Internet search engine giant Google announced Tuesday that it is investing in a mammoth project to build an underwater "superhighway for clean energy" that would be able to funnel power from offshore wind farms to 1.9 million homes without overtaxing the already congested mid-Atlantic power grid.

The project, dubbed the Atlantic Wind Connection, calls for spending as much as $5 billion to create a 350-mile network of underwater cables stretching from northern New Jersey to Virginia. It would eliminate the need for offshore wind developers to build transmission lines of their own, easing what can be a barrier for such projects.

Google is partnering with Good Energies, an environmentally focused international investment company based in New York, London and Switzerland, and Tokyo-based Marubeni to finance the project. The project is led by Trans-Elect, an electric transmission company in Chevy Chase.

Bob Mitchell, chief executive of Trans-Elect, said at a news conference that the venture constitutes "a huge, huge bold project" that would "stimulate development that is otherwise impossible" offshore along the East Coast. The grid would transmit 6,000 megawatts of offshore wind energy.

Rick Needham, director of green business operations at Google, cautioned that the project is in its early stages but said, "we're willing to take calculated risks on large-scale projects that can move an industry." He added, "It provides a smart, scalable platform for future expansion."

Although several offshore wind farms are in development along the East Coast, none is operating. Some, such as the Cape Wind project, which won federal approval in April, have encountered fierce local opposition on aesthetic and environmental grounds. Others face bureaucratic hurdles.

The Obama administration has identified offshore wind development as top energy policy priority, and administration officials have vowed to ease the way for wind farms off the East Coast.

"By identifying high-priority areas offshore for potential wind projects, we can explore the development of a transmission backbone in the Atlantic Ocean to serve those areas," Interior Secretary Ken Salazar said last month. "Rather than develop transmission infrastructure plans on a piecemeal basis, we should - in close coordination with the private sector, states and tribes - lay out a smart transmission system up front."

John Breckenridge, managing director of Good Energies, said at the news conference that the grid would fix "a lot of what's been done wrong in the renewable energy industry generally," where offshore wind projects have been planned "in a haphazard way."

The transmission line would address the problem of wind's intermittent supply by tapping into a much broader swath of the coast to meet consumer demand.

While the project is outside of Google's normal focus, officials said, "We believe in investing in projects that make good business sense and further the development of renewable energy."

Google will provide 37.5 percent of the equity for the initial development, in which officials hope to obtain the approvals required to begin construction, according to Jamie Yood, Google spokesman. The New York Times, which first reported the project in its Tuesday print edition, said Google's initial investment in the project will be $200 million.

Mitchell said Trans-Elect hopes to begin construction in 2013 on what it calls a "backbone transmission project." He said they hope to complete it by 2020, although an initial stage should be finished and operational by 2016.

Consumers who would receive electricity through the grid would help fund the project, Mitchell added, although he said at this point, "It's hard to say what will be the impact on the consumer."

The mid-Atlantic is ideally suited for offshore wind technology, the project's backers said, because the water remains relatively shallow 10 to 15 miles offshore - far enough out so that the wind turbines would be barely visible from land. Mitchell said that could address the "visibility" issues that have plagued the Cape Wind project on Nantucket Sound.

Staff writer Debbi Wilgoren contributed to this report.