SAN FRANCISCO — Google Inc. is backing a plan to lay undersea cables to connect proposed windmills off the mid-Atlantic coast, a step the Internet giant hopes will boost wind power as an energy source.
The offshore wind power transmission line would stretch 350 miles from New Jersey to Virginia and could supply enough electricity to serve about 1.9 million households. But the ambitious project, which could cost billions of dollars, faces major hurdles as federal subsidies for construction of wind power installations are set to expire in 2012.
Google said in a blog post that the project would rely on offshore power hubs that collect power from wind farms and deliver it via undersea cables to electrical transmission systems on land.
"This system will act as a superhighway for clean energy," wrote Rick Needham, Google's green-business operations director.
The project could lighten the load on the congested Northeast power grid, Needham said. He noted that the federal government last week approved the first-ever offshore wind development lease for another project.
Needham also called the investment a "calculated risk" as Google looks to promote renewable energy. Google has an initial 37.5 percent interest in the seed stage of the project, the cost of which was estimated by a spokesman at "tens of millions of dollars."
If the project clears regulatory hurdles, the developer will try to raise billions of dollars from private investors.
Google, which is an energy guzzler with its massive computer data centers, has invested in wind farms and buys wind energy as part of its bid to help curb carbon emissions.
It also has solar installations at its Mountain View, Calif., headquarters.
This is not the first time that Google has ventured far afield from its moneymaking core Internet search advertising business. On Saturday, Google said it is developing technology that lets cars drive themselves.