Transcript WIND POWER (2).

Alysse Riggs and Julie Davis
General Information
 In reality, wind energy is a form of solar energy
 The sun's radiation heats different parts of the
earth at different rates when different areas absorb
or reflect at different rates.
 Hot air rises, reducing the atmospheric pressure at
the earth's surface, and cooler air is drawn in to
replace it.
 Air has mass, and when it is in motion, it contains
the energy of that motion("kinetic energy")
The Main Goal
 To create alternative energy
that was renewable
 That did not create
pollution in the air and
water
 That could replace
nonrenewable sources and
pollution in the near future
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Making A Difference
 It is a clean source of renewable
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energy that does not create air or
water pollution
 The biggest wind turbines can
power over 600 houses
 Global capacity was
approximately 70,000 megawatts
(1 megawatt can power over 250
homes)
 By 2050 the answer to one third
of the world's electricity needs
will be found blowing in the
wind.
The Wind Turbines
 Two Groups of wind turbines:
horizontal-axis turbine and
vertical-axis turbine (egg-beater)
 Turbines are made of steel. The
blades are made of fiberglassreinforced polyester or woodepoxy.
 The output of a wind turbine
depends on the turbine's size and
the wind's speed through the
rotor.
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Wind Turbines Cont.
 A wind energy system transforms
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the kinetic energy of the wind into
mechanical or electrical energy
 Electricity production and
consumption are most commonly
measured in kilowatt-hours (kWh).
 A kilowatt-hour means one kilowatt
(1,000 watts) of electricity produced
or consumed for one hour.
 Ex: One 50-watt light bulb left on for
20 hours consumes one kilowatthour of electricity (50 watts x 20
hours = 1,000 watt-hours = 1
kilowatt-hour).
Technological Obstacles
 Wind turbines - Below 8-10 mph wind speed they do not
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generate and have to cut out for safety reasons above 56 mph.
Their maximum generation is reached at about 30 mph.
Wind Farms - generate some power for 70-75% of the time but
this is often a mere trickle, so the total electricity produced is
only about 26% of their full potential.
The electricity produced cannot be stored and feeding it into the
national grid is complex and costly – a bill ultimately paid by the
consumer.
Coal or gas-fired power stations are essential to maintain
uninterrupted supplies of electricity when the wind is not
blowing
Developers claim a turbine lifespan is 20-25 years but many are
being replaced after just 9-12 years – with yet larger turbines
Political / Economic Obstacles
 The electricity produced cannot be stored and feeding
it into the national grid is complex and costly , which
is ultimately paid by the consumer.
 Wind turbines are being replaced every 9-12 years
which is costing more money
Negative Environmental Impacts
 A turbine 375 feet high requires a
base of some 1000 tons of reinforced
concrete, to say nothing of the
materials needed to build service
roads. Together with peat
destruction on peat-rich sites, this
means that wind farms can take
years to pay back the carbon dioxide
they release during and after
construction, reducing even further
their contribution to climate
change.
 Birds unaware of wind turbines
often crash into them and are killed
as a result.
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