U.S. energy grid gets its first taste of tidal power

A company called Ocean Power Technologies has come up with a tidal power generation in a familiar shape: a buoy. Now, after months in the water, the PowerBuoy has been hooked up to the energy grid, making it America's first tidal energy generator.

Instead of relying on the back-and-forth motion of the waves, it uses the up-and-down swell and fall of the ocean to generate energy. It'd be awesome if we could just replace every buoy out there with one of these things, but getting the energy back to shore is the tricky part.

The PowerBuoy is right now lending its renewable power to a Marine Corp base in Hawaii, though Ocean Power Technologies plans to bring a utility-scale tidal farm to Oregon.

It's an interesting first step for tidal power in America, where hydroelectric plants are already an established standard in the country.

This is a unique idea, I suppose, but would it be efficient and realistic compared to hydro power plants (those aren't tidal though) and other similar methods?

So we could just plop a massive piece of crap into the ocean and the gravitational energy would equate to free energy? :\

Though an advantage that I see for this method is that it doesn't need to be done anywhere too specific, and set-up would be fairly easy.