Collecting solar power on the moon and beaming it by microwave back to Earth is about as efficient as buying a cray supercomputer in order to generate enough heat from it's electronics to use as a water heater in your home. There's absolutely, positively no reason to spend MY money (which is what they mean when they say tax dollars) putting anything at all on the moon.
As far as power generation goes, the most powerful electric generation station in the world is the
Three Gorges Dam, slated to be fully operational and producing 18Gw of electricity by 2009. If we can do all that just with water coming down a river, I'm quite sure there's no reason to go to the moon for any reason.