In an announcement that could jump-start offshore wind development along the Atlantic seaboard, Google and investment firms Good Energies, New York, and Marubeni Corp., Tokyo, said Oct. 12 that they are backing the development of a 350-mile underwater high-voltage DC transmission line from of Northern New Jersey to Norfolk, Va.

The line, being developed by Chevy Chase, Md.­based Trans-Elect, would provide a transmission backbone linking several different offshore wind farms off the coasts of Virginia, Maryland, Delaware and New Jersey, and add up to 6,000 MW to the Atlantic grid from wind farms. Construction of the first phase of the line, from northern New Jersey to Rehoboth Beach, Del., is estimated to begin in 2013, cost $1.3 billion and be complete by 2016. The total project, in five segments, is expected to cost more than $5 billion and would be complete sometime after 2020.

The transmission line could prove a catalyst for offshore wind. While the U.S. Department of Energy has estimated that 54,000 MW of electricity from offshore wind could be developed by 2030, not a single offshore wind turbine has yet been installed in U.S. waters. According to DOE, 54,000 MW of offshore wind could create more than 43,000 permanent jobs.

Without the single line, each offshore wind developer would have to build its own transmission and connection to shore. Bob Mitchell, CEO of Trans-Elect, said in a news conference that the line would save offshore wind developers 17% to 20% per project. Mitchell says that without the project, only a few offshore wind farms would be built. He says that the line would help the Mid-Atlantic states reach their collective goal of 13,000 MW of renewable energy in coming years.

"The U.S. will require large investments in its electric transmission grid to meet its renewable and energy independence goals," says Richard Straebel, executive vice president of Marubeni Power, which manages investments. "Over the past few years this sector has been an increasingly important part of Marubeni's U.S. power market activities and we are very excited about our role in this strategic and transformational project."

Mitchell says Trans-Elect would use existing HVDC technology to build the line, but that it would push the limits of that technology by having several onramps and offramps onto the line. DC lines can carry electricity for hundreds of miles with little or no loss of electricity, but they typically can have only one onramp and one offramp. Mitchell says that a new, patented technology will allow the line to pick up electricity from several wind farms and deliver it to multiple spots along the coast. Wind farms would feed electricity into the line from platforms, essentially substations, which will convert the AC electricity to DC. Mitchell says Trans-Elect has had discussions with one of the few HVDC transmission cable suppliers, but would not reveal the company's name.

Rick Needham, director of Google's green business operations, called the project a superhighway for offshore wind farms, and one that would intelligently expand the region's renewable grid. Needham says that Google's investment, about one-third of the development start-up costs, was a "calculated risk" that offered Google attractive returns.

John Breckenridge, of the investment group Good Energies, says that much of the development of renewable energy in the country had been built haphazardly. "We saw this project a representing a fix to what has been done wrong," in developing renewable energy in the country. "This project allows us to do this in a planned way and optimizes," the developments of renewable energy.

The line is planned to connect to the shore in areas where there is extra transmission capacity to handle wind power, and where fossil-based generation can provide back up, or reserve, generation for the intermittent wind power. The transmission line could also be used to carry conventional land-based power up and down the coast, where transmission system is already constrained.

Ratepayers will pay the cost of the line. The Federal Energy Regulatory Commission and PJM Interconnection will separately have to approve the rates for the projects. Trans-Elect expects to file with FERC late this year or earlier next year.

Trans-Elect must then receive approval from several different federal and state agencies, including the Bureau of Energy Management, before construction can begin.

Mitchell says that after the initial phase of the development is completed, Trans-Elect expects to be able to finance the rest of the project through debt. The partners in this initial phase of development may chose to continue to provide financing for the project.

"This is a 10-year plan," he says. "We're not approaching this as something that can be done overnight."