of electricity The discovery What is the Greenhouse Effect?

Transcription

1 The discovery of electricity What is the Greenhouse Effect? The earth s atmosphere has several gases which together act like a blanket to keep the earth at a comfortable temperature. If these gases were not there, the earth would be much colder, probably by about 30 degrees Celsius. Greenhouse gases causing the most problems for our environment are carbon dioxide, methane, chlorofluoro-carbons, halons, tropospheric ozone and nitrous oxide. Because of a fast-growing world population and its need for more energy-consuming appliances, more cleared land and transport, these gases are increasing in the atmosphere. 1 Scientists around the world are concerned that this increase could warm the earth and change our climate. In Victoria, the changes could mean a warming of temperatures by two to four degrees Celsius by the year 2030, causing a rise of up to 30 centimetres in sea levels, heavier rainfall, more fl ash fl ooding, increased wind speed and more bushfi res. These changes could happen gradually unless we fi nd ways of slowing down the greenhouse effect by controlling the amount of gases released to the atmosphere. The discovery of electricity fact sheets reviewed and updated with the assistance of STAV Publishing

2 What causes the greenhouse effect? Put simply, humans cause it. How? By burning fossil fuels such as brown coal, black coal, gas and oil in power stations, industry and transport. The burning of fossil fuels releases carbon dioxide and causes about half of the greenhouse effect. By cutting down too many trees. More trees are needed because they absorb carbon dioxide. By using aerosol sprays and refrigeration systems which release chlorofl uorocarbons and halons. These two gases also damage the upper ozone layer, causing the <ozone hole> that appears each spring over Antarctica. By the growing of rice, farming of animals, and leakages from natural gas pipes, all of which release methane. Annual contribution of major greenhouse gases 2 Methane CH 4 20% Nitrous Oxide N 2 O Other Carbon Dioxide CO 2 6% 4% 70%

3 What is being done about it? <How much coal does it take to run a light-globe? Activity> 3 Reducing carbon dioxide discharges isn t easy, but here are a few possible solutions. Solution 1: Conserving energy Energy conservation is the best way to cut down our carbon dioxide releases. In the home, it often requires little effort. Just a few examples: Use cold water to wash your clothes. Using a cold setting will save 3 kilograms of greenhouse gas per wash (compared to a hot wash). When you ve fi nished watching a video or TV or listening to a CD, switch the unit off completely (preferably at the wall). You ll save anywhere between 20 and 85 kg of greenhouse gas by doing this. Likewise, when you ve fi nished with your computer for the day turn it completely off. Shorter showers and fi xing dripping hot taps are also great ways to save energy and water. Buying more energy effi cient appliances and <light globes>

4 Solution 2: Electricity from waste Rubbish tips Decaying food scraps discharge a lot of methane, which, molecule for molecule, is many times more damaging to the atmosphere than carbon dioxide. Methane is used as a fuel for small power stations built on top of rubbish tips. Embracing methane power technology means less brown coal is burned and local councils not be discharging methane. Embracing methane power technology would mean less brown coal would be burned and local councils would not be discharging methane. 4 Co-generation Co-generation is when heat and power are produced and used at the same time from the same energy source. The heat, which in the past usually went to waste, is either a by-product of a manufacturing process or a by-product of the burning of a fuel like gas to produce electricity. An example of the latter is a car manufacturer with a gasfi red turbine producing electricity for its manufacturing equipment and, at the same time, using the heat from the gas turbine exhaust to dry painted cars. With the combined use of heat and power, industries can cut their total energy use by more than 50 per cent.

5 Solution 3: Other less harmful fuels <Wind>, <water> and <solar> More electricity will gradually come from fuels that are renewable, especially wind, water and the sun. At the moment, the equipment to use these fuels costs much more than equipment for brown coal power stations. All of us have to decide if we are prepared to pay these costs. Of the renewable fuels, wind shows the most promise for Victoria. Activity Research some of the arguments for and against wind turbines. Gas Gas-fi red power stations release half as much carbon dioxide as brown coal stations of the same generating size. We have to remember, though, that our use of gas is limited as it is not available in the same large quantities as brown coal. 5

6 6 CitiPower and Powercor sponsor Landcare days. <What s the real story? Activity > Solution 4: <Planting trees> Trees (especially the fast-growing types) absorb and store carbon dioxide from the atmosphere. Victoria s supply industry plants thousands of trees on its many hectares of land throughout Victoria. It is also helping with community tree planting programs. About 350 healthy, fast growing trees are needed to balance the carbon dioxide released in the production of electricity for just one Victorian household. More information Reducing emissions and planting trees < eet.com.au/> Greenhouse < < < qa_greenhouse.htm> < < cutting_pollution.pdf> Ozone hole < glossary/ozone.shtml>

7 How much coal does it take to run a light-globe? Activity Approximately 1.39 kg of greenhouse gas emissions (including carbon dioxide, nitrous oxide and sulphur dioxide) is produced for every kilowatt hour (kwh) of electricity produced from coal. The first challenge! Calculate how much brown coal (lignite) is required to power one standard 100 W light globe in your house for one year, and then calculate how much greenhouse gas this amount of coal produces! Assume the light-globe will be on 24 hours a day for one year. Information you will need to solve the problem: 1 kwh = 1 kilowatt of power for one hour 1 kg of lignite produces 11.3 MJ of energy. 1 megajoule (MJ) = kilowatt hour The effi ciency of the best coal-power stations is approximately 40% If you get stuck, have a look at the following websites. Origin Energy: A greenhouse calculator can be found at the environment section on this site: How Stuff Works: This site is American, so you will need to convert all the units into metric measurements: science-channel.htm Next step Now you know how much coal is needed to power just one light globe in your house, have a look at some of the other appliances you use everyday and calculate how much coal they require. Here are some suggestions: 7 Appliance Toaster Clock radio Computer screen Power usage (W) 820 W 13 W 40 W If you changed all your light globes to energy saver, low wattage globes, how much less green house gas would your house produce?

8 What s the real story? Activity Around the world, energy companies, governments, scientific institutions and individuals are looking at the consequences of an enhanced greenhouse effect. Working in groups, choose one of the topics below and find out as much as you can about it. Hold a class conference, where every group presents their findings as a poster, scientific style paper or multimedia presentation. 8 Suggestions Topics 1. The majority of Australia s electricity comes from coal, despite it being the cause of so much greenhouse pollution. Choose one of the topics below: a. Find out how coal is formed, and what types of coal are used by Australian industries. b. Research the alternatives to coal power in Australia, and decide whether these alternatives are suitable in all circumstances. c. Find out about three current, Australian scientifi c studies being undertaken into coal and what they have found out so far. 2. Australia has received extensive criticism from the world community by refusing to sign the Kyoto Protocol. a. What is the Kyoto Protocol and who has and who hasn t signed it? b. What might the Protocol mean for Australia? c. What reasons has Australia given for not signing the Protocol? d. Do you think the Protocol will work to reduce the effect of greenhouse gases on the environment? Why or why not? 3. What can the average Australian do to reduce the amount of greenhouse gases they produce? Will these measures make a real difference why or why not? What are some of the problems involved with trying to make a difference at the local level? Your group might like to design a survey to fi nd out people s attitudes towards the Greenhouse Effect. Your group could contact some of the organizations working on solutions for the enhanced greenhouse effect, and ask for information to be sent to you. You could include this information in your presentation. You could write to your local member of parliament, asking about the Government position on the Greenhouse Effect and the Kyoto Protocol.

9 What is the Greenhouse Effect? The earth s atmosphere has several gases which together act like a blanket to keep the earth at a comfortable temperature. If these gases were not there, the earth would be much colder, probably by about 30 degrees Celsius. Greenhouse gases causing the most problems for our environment are carbon dioxide, methane, chlorofluoro-carbons, halons, tropospheric ozone and nitrous oxide. Because of a fast-growing world population and its need for more energy-consuming appliances, more cleared land and transport, these gases are increasing in the atmosphere. Scientists around the world are concerned that this increase could warm the earth and change our climate. In Victoria, the changes could mean a warming of temperatures by two to four degrees Celsius by the year 2030, causing a rise of up to 30 centimetres in sea levels, heavier rainfall, more fl ash fl ooding, increased wind speed and more bushfi res. These changes could happen gradually unless we fi nd ways of slowing down the greenhouse effect by controlling the amount of gases released to the atmosphere. What causes the greenhouse effect? Put simply, humans cause it. How? By burning fossil fuels such as brown coal, black coal, gas and oil in power stations, industry and transport. The burning of fossil fuels releases carbon dioxide and causes about half of the greenhouse effect. By cutting down too many trees. More trees are needed because they absorb carbon dioxide. By using aerosol sprays and refrigeration systems which release chlorofl uorocarbons and halons. These two gases also damage the upper ozone layer, causing the <ozone hole> that appears each spring over Antarctica. By the growing of rice, farming of animals, and leakages from natural gas pipes, all of which release methane. What is being done about it? Reducing carbon dioxide discharges isn t easy, but here are a few possible solutions. Solution 1: Conserving energy Energy conservation is the best way to cut down our carbon dioxide releases. In the home, it often requires little effort. Just a few examples: Use cold water to wash your clothes. Using a cold setting will save 3 kilograms of greenhouse gas per wash (compared to a hot wash). When you ve fi nished watching a video or TV or listening to a CD, switch the unit off completely (preferably at the wall). You ll save anywhere between 20 and 85 kg of greenhouse gas by doing this. Likewise, when you ve fi nished with your computer for the day turn it completely off. Shorter showers and fi xing dripping hot taps are also great ways to save energy and water. Buying more energy effi cient appliances and <light globes> Solution 2: Electricity from waste Rubbish tips Decaying food scraps discharge a lot of methane, which, molecule for molecule, is many times more damaging to the atmosphere than carbon dioxide. Methane is used as a fuel for small power stations built on top of rubbish tips. Embracing methane power technology means less brown coal is burned and local councils not be discharging methane. Embracing methane power technology would mean less brown coal would be burned and local councils would not be discharging methane. Co-generation Co-generation is when heat and power are produced and used at the same time from the same energy source. The heat, which in the past usually went to waste, is either a by-product of a manufacturing process or a by-product of the burning of a fuel like gas to produce electricity. An example of the latter is a car manufacturer with a gas-fi red turbine producing electricity for its manufacturing equipment and, at the same time, using the heat from the gas turbine exhaust to dry painted cars. With the combined use of heat and power, industries can cut their total energy use by more than 50 per cent. Solution 3: Other less harmful fuels <Wind>, <water> and <solar> More electricity will gradually come from fuels that are renewable, especially wind, water and the sun. At the moment, the equipment to use these fuels costs much more than equipment for brown coal power stations. All of us have to decide if we are prepared to pay these costs. Of the renewable fuels, wind shows the most promise for Victoria. The discovery of electricity fact sheets reviewed and updated with the assistance of STAV Publishing

10 Activity Research some of the arguments for and against wind turbines. Gas Gas-fi red power stations release half as much carbon dioxide as brown coal stations of the same generating size. We have to remember, though, that our use of gas is limited as it is not available in the same large quantities as brown coal. Solution 4: <Planting trees> Trees (especially the fast-growing types) absorb and store carbon dioxide from the atmosphere. Victoria s supply industry plants thousands of trees on its many hectares of land throughout Victoria. It is also helping with community tree planting programs. More information Reducing emissions and planting trees < eet.com.au/> Greenhouse < gh_faq.htm> < faq/page5.html> < planetslayer/greenhouse_qa_greenhouse. htm> < classrooms/1_1.html> < climate_cutting_pollution.pdf> Ozone hole < glossary/ozone.shtml> About 350 healthy, fast growing trees are needed to balance the carbon dioxide released in the production of electricity for just one Victorian household.