Renewable Energy
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Does the UK need alternative energy supplies?
energy sources (UK 2003)
coal
41%
17%
2200
9%
2150
1%
2100
World estimated
reserves
2050
nuclear
HEP and other
renewables
oil
natural gas
32%
2000
1950
Natural
Gas
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Oil
Coal
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Renewable energy sources
These will not run out because they can be regenerated.
Examples are wind power, solar power, tidal power and
biomass.
Charcoal - a fuel produced
from wood (biomass)
Only 1% of the UK’s energy comes from these sources.
Can you think of a reason why?
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Solar energy
Photovoltaic cells are made
of the abundant element
silicon.
Photovoltaic cells have
low maintenance costs.
Photovoltaic cells are silent.
Solar panels
Why isn’t solar energy popular in the UK?
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Wind energy
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Wind energy - the disadvantages
In theory, the UK could generate all its electricity from
wind farms covering approximately 1% of the land.
But the problems are wind turbine design and cost.
Rotor blades can be damaged in strong and turbulent
winds.
It takes 30 wind farms to generate the same amount of
electricity as one coal-fired power station. The setting
up costs for wind farms are therefore more expensive
than for traditional, fossil fuel power stations.
Some people also consider the wind
farms as visually unattractive and noisy.
What are the advantages of wind energy?
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Advantages of wind energy
Wind farms create
jobs in rural areas.
Wind fuel is free.
Wind farms can be constructed in a
few months (thermal power stations
take between 6-10 years to complete).
cooling towers
Wind power can be
developed on a small scale.
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Hydroelectric power
Hydroelectric electricity is the most popular type of
renewable energy.
In some countries, such as Brazil, it represents most of
the energy produced. Hydroelectric energy is
produced from fast flowing water, such as at a waterfall
or by an artificial dam.
Dam at Donzere, France
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Hydroelectric power
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Hydroelectric power - impact of building dams
may decrease
flooding
downstream
dams control the
flow of water
tourists may be
attracted to the
area
silt is trapped behind
the dam and is not
transported
downstream where it
is needed for farmers
and fishermen
the water behind the dam is
stagnant and algae builds up
building dams floods large
areas
These are some of the advantages and disadvantages of building
a dam.
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Tidal energy
Energy is generated by the tidal rise and fall. The tides
come in and pass through holes in a dam wall. The water
is then trapped in a river estuary. Then the tide ebbs and
passes back through the barrage, driving the turbines and
producing electricity.
turbo generator
high tide
low tide
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incoming waves
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Geothermal energy
Geothermal energy is obtained from heated rocks and
molten magma under the Earth’s surface.
geothermal plant
Hot water
Cold Water
fractured rock
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Geothermal energy is generated extensively in
tectonic areas, such as Iceland and New Zealand.
Why is this the case?
Plate Map
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Match the statement with the energy source
Wave
located on the coast with a chamber
facing the prevailing wind
Solar
often located
in exposed
areasrays
such
mirrors
concentrate
the sun’s
onto
as mountainous
water-filled
blackregions
pipes
HEP
mirrors
concentrate
sun’s rays onto
water stored
in damsthe
is released
water-filled
black to
pipes
through turbines
generate electricity
Tidal
heat produced by rocks under the
powered by a man-made barrage,
Earth’s surface
usually found across an estuary
Wind
powered
by ain
man-made
barrage,
often located
exposed areas
such
usually
found across
an estuary
as mountainous
regions
Geothermal
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waterproduced
stored in by
dams
is released
heat
rocks
under the
throughsurface
turbines to generate electricity
Earth’s
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Biomass
is biological material from living, or recently living organisms, such as
wood, waste, (hydrogen) gas, and alcohol fuels.
Biomass is commonly plant matter grown to generate electricity or
produce heat.
Biomass energy is comes from five
distinct energy sources:
garbage
wood,
waste,
landfill gases
alcohol fuels.
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Biomass can be converted to other
usable forms of energy like methane
gas or transportation fuels like
ethanol and biodiesel
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