy! Page 3 of 3
across this membrane produces an electric charge,
similar to that produced by a regular alkaline battery.
But unlike the battery, which goes dead after the
chemicals inside it are used up, the fuel cell contin-
ues to produce electricity as long as it receives fresh
supplies of air and hydrogen. The only by-product
of the process is water, which the fuel cell releases
as steam.
A Renewable Energy Project Kit Another internet tool by: The Pembina Institute