Jay Leno, the host of “The Tonight Show,” recently installed a prototype wind turbine (as well as solar panels) atop a garage in Burbank, Calif., where he works on his car collection. He senses public interest in small-scale wind power that does not have much to do with dollars-and-cents analysis.

“People seem fascinated by the turbines,” Mr. Leno said. “You go, ‘Look! It’s spinning!’ ”

Perched high above a building, wind turbines serve as a far more visible clean-energy credential than solar panels, which are often hard to see. At least a dozen small manufacturers have sprouted up to supply the market, though rooftop turbines still account for only 1 percent or so of the 10,000 small wind turbines that are sold each year in the country, according to Ron Stimmel, an advocate of small wind systems at the American Wind Energy Association.

Image One of two 6-foot-tall turbines atop the garage roof of Chris Beaudoins San Francisco home that will be hooked to the power grid. Credit... Noah Berger for The New York Times

That number seems poised to grow, given the recent interest.

“We’re prebleeding-edge early,” said Todd Pelman, founder of Blue Green Pacific, the maker of Mr. Beaudoin’s turbine. The technology, he conceded, is not yet “something that would be bought at Home Depot.”

Mr. Pelman has sunk $200,000 of his own money into the start-up, which has just three turbines in operation — Mr. Beaudoin’s pair, and one above Mr. Pelman’s own bedroom in a Victorian house in San Francisco.

In accordance with urban sensibilities, many of the new designs are stylish. The six turbines peeping over the edge of a building in the Brooklyn Navy Yard, installed this summer, look as if they are covered with dainty white parasols, a design touch that doubles as a bird shield. The French designer Philippe Starck has plans to introduce an elegant plastic turbine in Europe this fall.

Mr. Bloomberg’s proposal calls for wind turbines on the city’s skyscrapers and bridges, though it is unclear how big they will be and just where they will go.