I just heard about that this morning listening to the radio. An interesting concept, using heat generated by the sun not the classical photovoltaic means to produce electricity.
Think of it as a humongous magnifier (in this case hundreds of mirrors pointing all in the same direction) that will use sun rays to heat water and produce electricity, while the traditional photovoltaic way uses photons to extract electrons from atoms and create electricity out of it.
I thought this was pretty cool not only because it’s "Green" but because it could help solve the positive feedback loop*: global warming => hotter seasons =? need more air conditioning => need more electricity => more greenhouse gas => more global warming.
Indeed, in this situation we could have a self-stabilizing system where more heat => more clean energy => more air conditioning without more greenhouse gas.
* "positive" feedback loops means the output reinforce the input creating a very unstable system (like a water leak widening the crack through which it comes) vs. a negative feedback loop where the output correct the input bring the system to a equilibrium (such as the air slowing down a moving object as it goes faster)