Off the coast of Ireland, history was just made. While windpower is taking off, and could soon produce as much as 20% of America's power, harnessing energy from the ocean is still in it's infancy.
But recently Marine Current Turbines successfully completed the installation of the world's first megawatt-scale tidal turbine. And now we've got the first images of the turbine installed to prove it. The 1000 ton SeaGen tidal turbine was secured to the seabed and linked with Northern Ireland's electric grid. MCT will now spend about 12 weeks testing the capabilities of the turbine before regularly feeding power into the grid.
Tidal power has several advantages over wind. The power generation is more predictable (since you always know when the tide will turn) and it is believed that they will have less ecological impacts...since roads do not need to be built to them. There hasn't been enough data yet to determine what affects they will have on marine life.