The Kogan Creek Power Station.The Kogan Creek Power Station.Photo: Kogan Solar BoostAustralian Prime Minister Julia Gillard on Wednesday appeared at giant coal-fired power plant to announce that the Southern Hemisphere’s largest solar project would be built in Queensland.

Why, you may be wondering, would the PM travel to a remote 750-megawatt coal power station to make a big renewable energy news pronouncement?

Well, coal is king in Australia, and the 44-megawatt solar thermal project to be built by Areva Solar at the Kogan Creek Power Station will generate additional steam to drive the coal plant’s turbines.

“By using energy from the sun with Areva’s solar booster application, we will make the coal-fired plant more fuel-efficient and reduce its greenhouse intensity — avoiding the production of 35,600 tons of greenhouse gas emissions annually,” David Brown, chief executive of CS Energy, the coal plant’s owner, said in a statement.

Australia depends on coal to supply about 87 percent of its electricity demand, which gives it one of the highest per capita rates of greenhouse gas emissions in the world. Coal is also a major export, and at any given moment a flotilla of ships sits off the Queensland coast waiting to ferry the fuel to China and other overseas markets.

Despite Australia’s abundant sunshine, the country has been something of a laggard when it comes to renewable energy — which is why a 44-megawatt solar power project is considered a big deal.

In fact, Australia has suffered a green brain drain in recent years as solar entrepreneurs, frustrated with the lack of government support for renewable energy, fled to California.

One of those startups was called Ausra, which developed compact linear fresnel reflector technology that uses rows of long mirrors to focus sunlight on liquid-filled tubes suspended over the arrays. The heat creates steam, which in turn drives standard electricity-generating turbines.

In California, Ausra attracted investment from such prominent Silicon Valley venture capital firms such as Kleiner Perkins Caufield & Byers and Khosla Ventures. But last year the startup was sold to — you guessed it — Areva, the French energy giant and nuclear power plant builder.

Rebranded Areva Solar, Ausra has now come home, so to speak, to Australia.

When I spoke to Areva Solar executives late last year, they were bullish on the market for such so-called solar boost projects like the one at Kogan Creek. But the company also plans to build stand-alone solar power stations to generate 100 percent carbon-free electricity.

Maybe even in Australia.