...Dr Diesendorf agrees.
"There's been a lot of nonsense talked about, in Australia and elsewhere, about renewable energy allegedly not being able to provide baseload power, not being able to substitute for coal," he said.
"That's never been true. It's even untrue with regard to wind power, and now with solar thermal power, it's certainly untrue."
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.
"We think we can move much faster than nuclear and on an unsubsidised basis, we will be cheaper than nuclear power, and we should be cheaper than IGCC [integrated gasification combined cycle] coal-based power generation," he said.
Dr Mills says big solar plants will be able to replace nuclear and fossil fuel-fired plants in the US.
"In five years time, we'll have very large plants and I would say gigawatt-style plants already commissioned, able to run 24 hours a day and completely replace the function of nuclear and coal plants," he said.
) using a Stirling engine?
