Five foundations are set after an inaugural construction season for what will become the first commercial offshore U.S. wind farm, developers said. Deepwater Wind, one of the developers behind the Block Island wind farm off the coast of Rhode Island , said five steel platforms are now installed . The project should yield 30 megawatts of electric power, powering the 17,000 homes on Block Island, 12 miles from the mainland, that currently use diesel fuel for electricity. Excess electricity will be carried to the mainland by cable. The turbines will be 589 feet above sea level, making them among the tallest in the world. […]