Energy Sources
What is the difference between renewable
and nonrenewable energy resource?
• A nonrenewable resource is a natural
resource that cannot be re-made or regrown at a scale comparable to the rate
at which it is used.
• Renewable resources are natural
resources that can be replenished in a
short period of time.
Fossil Fuels:
Nonrenewable
Coal, Oil and Natural Gas are
called "fossil fuels” because they have been
formed from the fossilized remains of
prehistoric plants and animals.
They provide around 66% of the world's
electrical power, and 95% of the world's total
energy demands
Advantages of Using Fossil Fuels
• Very large amounts of electricity can be
generated cheaply
• Transporting it is easy
• Very efficient
• Power stations that use fossil fuels can be
built anywhere
Disadvantages of Using Fossil Fuels
• Produces carbon dioxide when burned, which
contributes to global warming
• Burning coal produces sulfur dioxide, causes acid rain
• Oil spills
• Mining coal is difficult, dangerous, and harms the land
Nuclear Power:
Nonrenewable
• Nuclear power is
generated using Uranium, which is a metal
mined in various parts of the world.
• Nuclear power produces around 11% of the
world's energy needs, and produces huge
amounts of energy from small amounts of
fuel, without the pollution that you'd get from
burning fossil fuels.
Advantages to Using Nuclear Power
• Fairly cheap
• Does not produce carbon dioxide or sulfur
dioxide, so it doesn’t contribute to global
warming or acid rain
• Produces huge amounts of energy from small
amounts of fuel
• Produces small amounts
of waste
Disadvantages of Nuclear Power
• Although not much waste is produced, the
waste is very, very dangerous.
Solar Power:
Renewable
–
–
Solar Cells really
called “photovoltaic" or
"photoelectric" cells) convert light directly
into electricity.
• In a sunny climate, you can get enough
power to run a 100W light bulb from just
one square meter of solar panel.
Advantages to Solar Power
• Free
• Does not produce pollution
• Can be used in remote locations
Disadvantages
to Solar Power
• Doesn't work at night
• Very expensive to build solar power
stations
• Power stations take up lots of space/land
• Unreliable unless you're in a very sunny
climate
Wind Power:
Renewable
• The Babylonians and Chinese
were using wind power to pump
water for irrigating crops 4,000 years ago, and
sailing boats were around long before that.
• Wind power was used in the Middle Ages, in
Europe, to grind corn, which is where the term
"windmill" comes from.
Advantages to Wind power
•
•
•
•
Wind is free
Needs no fuel to be produced
Produces no waste or pollution
The land beneath windmills can usually
still be used for farming
• Can be used in remote areas
Disadvantages of Wind Power
• Unreliable
• Can be expensive depending upon
land cost
• Can kill birds
• Affects television reception nearby
• Noisy
Hydroelectricity
: Renewable
• A dam is built to trap water, usually in a
valley where there is an existing lake.
• Water is allowed to flow through tunnels in
the dam, to turn turbines and thus drive
generators.
• Hydro-electricity provides 20% of the
world’s power
• This is how we get our electricity.
Advantages of
Hydroelectricity
•
•
•
•
•
•
Free except for cost of dam
No waste or pollution
Much more reliable than wind, solar or wave power
Water is stored behind dam for use
Electricity can be generated constantly, unlike other
renewable resources
Disadvantages to
Hydro-electricity
•
• Dams are very expensive to build
• Building dams floods areas upstream, affects
wildlife
• Finding a suitable site can be difficult
• Water quality and quantity downstream can
be affected, affects wildlife
Biomass- Renewable
• Biomass includes plant and animal
wastes, trees, other living material.
• Plant and animal waste is used to
produce fuels such as methanol,
natural gas, and oil. We can use
rubbish, animal manure, woodchips,
seaweed, corn stalks and other wastes.
Sugar cane is harvested and taken to a mill, where it is crushed
to extract the juice. The juice is used to make sugar, whilst the
left-over pulp, called "bagasse" can be burned in a power
station.
Other solid wastes, can be burned to provide heat, or used to
make steam for a power station.
Advantages to
Biomass
• Recycles waste that would just be
thrown away
• Cheap
• Less demand on the Earth's resources
Disadvantages to Using Biomass
• Collecting the waste can be difficult
• Must be burned, so generates pollution
(carbon dioxide-global warming- and
sulfur dioxide-acid rain)
• Using trees cuts down on forests and
contributes to global warming
Geothermal Power:
Renewable
–
Hot rocks underground heat
water to produce steam.
We drill holes down to the hot region, steam
comes up, is purified and used to drive
turbines, which drive electric generators.
Advantages to
Geothermal Power
• No pollution, does not contribute to global warming or
acid rain
• Not much impact on environment
• No fuel is needed
• Very cheap, once holes are drilled
Disadvantages to
Geothermal Power
• Not many suitable sites because hot rocks are needed
and type of rock must be easily drilled through.
• Site may "run out of steam”
• Hazardous gases and minerals may come from
underground, and can be difficult to safely dispose of
Tidal Power:
Renewable
• Works like hydro-electric but dam is much bigger.
• A huge dam (called a "barrage") is built across a river
estuary. When the tide goes in and out, the water
flows through tunnels in the dam.
• The ebb and flow of the tides can be used to turn a
turbine, or it can be used to push air through a pipe,
which then turns a turbine. Large lock gates, like the
ones used on canals, allow ships to pass.
• Only around 20 sites in the world have been identified
as possible tidal power stations.
Advantages to Tidal Power
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•
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Free once barrage is built
It produces no pollution
It needs no fuel
Reliable and predictable (because tides
are predictable)
Disadvantages to
Tidal Power
• Barrage is very expensive to build
• Barrage affects the environment for many miles
upstream and downstream
• Few suitable sites for tidal barrages
• Only provides power for around 10 hours each day,
when the tide is actually moving in or out.
sources
• http://www.darvill.clara.net/altenerg/fossil.h
tm
• http://www.umich.edu/~gs265/society/fossil
fuels.htm