The U.S. may finally get a unified power grid

It is a decades-old dream: a single, vast North American electric grid, from the Atlantic to the Pacific, from Mexico to the Arctic Circle. Such a continent-wide supergrid would let officials transmit the tens of gigawatts of wind-generated power from the Great Plains to cities on both coasts. It would let Pacific Northwest hydropower flow to Chicago and let Texas wind power find its way to Massachusetts, Mississippi, and Montana. The benefits, measured in financial and reliability terms, would be fantastic. And yet despite many studies and even several attempts to create such a grid, it has never been achieved. The technology and the political will have been lacking.