redOrbit: On Tuesday, a plan to build the United State’s first offshore wind farm took another step forward, after the Massachusetts Department of Environmental Protection approved its proposed undersea cables to transmit power to the mainland. The state review found that the Cape Wind project, which would place 130 turbines about 4.7 miles off upscale Cape Cod, would provide “greater public benefit than detriment.” The wind farm would provide enough power for about 400,000 homes, but is …