I wonder why they are bothering with gallium-arsenide panels when using a solar thermal setup would be a lot more cost efficient and probably more energy efficient as well. You simply run some kind of coolant through the collector, exchange the heat into water, and run a steam turbine from the resulting steam. You can even collect the water afterwords and condense it to get distilled water. There are many power plants that run on that principle, but it would be cool to see something that can be mounted in the back yard. And the materials necessary are very common and cheep, so the entire product could be much cheeper as well.