New York City could become the grounds for a new kind of urban wind farm if a Cleveland-based mechanical engineer has his way.

Cleveland State University's Fenn College of Engineering on Thursday said it will unveil a new wind turbine design by one of its professors, Majid Rashidi, that could attach to the sides of the water storage tanks that sit on the rooftops of many city apartment buildings.

Mayor Michael Bloomberg, who has made green programs a centerpiece of his administration, last August proposed crowning the city's bridges, skyscrapers and shorelines with turbines, but critics said they would be impractical and possibly hazardous.

But Rashidi said his turbines solve a key stumbling block of harnessing wind power effectively in crowded urban areas because they accelerate the flow of wind through four rotating turbines. That allows the turbines to work where the wind speed otherwise would be too low.

In the urban settings, usually because of the existence of buildings, you don't get the high speeds needed, he said.

The turbines, which are fixed to the sides of a cylinder, already seem to be outpacing a competing turbine that sits on a traditional mast.

Today, I saw on the roof, my four were all rotating; the one stationed on the mast was not moving, so proof of the concept has already been shown, Rashidi said.

Rashidi's concept takes advantage of the city's existing water towers that were designed to hold thousands of pounds of water and thus could handle any forces the turbines exert, said Richard Steiner, who is working with Rashidi.

Rashidi's four turbines could produce 8 kilowatts per hour. That compares with the 2,000 or so kilowatts produced by the much bigger turbines that sit atop tall masts.

The Cleveland Indians baseball team is expected to be the first to install the turbines at its home stadium.

Steiner said he hopes the team will agree to use them for its Progressive Field stadium within 30 to 60 days.

Bridgett Neely, an energy expert for New York City, said that by late summer the city hopes to clarify how it can encourage the use of wind turbines by smoothing permitting and testing.

Like many U.S. cities and towns, New York's zoning and other rules could block rooftop turbines -- as well as smaller models the Cleveland experts hope homeowners could use in their backyards.

New York is likely to start with smaller turbines. Last year, the ones that made the biggest splash in print, on buildings and bridges, some of that was fanciful, Neely said.

She said wind turbines were just one item on Bloomberg's green energy list, citing six experimental turbines in the East River and a possible city-state offshore wind farm.

One promising green model is the city-owned Brooklyn Navy Yard's test of street lamps that run on solar and wind power, a useful feature in the Northeast where clouds can persist for days, according to Baldev Duggal, who invented the Lumi-Solair lamps.

The Navy Yard, now an industrial park, could reap savings of hundreds of thousands of dollars because of the new lamps' lower costs. Each lamp has its own power, so no underground wires have to be dug up when they short out.

The Cleveland professors also are exploring using a helix shape to hold the turbines instead of a cylinder. We want to make it smaller and even get more acceleration, Steiner said.

The swiveling arm and supports for the Cleveland turbines might cost somewhere in the neighborhood of $5,000, Rashidi estimated. Then you have to buy off the shelf turbines and just hang them up like a chandelier, he said.

Critics of windmill farms say they kill birds because they often are located in migratory routes.

But the Cleveland experts say the much smaller turbines lack the killing force of the wind farms. Those much bigger turbine blades can weigh over 2,000 pounds.

(Editing by Leslie Adler)