Transcript Energy Resources energy_resource_gallery_walk

Energy Resource Gallery Walk
Essential Question:
What are the advantages and disadvantages to
the different ways we generate electricity?
1. OIL
How do we get electricity from it?
• Burn oil to heat water and make steam.
• Steam turns turbine, turbine turns generator
• Generator makes electricity.
1. OIL
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Advantages
Lot of electricity can be generated in one place, fairly cheap.
Transporting oil to power stations easy.
Power stations can be built almost anywhere.
Provides about 40% of our energy.
1. OIL
Disadvantages
• Main drawback is pollution. Produces carbon dioxide, which
contributes to climate change.
• Risk of oil spills.
• Impact on wildlife at drilling sites.
• Not renewable energy resource; once we've used it up, there isn't
any more.
What are fossil fuels? Give examples and explain why they
are called fossil fuels.
• Coal, oil, natural gas.
• Formed by bodies of dead animals and plants under ground, under
pressure for millions of years.
• Used in car engines, factories, and power plants to generate
electricity.
How is the burning of fossil fuels believed by scientists to be
causing global climate change?
• Burning fossil fuels adds carbon dioxide (CO2) to atmosphere.
• CO2 acts like a blanket, trapping heat in atmosphere, causing
climate to change.
What evidence is there that climate is changing dramatically?
1. Glaciers melting, rate of melting is speeding up.
2. Temperatures risen during the last 30 years; last 12 years
hottest on record.
3. Droughts longer and more extreme worldwide.
4. Stronger hurricanes and other tropical storms.
5. Ocean surface temperatures increasing.
6. Avg. sea level around the world rising.
What evidence is there for scientists to conclude that burning of fossil
fuels are contributing to climate change?
• Increases of CO2 in
atmosphere correspond
closely with increases in
CO2 emissions from
burning of fossil fuels.
• No evidence that
sunspots, earth’s orbit,
or volcanic activity are
causing it.
What are the likely effects of climate change on people and the
environment?
• Crop damage from heat, droughts, storms.
• Millions of people hurt by floods, droughts.
• Ticks and mosquitoes that carry tropical diseases like malaria can survive
longer and kill more people.
• Animals and plants that can’t adapt to warmer temps will die, e.g. polar
bears, coral reefs.
• More wildfires in forests.
• Increased acidity of oceans harms shellfish.
2. COAL
How do we get electricity from it?
• Same as oil.
2. COAL
Advantages
• Lot of electricity can be
generated in one place, fairly
cheap.
• Provides about 28% of our
energy. Big source of jobs in
some states.
2. COAL
Disadvantages
• Produces more carbon dioxide than oil or gas, contributes to
climate change.
• Also produces sulphur dioxide, contributes to acid rain.
2. COAL
Disadvantages
• Strip mining destroys
large areas of the
landscape.
• Power stations need
huge amounts of coal,
which means train-loads
of coal.
• Not renewable energy
source
3. NATURAL GAS
How do we get electricity from it?
• Same as oil.
3. NATURAL GAS
Advantages
• Gas easy to transport in pipes.
• Power stations very efficient,
produce little pollution compared
to oil and coal.
• Provides 20% of world’s energy.
3. NATURAL GAS
Disadvantages
• Still produces carbon dioxide, causing climate change.
• Not renewable energy source.
What is “Fracking?”
• Technique used to extract natural gas from oil shale beneath
the earths surface.
• Millions of gallons of water, sand & chemicals injected under
high pressure into well. Pressure fractures the shale and
opens cracks that enable natural gas to flow more freely out
of the well.
What is “Fracking?”
• Advantages: Cheap, easy way to get lots of natural gas.
• Disadvantages: Concerns over chemicals getting into
water supply.
http://www.youtube.com/watch?v=4ApZkNsXfJE
4. WIND
How do we get electricity from it?
• Wind blows the
propeller around,
which turns a
generator to
produce electricity.
4. WIND
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Advantages
Wind is free, needs no fuel.
Produces no waste or greenhouse gases.
Good for supplying energy to remote areas.
Renewable energy source, will never run out.
4. WIND
Disdvantages
• Wind not always predictable.
• Land for wind farms on coast more
expensive.
• Can look ugly.
• Can kill birds, flying insects.
• Can be noisy. Some new designs quieter.
5. HYDROELECTRIC
How do we get electricity from it?
• Water flows through tunnels river dam, turns turbines
that drive generators.
5. HYDROELECTRIC
Advantages
• Water is free, needs no fuel.
• Produces no waste or greenhouse gases.
• More reliable than wind, solar or wave power.
Electricity can be generated constantly.
• Renewable energy source, will never run out.
5. HYDROELECTRIC
Disadvantages
• Dams very expensive to build.
• Building dam floods land upstream, causing problems
for animals and plants.
• Not enough rivers.
6. GEOTHERMAL
How do we get electricity from it?
• Hot rocks underground heat water to produce steam.
• Steam comes up, used to drive turbines, which drive
electric generators.
6. GEOTHERMAL
Advantages
• No pollution, does not contribute to the greenhouse
effect.
• Power stations small, little impact on environment.
• No fuel is needed.
• Renewable energy source, will never run out.
6. GEOTHERMAL
Disadvantages
• Not many places have geothermal heat sources.
• Site may "run out of steam", may not be renewable
energy source.
• Hazardous gases and minerals may come up from
underground.
7. SOLAR
How do we get electricity from it?
• Sunlight hits a solar panel.
• Panel converts the light into electricity.
7. SOLAR
Advantages
• No pollution, does not contribute to the greenhouse
effect.
• Sunlight is free, no fuel costs.
• Can be used in remote places where hard to build power
plants.
• Handy for low-power uses like homes.
• Renewable energy source, will never run out.
Solar One power station (CA) uses the Sun's heat to make steam, and drive a generator
to make electricity.
As the Sun moves across the sky, the mirrors turn to keep the rays focused on the
tower, where oil is heated to 3,000°C. The heat from the oil is used to generate steam,
which then drives a turbine, which in turn drives a generator capable of providing
10kW of electrical power.
Dragon-Shaped Solar Stadium in Taiwan is 100% Powered by the Sun
California State University Northridge has installed 3,000 solar panels in a student parking
lot. The panels which also provide shade, produce 75 watts of power each reducing
energy costs for the university by more than $50,000.
7. SOLAR
Disadvantages
• Doesn't work at night.
• Very expensive to build solar power stations, though
cost coming down as technology improves.
• Can be unreliable unless you're in very sunny climate.
Germany is one of the cloudiest countries in Europe -- the sun only shines for about a third
of the year -- but within the last decade it has gone from near zero to producing 8,000 MW
of power from solar, the equivalent of eight nuclear power plants.
8. NUCLEAR
How do we get electricity from it?
• Same as fossil fuels, except "chain reaction" inside a nuclear
reactor makes the heat instead of burning coal/oil/gas.
• Heat generated by splitting of uranium atoms.
• Water pumped through reactor to make steam.
• Steam drives turbines which drive generators.
8. NUCLEAR
Advantages
• Costs about the same as coal, not expensive.
• Does not produce carbon dioxide, does not contribute to
climate change.
• Produces huge amounts of energy from small amounts of
fuel.
• Produces small amounts of waste.
8. NUCLEAR
Disadvantages
• Waste produced is very, very dangerous. Must be sealed
up and buried for many thousands of years.
• For all that time, must be kept safe from earthquakes,
flooding, terrorists.
• Nuclear accident can be major disaster.
• Not renewable; once it’s gone it’s gone.
The Hanford site represents two-thirds of the nation's high-level radioactive waste by
volume. Today, Hanford is the most contaminated nuclear site in the United States and
is the focus of the nation's largest environmental cleanup.
http://usatoday30.usatoday.com/news/nation/environment/story/2012-01-25/hanfordnuclear-plutonium-cleanup/52622796/1
9. WAVES
How do we get electricity from it?
• Waves cause water in chamber to rise and fall, which means
that air is forced in and out of the hole in the top of the
chamber.
• Turbine over hole turned by air rushing in and out.
• Turbine turns generator, which makes electricity.
9. WAVES
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Advantages
Waves are free, no fuel needed.
No waste produced, no climate change.
Not expensive to operate and maintain.
Can produce a great deal of energy.
Renewable resource.
9. WAVES
Disadvantages
• Waves not predictable, may get a lot or a little.
• Some designs noisy. But so are waves, so noise
unlikely to be problem.
• Must be able to withstand very rough weather.
Where Our Electricity Comes From
• http://www.usatoday.com/story/money/busin
ess/2012/11/05/germany-renewablepower/1682675/