A gust of demand for green energy in Minneapolis has helped power the proliferation of wind farms on the state’s rural horizon.
A recent city report noted nearly 6,300 utility customers in Minneapolis participate in Xcel Energy’s Windsource program, which supports wind farms in Southern Minnesota.
And for residents interested in obtaining wind power, Windsource is for now about the only option. Wind turbines are banned under current zoning rules from anywhere but industrial districts in the city.
But a growing list of small wind products is fanning interest for generating wind power in urban areas.
Chicago and San Francisco are among the first cities to permit small turbines within city limits.
This month, the City Council will consider an ordinance by Council Member Cam Gordon (2nd Ward) that would allow the conditional use of wind turbines in much of the city.
The city’s Planning Commission approved the motion April 23, and city planning staff has recommended the City Council approve the zoning code amendment. The item is on the Planning and Zoning Committee’s agenda for May 17.
Gordon said the change could encourage innovation by letting residents experiment with new wind products. And if they work, everyone would benefit from the resulting reduction in air pollution and greenhouse gases, he said.
“People are interested in trying … alternatives, and they don’t have a chance to do that right now if they’re in Minneapolis,” Gordon said.
The proposal has been met with skepticism from an unlikely source: the nation’s wind energy industry association, which says the city lacks the wind for effective power generation.
“It’s akin to saying, well, hydropower is good for society, so let’s put a hydropower facility on Basset Creek,” said John Dunlop, senior technical outreach engineer for the American Wind Energy Association. “Basset Creek doesn’t have the hydropower potential that you need to run that generator. There’s no resource there. It’s the same situation with wind energy (in Minneapolis).”
Most turbines generate little or no electricity at wind speeds at or below 3.5 meters per second, Dunlop said. A 2006 study commissioned by the Minnesota Department of Commerce found that at 30 meters up, wind speeds in the Twin Cities average about 4.3 meters per second.
That means turbines here would sit stagnant about half the time, Dunlop said, and he worries what that could do to wind energy’s reputation.
“I think from a public policy standpoint, you’re doing yourself a disservice to set yourself up for failure that would impact people’s opinions about wind power in general.”
Gordon admits existing wind technology might not thrive in most of the city, but he believes the industry is inventing new products that require less wind and are a better fit for cities.
“I’m not sure if we’ll have people knocking on our doors right away, but I just think the technology is right on the edge. This is a way to open it up. If we wait longer, we’re just going to be relying more on fossil fuels,” Gordon said.
Under his ordinance, property owners with at least an acre of land would be able to erect freestanding wind turbines. Off-limit areas include parks, cemeteries, Downtown, the Shoreland Overlay District and the Mississippi River Critical Area Corridor.
Building-mounted turbines not exceeding 15 feet in height would be allowed in all parts of the city except the Shoreland Overlay and Mississippi River districts. Residential buildings would need to be at least four stories tall to qualify.
Ron Stimmel, small-wind advocate for the American Wind Energy Association, said results in urban areas have been mixed in part because their density makes it difficult to locate quality sites.
It’s not as simple as sticking a turbine on top of a skyscraper. Turbines can cause structural damage to buildings, and most [structures] aren’t designed to sustain the constant vibration from turbines. There are also noise and safety considerations.
Generally, wind turbines require about an acre of space in which they are at least 30 feet higher than any obstructions, Stimmel said.
“It gives the wind an ability to stretch its legs and get up to speed,” Stimmel said.
The taller the better because the amount of power generated increases exponentially with wind speed, which increases with altitude.
Annie Young, commissioner on the Minneapolis Park and Recreation Board and a wind-energy proponent, said she thinks there are areas in the city where even existing wind turbines would be effective.
“I would say there’s got to be some sort of wind,” Young said. “Stand on the corner of Nicollet Mall and 8th Street and [ask] why can’t you get something that would churn in all that wind?”
The reason is turbulence, Stimmel explained. Wind power generation requires not only high-speed wind, but also high quality. When a wind gust hits a building edge, “it’s like a wave crashing into the shore.” The force scatters and becomes more difficult to harness.
The majority of public feedback filed with the Planning Commission before its vote focused on concerns about wind turbines’ possible impact on birds. As a result, the commission decided to keep the turbines away from the city’s waterways.
“Wind generators have been known to be really hard on birds,” said Mark Martell, director of bird conservation for Audubon Minnesota. “The big propellers really confuse birds. They don’t seem to get them. They just don’t see those turbines moving.”
Continuing to ban wind turbines from the Shoreland Overlay District and Mississippi River Critical Area Corridor address his initial concerns, though he had not reviewed the ordinance.
“We really like the idea of alternative energy sources, but we want to be careful where they’re put,” Martell said. “The river is a real highway for birds.”
Lara Norkus-Crampton, a planning commissioner from Southwest, said she thinks what the Board approved, and what the City Council will soon consider, is a reasonable proposal.
“I’m hoping that this is just the beginning of a conversation,” she said, “of how we can, where appropriate, encourage renewable energy production in the city of Minneapolis.”
By Dan Haugen
8 May 2007
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