Keeping the power stable even for one household requires batteries, so once again we have the contamination problem back. Interesting, has a lot of potential, but the big problem is that it destroys the view from the beaches and would most likely destroy the ecosystem of the ocean around it. Well, as long as the fuel is hydrogen, then this is a clean alternative. But again, the fuel cells are expensive to build, and the hydrogen fuel isn't real cheap to generate either. Plus there is that public fear of hydrogen.
Most people immediately think of the Hindenburg explosion.
Ignoring the fact that it would never have gotten off of the ground, if the Hindenburg had been filled with gasoline instead of hydrogen, it would have flattened everything for miles. So, basically what I am saying is quit bitching about what nuclear, hydroelectric and coal do to the environment and devote all of your misspent effort and money to finding an alternative that is cheap, clean and actually works for mass generation. But do keep them from drilling for oil in Alaska. We aren't that desperate for oil. This screen saver searches for extra-terrestrial signals during a time when you wouldn't be using your CPU anyway.