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 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 (CO 2 ) to atmosphere.
CO 2 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 CO 2 in atmosphere correspond closely with increases in CO 2 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 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 energy source . renewable • 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
to make electricity. (CA) uses the Sun's heat to make steam, and drive a generator 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/hanford nuclear-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 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
•