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Tech Industry

'Micro' wind turbines are coming to town

A handful of start-ups are making mini turbines that go on top of city buildings and turn wind power into electricity. Photos: Harnessing wind

A handful of start-ups are floating an idea that could change the face of the wind power industry.

Rather than build farms of towering wind turbines in rural areas, some companies are designing "micro," or small-scale, turbines that fit on top of buildings. The idea is to generate electricity from wind in urban or suburban settings.

"We want to integrate these small wind turbines on buildings in plain sight," said Paul Glenney, director of energy initiatives at Monrovia, Calif.-based AeroVironment. "We think this can really communicate the generation of clean electricity."

News.context

What's new:
A handful of "micro" wind turbine companies are trying to bring small-scale wind power generation to urban and suburban settings.

Bottom line:
On-building wind turbines are still an emerging technology, but they could fill a viable niche among different products for generating energy.

More stories on clean technologies

In their pitch for the technology, the companies are going beyond satisfying the growing interest in clean forms of energy. AeroVironment, Aerotecture and a handful of other businesses are marketing their turbines not just as power generators, but also as attractive additions to existing structures.

Right now, giant turbines built by the likes of GE Energy and Siemens are still the norm in the wind power industry, and on-building versions are rare. Newcomers are trying different tacks to break into the market. While some such as Clipper Windpower are producing entire devices, others are focusing on providing specific components of a turbine.

"We're tracking over 20 different emerging wind technology companies in our proprietary deals database, and that list keeps growing," said Robert Day, a partner at Expansion Capital Partners which specializes in clean technologies.

Overall, the wind industry is booming, experts said. The American Wind Energy Association said that last year 2,500 megawatts of new generation equipment were installed in 22 states, valued at $3 billion.

Wind architecture
AeroVironment, which is perhaps best known for its unmanned aircraft technologies, has a project under development from its Architectural Wind energy technology division.

The turbines look like large fans in square housings. They are specifically designed for placement on the top of steel-reinforced, flat-roofed commercial buildings such as a warehouse or "big box" retail store like Home Depot, Glenney said.

The turbines can be lined up next to each other to aggregate power generation, and the fans will spin even in a very slow wind of a few miles an hour.

micro wind turbines

The company has set up a few beta sites to test various factors, including its cost-effectiveness, the amount of noise it generates, and the potential impact on birds and bats (the turbines have a grate on both sides).

AeroVironment has not yet decided whether to commercialize the products. But in presentations with potential customers, the company has gotten a good reception, Glenney said. Business owners and municipalities are eager to find sources of clean electricity for a variety of reasons, including concerns over global warming and dependence on oil from unstable parts of the world.

"Lots of companies just want to reduce the footprint that a business leaves" on the planet, Glenney said. "And they want to educate their stakeholders--their customers, their pupils--on these issues."

Chicago-based Aerotecture is taking a similar "architectural" approach to wind power generation, although with a substantially different design.

Invented by University of Illinois professor Bil Becker, the company's Aeroturbine product uses a helix-shaped turbine placed inside of a cylinder. The turbines, which are 10 feet long, can be placed in many positions and take advantage of variable wind, according to the company.

"It's not fussy about gusty or turbulent winds. It's very amenable. It's the microclimate of the building that you have to look at," said Lesleigh Lippitt, co-founder of Aerotecture.

The company, which is in the process of commercializing the product, is negotiating with Chicago city officials over an installation at the Daley Center, which would set Aeroturbines at the top of the 650-foot building, she said. Other placements are under discussion, including underneath San Francisco's Golden Gate Bridge, Lippitt said.

Other companies building similar micro wind products for urban or suburban areas include Finland's Windside, and the U.K.'s Windsave and Renewable Devices. There's also a product line called Urban Turbines, from Dutch company Ecofys.

Also on the market are several turbine products, such as Southwest Windpower, designed for remote homes or boats.

Mix and match
Expansion Capital's Day said that small-scale wind technologies have a viable role in the bigger picture of power generation.

Placing a 300-foot high turbine in downtown San Francisco is problematic. But distributed, or on-site, electricity generation systems can help customers get around the transmission bottlenecks and reliability problems of the wholesale electricity grid, Day said.

He added that even small-scale turbines are not immune to the challenges that the overall wind industry faces, such as concerns over noise and cost efficiency.

Wind power also has had some cases of "not in my backyard," or NIMBY, opposition from local residents to construction of large wind turbines. The proposed 420-megawatt Cape Wind project, for example, which would place huge turbines off the coast of Cape Cod, has proved divisive and has not yet been approved.

AeroVironment and Aerotecture argue that their products can enhance the look of existing structures. New "green buildings" could be designed with these turbines in mind to take advantage of the structure's wind dynamics as well, they said.

In terms of usage, an on-site wind turbine would supplement the electricity supply of the building and could be combined with other forms of electricity generation, such as solar panels.

Indeed, Day said that it's unlikely one wind power technology will emerge as a "winner," just as there probably won't be a dominant wastewater treatment or solar technology.

"Eventually, you'll also see some aggregation of these varied technologies by large players who want to be able to offer a full suite of options to meet customers' varied needs," Day said.

Clean technology firms tend to focus on a particular niche because the field is dominated by larger, diversified companies such as GE Energy. And if they are successful, these start-ups tend to get acquired, and don't usually make a stock market launch.

Aerotecture is in its early phases of development as a company, but Lippitt said the idea of micro wind in the city has a lot of potential. "There are more possibilities than rules at the moment," she said.

AeroVironment's Glenney, too, said that the demand for wind power is being fueled by the desire of society overall to have more diversified sources of energy.

"I think this (wind) technology matches up very well with photovoltaic (solar) panels. I think it can be both competitive and complementary," Glenney said. "It's an area that needs more innovation."