No need for coal-fired power stations

Courier Mail
01/12/2007 Page: 57

CLIMATE change has sparked a world wheat production crisis with extreme weather also responsible for increasing damage to cities and towns amounting to hundreds of billions of dollars each year. Such damage and loss of life will get worse as temperatures increase. A change to renewable energy could save much money if we can prevent the weather damage becoming worse.

Even now, solar power stations are likely to produce cheaper electricity over their lifetimes than coal. Although more expensive to build, solar power stations will have zero fuel cost, while the cost of coal is likely to rise. There is much research into "clean coal" technologies, trying to capture carbon dioxide emitted by power stations. This is estimated to double the price of electricity.

There is no need to build more coalfired power stations. Although taking this path in Australia will have only a small impact on the total world emissions of greenhouse gases, leadership by example is important to convince such countries as India and China to switch to clean energy. There will be some loss from future coal exports, but Australia could make money from development and export of solar technologies and equipment.

Australia is at the forefront of developing new technologies for low cost solar power. Professor David Mills heads the Solar Energy Group at Sydney University and is chairman of the company Solar Heat and Power formed to commercialise a new low cost solar system suitable for largescale power generation. The first commercial plant is being constructed at the Liddell power station in NSW to preheat water, with power generated by existing coal plant turbines.

According to Mills, this will be the world's lowest-cost solar electricity plant, producing power at 10 percent below advanced wind energy units. With solar thermal technology it is possible to store heat, as superheated water, to provide power around the clock and not just while the sun is out.

This is the problem with photovoltaic solar panels, which will be used for the solar power station to be built in northwest Victoria. The idea of turning sunlight directly into electricity sounds good, but with photovoltaic solar panels there is no cheap or practical way to store the power. The solar thermal systems being developed could be stand-alone or retrofitted to power stations to improve efficiency. This offers a way to reduce greenhouse gas emissions over the next 20 years, without abandoning existing power stations. It is likely this will be more economical than trying to capture and store carbon dioxide from them.

Another source of solar power is likely to come from roof-top solar panels. According to Professor Andrew Blakers from the Australian National University, the cost of producing electricity from solar panels will decline as a result of cutting the cost of silicon in the receptors by using thin slivers. Reduction in the cost of solar power will provide strong competition for wind energy, but is not likely to replace it. A mix of power sources is likely to be better than one. In southern Australia the short days and cloudy weather in winter make solar power less productive, while wind energy is more reliable than further north.

Nuclear energy is not a solution to reducing greenhouse gases. The extra energy cost in building a nuclear energy plant and processing the fuel still results in considerable greenhouse emissions. On a cost basis, nuclear energy is just not in the race. If electricity from nuclear energy is more than twice as expensive as a solar thermal power station, why are we even considering it?

Dr Peter Wylie is a researcher and consultant, specialising in environmental issues, including water, energy, climate change and sustainable farming. peter@horizonrural.com.au