 |
|
|
 Some experts suggest renewable sources like wind power will supply 20% of Australia's energy needs by 2020 |
|
|
|
|
|
|
|
 |
Australia looks to a powerful future |
|
 |
|
|
|
|
The climate change debate is hotting up again.
News of severe hurricanes, record temperatures and melting polar ice has strengthened interest in global warming and how to reduce emissions of greenhouse gases.
Australia is a small contributor to global greenhouse gas emissions, but its main source of electricity, coal, produces large quantities of carbon dioxide (C02), one of the main greenhouse gases. Thanks largely to coal, Australians enjoy relatively cheap electricity, paying three times less than some countries. However, coal's critics say the price of our electricity does not take into account the real environmental cost of greenhouse gas emissions.
Three-quarters of Australia's electricity comes from coal, 14 per cent from natural gas, eight per cent from renewable sources (mainly hydroelectric, wind power and bioenergy) and one per cent from oil. Worldwide, coal accounts for just 40 per cent of electricity generation. Although nuclear power provides 17 per cent of global electricity, Australia has no nuclear power stations.
Coal is still the easiest and cheapest way to supply the continuous, reliable, base-load electricity that powers Australian industries, factories and homes. On current usage, Australia has enough coal for at least 200 years. Whether we like it or not, coal will have to play a major role in the transition to a more sustainable future.
But the experts agree that coal-fired electricity generation needs to clean up its act. Australia has the capacity to make coal power cleaner by storing CO2 deep underground in stable rock formations. This geosequestration process is particularly attractive because of Australia's large geological storage capacity and relatively stable land mass.
|
|
Nuclear power supplies 17% of global electricity
|
According to Frank van Schagen from the Cooperative Research Centre (CRC) for Coal in Sustainable Development, options for improved coal-fired power generation include coal gasification, oxygen-fired combustion and post-combustion capture.
Frank said these technologies "will provide opportunities to capture and store carbon dioxide and help reduce the greenhouse impact of coal-burning. It may also be possible for coal-fired power stations to use wind and solar power to supplement or even replace some of the coal they burn."
Natural gas is also a fossil fuel, but it produces much less CO2 per unit of electricity than coal. Gas-fired power is easier to turn on and off than coal, making it a valuable source of additional energy during peak periods. However, gas has increased in price substantially in recent years, and the economics of future gas-fired generation are uncertain.
Richard Wise from the Business Council for Sustainable Energy said natural gas is projected to supply 18 per cent of Australia's energy needs by 2020. The key will be to ensure maximum efficiency by using the heat that is generated as well as the electricity, a concept known as co-generation.
'Sustainable energy' options, which include some renewable technologies, are gaining strength but are still more expensive than coal and natural gas. These include wind, photovoltaic (solar), geothermal (using hot underground rocks to produce steam that can drive power station turbines) and hydroelectric power. Bioenergy sources include landfill gas and bagasse (sugarcane waste) co-generation. Richard predicts that sustainable energy options will account for one-fifth of our power generation needs by 2020.
"Wind, hydroelectric, bioenergy and geothermal power are the most promising longer-term sustainable energy sources for Australia," he said.
Nuclear power has not so far been regarded as a serious option for Australia. The world's worst nuclear accident, at Chernobyl in 1986, was a severe setback for the image of nuclear power, but 20 years on, the threat of global warming has renewed interest in nuclear power as a proven and clean source of electricity.
The Prime Minister, John Howard, and the Federal Treasurer, Peter Costello, have both recently expressed support for consideration of nuclear power in Australia.
"Nuclear power has the lowest greenhouse gas emissions of any power generation method," said John Bartlett from ANSTO (the Australian Nuclear Science and Technology Organisation). "Its potential use should form part of a rational debate on Australia's energy options."
According to John, nuclear fission could make a significant contribution to our base-power requirements within 20 to 50 years, particularly as the so-called 'Generation IV' nuclear power plants are developed.
"The Generation IV plants will extract maximum energy from available fuel and minimise waste volumes and lifetimes," John said. "They also offer the exciting possibility of being able to split water molecules to produce hydrogen gas for use in internal combustion engines, and to desalinate water for drinking."
The main criticisms of nuclear power relate to safety concerns such as the potential for terrorist attacks and the generation of long-lived radioactive wastes. John explained these can be addressed by employing advanced safety features and using extremely durable materials, such as Synroc, to immobilise long-lived radioactive waste.
Under the Kyoto Protocol, the Australian Government has agreed to reduce its greenhouse gas emissions between 2008 and 2012 to a level eight per cent higher than 1990 emissions. According to the Australian Greenhouse Office, Australia is on track to meet this target.
The CRC for Coal in Sustainable Development has estimated that if Australia were to reduce its emissions to the 1990 level by 2050, coal would account for just 64 per cent of national electricity generation, natural gas six per cent and hydroelectricity four per cent. Other renewables would need to rise to 26 per cent.
The Australian Government has established a $500 million fund to support the commercial demonstration of new technologies for low carbon dioxide emissions. Every dollar must be matched by two dollars from the private sector.
Australia has major technological challenges to overcome before it finds the key to sustainable long-term electricity generation. Coal can provide a bridge to the future, but its years may be numbered.
|
|
|
|
|
© Copyright 2006 - Australian Nuclear Science and Technology Organisation (ANSTO)
| Privacy policy | Unsubscribe | Subscribe | Enquiries | |
|
|
