The quickest numbers I could find say that at the scales of large power-plants, the generator is very efficient, but the turbine not so much, around 50%. This would put the system as a whole at around 40% efficency sunlight -> electricity. That's competitive with the best solar voltaic systems tested in the lab, and 50-100% better than practical systems on the market. Assuming their system really does scale up to power plant sizes, of course.
I've never understood how they were able to launch from the moon back towards Earth. Launching from the Earth requires massive infrastructure and huge rockets. Yes, the moon's gravity well is shallower, but still significant.
It's because the fundamental equation that relates a rocket's performance and the mass fuel it requires to orbital velocities is exponential. This makes it work out so that any chemical rocket leaving earth has to have the vast majority of its weight as fuel, where as a rocket leaving the moon only about half of its weight as fuel.
What's more, the entire lunar module and its fuel supply is dead weight as far as the earth launch is concerned, which makes the earth rocket and its fuel multiple all the bigger. Then there's the issue of bringing along enough fuel to slow down the craft into lunar orbit, and escaping lunar orbit back to earth. The lunar lander didn't need to handle any of that, either.
And at the same time, the NSA is the most useless organisation when it comes to fight domestic terrorism, as the only fact related to domestic terrorism they ever uncovered was a money transfer by a San Diego cab driver to a charity in Somalia which is considered a front to a terrorist organisation.
New York... when civilization falls apart, remember, we were way ahead of you. - David Letterman