Thanks to Luke Walker for alerting me to this:
Two of America’s biggest power utilities have unveiled plans for a multi-billion-dollar expansion of solar power supply, backing the argument that solar energy can indeed become a viable alternative to coal-fired electricity.
The company at the heart of the development is Ausra. It was started by Australian solar expert David Mills, who left this country for California earlier this year to pursue the further development of his ground-breaking work.
What makes the announcement more significant is that the utilities are confidently predicting that their solar power will soon be providing baseload electricity – that is, day and night – at prices competitive with coal.
The solar technology developed by Dr Mills already exists here in Australia, in the form of small pilot plants attached to the Liddell coal-fired power station in the New South Wales Hunter Valley.
A plant officer explains that the system’s emphasis is on simplicity, with near-flat mirrors on giant hoops tracking the sun.
“Sunlight, on a clear day like this, strikes those mirrors and is gathered up onto the tower, and there’s an absorber underneath that tower,” he said.
Out comes steam, ready to drive a conventional power turbine. This is on a small scale; the new US company started by Dr Mills and Mr Khosla, Ausra, is now planning plants far bigger.
Dr Mills says the first plant size is more than two square kilometres in area and will generate 175 megawatts of power.
“But really we want to aim for gigawatt-style plants, and they’re much bigger than that,” he said.
The coal and nuclear industries have long asserted that baseload power cannot be supplied by renewable energy. That mantra is oft repeated by Australian politicians like federal Environment Minister Malcolm Turnbull.
“You cannot run a modern economy on wind farms and solar powers. It’s a pity that you can’t, but you can’t,” he said.
Prime Minister John Howard says solar is “a nice, easy soft answer”.
“There’s this vague idea in the community that solar doesn’t cost anything and it can solve the problem,” he said.
“It can’t. It can’t replace baseload power generation by power stations.”
But baseload power supply is just what Ausra is now being contracted to supply for the insatiable US market. It says that within two years it will be able to economically store its hot water for more than 16 hours.
Dr Mills says there is a convenient correlation between humans’ power consumption and the sun’s power supply.
“We get up in the morning everyday, we start using energy, we go to sleep at night,” he said.
“And the presence of the sun, that’s natural. And that correlation means that we can get away with a lot less storage than we might have thought.”
Better than coal or nuclear
Dr Diesendorf says the huge US investment into solar will soon make talk of clean coal and nuclear as solutions to climate change redundant.
“Basically, the solar thermal technology will be on the ground, certainly in the United States and many other countries long before so-called clean coal and nuclear power,” he said.
Mr Khosla says solar power is developing rapidly and will be cheaper than either nuclear power or ‘clean’ coal.