Geothermal Energy Video Lecture - Class 10

you may have relaxed in a natural Hot
Springs pool or seen the Old Faithful
geyser blasting hot water into the air
in Yellowstone National Park but have
you ever thought of where all that heat
comes from well it comes from deep
beneath the surface of the earth and
it's called geothermal energy and we can
use it to generate clean renewable
electricity okay here's how geothermal
works heat from the Earth's crust warms
water that is seeped into underground
reservoirs in some places when water
becomes hot enough it can break through
the Earth's surface as steam or hot
water this usually happens where the
Earth's crust or plates meet and shift
in the past taking advantage of
geothermal energy was limited to areas
where hot water flowed near the surface
but as geothermal technologies advanced
we can leverage even more of these
natural renewable energy sources
engineers have developed a few different
ways to produce power from geothermal
wells drilled into the ground have a
look at this it's a dry steam geothermal
power plant and it's the most common
type of geothermal technology used today
underground steam flows directly to a
turbine to drive a generator that
produces electricity pretty
straightforward another geothermal
technology is called a flash steam power
plant a pump pushes hot fluid into a
tank at the surface where it cools as it
cools the fluid flashes or quickly turns
into vapor the vapor then drives a
turbine and powers a generator
a binary cycle plant works differently
it uses two types of fluid hot fluid
from underground heats a second fluid
called a heat transfer fluid in a giant
heat exchanger the second fluid has a
much lower boiling point than the first
fluid and so it flashes into vapor and a
lower temperature when the second fluid
flashes it spins a turbine that drives a
generator the environmental benefits of
this clean round-the-clock renewable
energy source are substantial low
emissions small physical footprint and
minimal environmental impact the few
byproducts that can come up are often
rejected underground geothermal energy
can also help recycle waste water in
California waste water from the city of
Santa Rosa is injected into the ground
to generate more geothermal energy some
plants do produce solid waste but that
solid waste may contain minerals that we
can remove and sell which lowers the
cost of this energy source the US
Geological Survey estimates that
untapped geothermal resources in the
United States if developed could supply
the equivalent of 10 percent of today's
energy needs and cut our dependence on
fossil fuels in fact electricity
generated by geothermal energy already
provides about 60% of the power along
the Northern California coast from the
Golden Gate Bridge to the Oregon State
Line geothermal energy helping to push
America toward energy independence and a
clean renewable way to meet our growing
energy demands