But it is not just corporations that are finding that bigger may be better.

Hull, Mass., is about as far from an oil or gas well as it is possible to get in the United States. Its municipal utility decided in the early 1980s to build a wind turbine, making an asset from the strong breeze coming off the ocean north of Boston. The machine it built could generate 40 kilowatts, enough for a handful of homes.

Five years ago, Hull tried again, still wanting to cut energy costs and also the emissions of greenhouse gases that might one day cause the Atlantic Ocean, which surrounds the town on three sides, to creep up the beaches. It built a wind machine 16 times larger, 660 kilowatts. While the 1985 turbine was on a structure that looked a bit like a ham-radio operator’s antenna, the new one, named Hull 1, was on a 150-foot tower.

But it was too small. Last year the town installed Hull 2, which at 1.8 megawatts is three times larger. Now Hull is considering four new turbines that can produce 3.6 megawatts each. “The small one we have, purely aesthetically, is kind of an ugly thing,” said John B. Murdock, manager of the municipal electric system. With their slow-moving, graceful blades, he said, “the big ones are much more attractive.”

They also make better economic sense, he said. Earlier this year, the town put up a tiny turbine, 1,800 watts, as an educational tool, for $15,000. If 1,000 families in the area put up such machines, they would have the same output as Hull 2, at a cost of $15 million. Hull 2 cost about $3 million.

Hull’s economics are being repeated around New England and the world. Farther down the Massachusetts coast in Nantucket Sound, for example, entrepreneurs are trying to build the Cape Wind project, 130 turbines producing 3.6 megawatts each.

At Siemens Power Generation, which builds equipment for wind turbines and other generators, Randy Zwirn, the chief executive, said that the only limit to wind-turbine size might be how long a blade could be transported to the site. The company’s 3.6-megawatt machine uses a blade that is about 175 feet long.

Other companies want to build even bigger wind turbines with capacities as high as seven megawatts. A larger machine would be even higher — perhaps 250 feet — and could take advantage of the fact that winds are 20 percent stronger at 250 feet than at 150 feet, said Dr. Mark Z. Jacobson, an associate professor at Stanford’s department of civil and environmental engineering.