The Technology Review has a nice article about large offshore wind turbines, located out of sight, over the horizon, that may overcome the NIMBY-ism that is limiting efforts to deploy wind turbines within vision of the shoreline.
GE is partnering with DOE to develop 5-7 megawatt wind turbines by 2009. These turbines should make wind power more economical, because the cost of building and installing offshore wind farms depends primarily on the number of turbines, not the size. The new turbines will be mounted to towers rising 90 to 95 meters and will have rotors measuring 140 meters in diameter.
The turbines would be installed where the water depths are up 50 meters, too deep to economically use towers sitting on the sea floor. Instead MIT proposes using "tension leg" platforms that oil companies use for deep-water rigs. The wind turbines and towers would be assembled at a shipyard and placed on top of large floating cylinders ballasted on the bottom with concrete to keep the structure from tipping over. After towing out to sea the cylinder is anchored to the sea floor with cables.
See the entire article for more details.