By most measures, wind energy has been a great business lately.

The U.S. wind energy industry shattered previous records in 2008 by installing 8,358 megawatts (MW) of new generating capacity, and did even better in 2009, building out another 9,922 MW. That's enough wind power to deliver electricity to 4.4 million homes, according to the American Wind Energy Association.

But if you think it's easy -- or cheap -- to get wind-powered electricity to places where it's needed, talk to Tom King.

As the executive in charge of the U.S. business of National Grid, a global utility company with extensive operations in the Northeast, King would like to see wind turbines built off the coast of New England, as well as along a wind belt that stretches across the northern border of New York and runs east through Vermont, New Hampshire and Maine.

"When you look at the Northeast," King says, " it's bracketed by some very significant wind resources."

The trouble is, the wind blows offshore and up north, and the demand is in cities like New York, Boston and Providence. Connecting the supply with the demand is one problem. Cost is another.

King and I met this week in Washington to discuss wind. National Grid, the biggest utility company that most people don't know, is a London-based firm that dates back to 1990, when the U.K. privatized its electricity system. Since then, it has become, through acquisitions, one of the largest utility companies in the U.S., with about 8 million customers, nearly all in regulated markets. National Grid serves all of Rhode Island, nearly half of Massachusetts, roughly 20 percent of New York and a smaller number of customers in New Hampshire. Revenues topped $24 billion last year and it has about 27,500 employees, nearly two-thirds in the U.S.

National Grid has taken strong policy positions backing climate change legislation in the U.K. and the U.S. It has also promised to reduce its own greenhouse gas emissions by 80 percent by 2050. And the company supports renewable energy, says King.

"It's a key element of reducing carbon emissions," he says. "It's a matter of national security. It creates jobs and economic development."

Which all sounds great. But National Grid's efforts to support the offshore wind projects in New England reflect some of the challenges facing wind power. While the company doesn't develop projects, as the local regulated utility, its willingness to buy electricity from the projects is key to their viability. So National Grid has been negotiating deals–known as Power Purchase Agreements, or PPAs, with Deepwater Wind in Rhode Island and Cape Wind in Massachusetts.