Ocean Renewable Power, a Maine-based tidal power company has a cover on Popular Science. (Yes, I did not realize the still produced Popular Science either)

It is kind of cool.  Their turbine uses thingers that spin and make power regardless whether the tide is coming in or going out.  Last year Ocean Renewable installed one of these in Cobscook Bay near Eastport, Maine and connected it to the power grid, providing enough electricity for about 25 homes. The pilot program calls for more units to be installed off eastern Maine, providing enough power for more than 1,000 homes.

Being a nerdy tree-hugger, I think I need to get a copy of this issue of Popular Science. It focuses on five technologies that could help the nation reach energy independence. Science is so cool.