City Proposes Zoning Changes to Accommodate Wind Turbines

City Proposes Zoning Changes to Accommodate Wind Turbines

By Karen Klinger

Could one answer to Cambridge’s future energy needs be blowin’ in the wind?

City councilors think so and have asked members of the planning board to recommend changes to the zoning code that would allow wind turbines to operate under certain conditions throughout the community.

Currently, zoning regulations do not cover wind-driven electricity generators. So far, turbines have been installed in just two locations in the city: on the roof of Harvard University’s Holyoke Center at 1350 Massachusetts Avenue and on top of the home at 14 Clinton Street of Sue Butler, president of the environmental group Green Decade/Cambridge.

But looking ahead to a time when wind power could play a much greater role in generating electricity locally, the Cambridge Planning Board held a public hearing in early June on new zoning regulations aimed at achieving three main purposes:

  • Allowing small-scale generation of electricity for on-site consumption at a business or a residential property such as Butler’s.
  • For the generation of electricity on a larger scale in non-residential areas that could be sold for commercial use.
  • To permit testing and evaluation of wind turbines and to demonstrate their efficacy in urban settings.

The zoning changes would divide the city into areas where wind turbines could be installed for educational purposes without needing a special permit and places where a permit would be required.

The no-permit zones would essentially be limited to the university campuses and a portion of the Boston Science Museum property located in Cambridge. Several restrictions would apply: the turbines would have to be installed on a building and could reach no more than 40 feet above the structure; they would be approved for a two-year operating period, which could be extended; and they would have to be at least 200 feet from a non-institutional residential use.

In the rest of the city, property owners who want to install turbines would need a special permit that would depend on conditions such as their impact on various aspects of the surrounding neighborhood, the extent of the shadows they cast and the level of noise and vibration they generate.

Some rules would affect all turbines, regardless of location: they could not have signs, advertising or cellular phone equipment attached to them; lighting would be allowed only for safety reasons; the cumulative noise they generate would be limited to what is allowed under existing law.

As they discussed the proposals, the planning board seemed to concur with city staff member Iram Farooq that just as wind turbine technology is evolving, regulation of their use in Cambridge is likely change over time. “It’s all sort of beta at this point,” Farooq said.

“We should make determinations as the technology develops,” agreed board member Theodore Cohen.

The board did not vote on the zoning changes, opting to consider them further before sending a recommendation to the city council, which will make the final decision. Assistant City Manager Beth Rubenstein said the council will “likely” take up the issue in September.

Wind Turbines Visible Atop Holyoke Center and Science Museum

In the meantime, anyone who wants to see the kind of wind turbines that may one day be a common sight in Cambridge should go to the corner of Dunster and Mt. Auburn streets and look up to the roof of the Holyoke Center, where six 130-pound turbines about six feet tall can be spotted spinning like pinwheels whenever a breeze kicks up.

One of the curvilinear turbines, made by AeroVironment, also is on display on the ground floor of the building, along with a sign explaining how it works. As the sign says, the three-foot blades of the turbines (which can turn in winds as low as 4 mph) generate direct current (DC) power, which an inverter converts to AC power that is fed into the center’s power grid.

The half-dozen rooftop turbines generate only one kilowatt of electricity each (a kilowatt is 1,000 watts, enough burn ten 100-watt light bulbs). But their modest output is not really the point, said James Gray, Harvard’s associate vice president for real estate.

“Having wind turbines on Harvard’s flagship office building is a major statement about Harvard’s commitment to renewable energy,” Gray told the university’s weekly news gazette.

Butler said her small Clinton Street turbine also is more about making a visible commitment to renewable energy than generating power. “I turn it on if the wind is really blowing,” she said, “but most nights I turn it off,” so as not to disturb the neighbors.

Over at the Science Museum, two wind turbines recently were installed and connected to the electric grid as part of a research and demonstration project involving different types of the machines.

David Rabkin, the museum’s director for current science and technology, told NeighborMedia correspondent Mark Jaquith in April (www.cctvcambridge.org/node/16493) that because there is relatively little performance data on small-scale wind turbines, the information the project collects should help people thinking about installing them weigh their options.