CSIRO scientist Dr Lincoln Paterson, who is researching carbon dioxide storage, says all the elements of the technology exist, but have yet to be tied into a power station. A demonstration project at Loy Yang B is capturing carbon from flue gases. And in a demonstration near Port Campbell last year, 60,000 tonnes of carbon dioxide was removed from one underground ''reservoir'' and piped into another two kilometres away. ''If cost was not a factor you could do it today … but the reality is you can't ignore cost. Cost is a critical element of the practicality,'' Paterson says. Against this backdrop, Australia, a uranium exporter, has about 39 per cent of the world's most easily accessible uranium (but political restrictions mean it supplies 19 per cent of the world's demand). The Federal Government even admits that nuclear power helps reduce greenhouse emissions - but refuses to consider using it. ''Nuclear power globally is part of the climate change solution,'' says federal Resources and Energy Minister Martin Ferguson. ''The Government accepts that and we are committed to the development of the uranium mining industry with all the associated safeguards. Australia, unlike a lot of those other nations, is energy rich, hence our focus on the immediate energy options. Here there is no requirement on us as a nation to go down the nuclear path. ''It is the view of the Australian community that we should pursue all energy options other than nuclear.''

While no proposal to explore nuclear energy has been prepared or is under consideration for cabinet, senior Government figures are speculating about what Australia's options might be if renewable energy technologies and carbon capture don't deliver sufficient cuts in emissions and adequate energy supply. The Government expects Australia's population to almost double to 35 million by 2049. Even with efficiencies, that is going to mean a big increase in electricity demand. Professor John Price, of Monash University's mechanical engineering department, says: ''We are reaching a point where there are no choices available to us. What are we going to do in 10 years' time? We are going to have electric cars. We are going to have desalination plants in every capital city. These are huge new demands that are not yet on our electricity system. ''Nuclear energy requires carbon dioxide production during mining and construction, but after that it's really zero.'' Proponents of nuclear power say it is the only way to provide baseload power for a growing economy and meet climate change targets. But in July three high-profile supporters gave up the cause. Hugh Morgan, Ron Walker and Robert de Crespigny applied to deregister their company, Australian Nuclear Energy, in recognition of the Government's hostility. It had been set up in the last years of the Howard government, as the prime minister appointed former Telstra chief Dr Ziggy Switkowski to head an inquiry, which came down in favour of a domestic nuclear power industry.

Morgan says he believes Australia has left itself vulnerable to a future energy supply disaster by placing its hopes in unproven carbon capture and renewables: ''If you need high-voltage electricity to maintain any significant industry in the country you need regular baseload power that they can rely on in 20 or 30 years. That is the umbilical cord to everyone else's industrial investments.'' He says 450 new nuclear plants are planned or under construction globally, which will double the existing number of plants. But he fears even if Australia wanted to start building, because of global demand it would be way behind in the queue. There is one Labor identity who has spoken out in support of an Australian nuclear industry. National secretary of the Australian Workers' Union Paul Howes says most of the opposition to nuclear power is seemingly from older people influenced by the Cold War nuclear disarmament movement. ''People are worried about nuclear waste, but they are only now beginning to consider the environmental costs of coal,'' says Howes. ''There are new generation reactors being developed which will largely eliminate radioactive waste. They say nuclear is more expensive, but it becomes cheaper than coal when we add a carbon price as well as the costs of carbon capture.'' Indeed, energy production has social costs that the independent Australian Academy of Technological Sciences and Engineering tried to quantify this year that are not included in any wholesale price. These include effects on human health, climate and crops. ''Combining greenhouse and health damage costs for Australia gives representative total external costs of $19 a megawatt hour for natural gas, $42 a megawatt hour for black coal and $52 a megawatt hour for brown coal,'' the academy says. These ''external costs'' were found to be much lower for renewable and nuclear energy: from $1.50 for wind power, $5 for solar photovoltaic and up to $7 a megawatt hour for nuclear energy.

IT IS a sparkling, blue-skied day above the hills of Toora, near Wilsons Promontory. From a distance the green ridges seem to have been colonised by a troupe of baton twirlers, as the blades of the wind farm respond to a rising south-westerly. It is about 100 metres to the tops of the blades, prompting critics to lament the industrialisation of the landscape. Still, wind is the most practical of renewable sources right now, clean and cheap. Victoria has approved wind farms up to 2000 megawatt capacity (one megawatt equals 1 million watts, roughly enough to power 400 homes a year), with another 2500 megawatts in prospect, but since it is an intermittent resource, wind delivers only a third of its nominated capacity. If fully deployed, Victoria's water desalination plant will consume 92 megawatts. To compensate, AGL will build a wind farm of more than 300 megawatt capacity. With more than 150 turbines, Macarthur will dwarf Toora's 12 turbines, but wind energy is only ever a top-up to baseload power. In Europe, particularly Germany, Denmark and Spain, experience has made energy authorities reinforce wind energy with baseload coal or nuclear up to 90 per cent of their potential. Martin Ferguson adds that solar photovoltaic energy - which converts sunlight directly to electricity - is not a renewable energy answer.

Solar thermal energy may hold more potential. A German company, Solar Millennium AG, has built several solar thermal plants in southern Spain that, by storing heat during the day, can run at full power for 7½ hours after sunset. ''Now that we have thermal storage it is no longer true that solar energy is not a baseload electricity source,'' says Diesendorf. Solar Millennium is looking to Australia for expansion through the Federal Government's Solar Flagship program, but its existing plants are, at 50 megawatts, less than one-thirtieth the capacity of Hazelwood. The solar cause also suffered a huge setback last month when Australia's leading solar energy developer, Solar Systems, which was to build a 154-megawatt power station in Mildura, went into liquidation. The persistent doubt is that renewables may not economically deliver sufficient capacity to replace existing power stations. Nuclear power, which does provide baseload power stations of similar capacity to coal, continues to be deeply opposed by many Australians. A poll conducted this year by the Uranium Information Centre found the 40 to 55 years age group most trenchantly opposed to nuclear power. This is the generation that grew up in the shadow of the Cold War; that experienced the anti-nuclear movement of the 1970s; that witnessed Chernobyl and the breakdown of the Three Mile Island reactor in Pennsylvania, overlaid with cultural influences including films such as the apocalyptic Dr Strangelove and the nuclear industry conspiracies The China Syndrome and Silkwood.

In the face of climate change, younger people are less resistant. However, the climate change threat has not diminished opposition from veteran anti-nuclear campaigner La Trobe University professor Joseph Camilleri. ''I don't think we have anywhere near a fully fledged, widely accepted, long-term system of waste disposal. Until and unless that comes through … to be thinking of a substantial expansion of the industry is foolhardy,'' he says. Equally pertinent, he says, is that while nuclear power, in theory, may help counter climate change, in practice it is problematic. The reality is the sizeable expansion of nuclear energy would take place in parts of Asia and Latin America, which may not meet the operational and waste-handling challenges. There would be serious questions about ''the technical, regulatory and other requirements, and whether on grounds of safety, waste disposal and proliferation they would be able to meet the standard that we currently accept in most parts of the industrialised West'', Camilleri says. But so-called fourth-generation nuclear reactors, which yield much more power with less nuclear fuel, actually consume large amounts of their own dangerous waste. Some have already been successfully tested in pilot plants. Neverthless, Mark Wakeham, director of Environment Victoria's anti-Hazelwood campaign, says political and practical obstacles such as the long construction time for nuclear plants, stand in the way. ''It takes decades and we don't have decades,'' Wakeham says. ''Every proposed nuclear power plant in the last two decades internationally has delivered over budget and has been significantly delayed. Our view is it's inherently problematic. It's a very large consumer of water so there's very few locations that you could actually site a nuclear power station in Victoria. Basically it would need to be near Port Phillip Bay or Western Port Bay, and if you reckon it's hard to get a wind farm constructed in Victoria at the moment, try building a nuclear power station.''

Monash University's Price, who has worked as an engineer in the UK nuclear power industry, says that the public perception in Australia is at odds with reality. ''[Nuclear energy] is a great deal cheaper than wind power and solar power, though is more expensive than brown coal,'' Price says. ''There have been very few large accidents. In fact, only Chernobyl stands out, and that is not a reactor system that would have been approved in the West. The other reactor systems have all had terrific records.'' Although the Federal Government remains resolutely anti-nuclear, it has an agency that is quite the reverse. The Australian Nuclear Science and Technology Organisation (ANSTO) runs Australia's only nuclear plant at Lucas Heights in Sydney's outer south-west, the 20-megawatt OPAL reactor, a joint German-Argentinian design that opened last year. (Lucas Heights was founded in 1958 in the early stages of the Cold War by the Menzies government with a 10-megawatt reactor, which was mainly used for nuclear medicine.) HEAD of ANSTO Ziggy Switkowski believes that in its opposition to nuclear power Australia is alone among developed countries committed to deep greenhouse reductions. ''Australia stands alone in claiming that we are different, that we have a whole range of alternatives that in combination will get us to our target. It is ambitious but the numbers just don't work,'' he says. ''[We must] provide for the next generation of baseload electricity generation with clean energy. The only way to do that is with nuclear power. There is no other alternative. ''If we accept we want to move to a carbon-free economy by 2050, while there will be contributions from solar, wind and geothermal, the largest driver of that transition globally will be nuclear power. I don't think the case can be made that Australia is different, because we are not.'' CSIRO's Lincoln Paterson says he is no advocate for the nuclear industry, but even accounting for the Chernobyl tragedy, nuclear is relatively low risk considering 6000 or so people die annually from coal mining in China.

''There is a risk with nuclear, but there's a pretty horrendous risk if we do nothing,'' Paterson says. ''I've flown in and out of Bangladesh and there are 160 million people within 10 metres of sea level, and you start wondering what's going to happen to them. ''Wind by itself can't do it. Carbon capture and storage by itself can't do it. Nuclear by itself can't do it. It's going to require all of those technologies to make a contribution, and that's going to depend on where you are in the world and what the particular attributes of your country are.'' It is, Camilleri says, one of the most serious challenges humanity has faced in the past several hundred years, calling for extraordinary political and technical responses. And we are not there yet.