By Gregory Barros
HARVARD — The Wind Energy Conversion Systems Committee has sent its recommendations for residential wind-power generation to the Planning Board.
The group’s recommendations address the concerns and issues the community expressed at the group’s informational presentation held earlier this month, said Chairman Ruth Silman.
“Even though we’re in the preliminary stage of our review of the technology, we’re seeing mostly support from the community,” she said.
The Planning Board chartered the committee in October to investigate the feasibility of amending the town’s zoning bylaws to allow for residential wind-energy-conversion systems.
The committee’s mandate includes researching available technology, examining bylaws in other towns, examining Harvard’s bylaws, analyzing the benefits of wind energy structures, advising on the potential for state legislation requiring the permitting for such devices and proposing a suitable process for obtaining a permit should the town allow the use of wind energy.
Last month, the Zoning Board of Appeals (ZBA) permitted a wind-power generator at the Nigzus farm on Madigan Lane for agricultural use. The ZBA’s override of the building inspector’s permit denial applied to Steve Nigzus’ application only.
Several concerns rose from the December presentation, said Silman, which the group intends to investigate further.
The systems, according to the committee, make about as much sound as the wind and could be just as noticeable.
Also affecting Harvard’s environment would be the view of the systems. But the committee maintains that the impact would be slight due to structures’ small sizes and thin rotors.
However, the systems would likely be noticeable because, for optimum results, they’d be place up high to take advantage of the wind speed and power increase that come with height. Similarly, residents would optimize their systems by placing them clear of obstructions.
The impact of the systems on the town’s avian inhabitants, birds and bats, would be minimal, said committee members. There have been bird and bat issues with large wind farms, according to the group. But their conclusion is that residential wind-power generators still account for a relatively small percentage of total bird deaths compared to communication towers, pesticides, vehicles, high-tension lines, buildings and house pets.
Safety-wise, the committee reported that manufacturers design their towers to withstand high winds and discourage and restrict climbing.
Manufacturers also build their systems’ turbines with electronic over-speed, stall and disconnect controls for safer operations. The disconnect controls would detach the power generator from the power grid in case there’s a power outage.
The final concern for the committee is the wind-power system management policies, procedures and methods, especially at the end of the life of a wind conversion device.
“People are particularly concerned that we speak to provisions for handling systems that have come to the ends of their useful lives,” said Silman.
The wind-power-generating devices are typically small turbines with three to four moving parts at the top of a tower structure to “catch” the wind. The low number of movable parts means low maintenance requirements.
The committee’s research indicates that the wind speed range in Harvard — averaging about 11 miles per hour — is acceptable for harvesting.
Wind velocity is one of the two factors affecting the amount of power the device could generate. The greater the wind speed, the more power the system could generate.
The turbine rotor is the other factor. The longer the length of the rotor’s blades, the greater the area the rotor sweeps, and the greater the power the system creates.
The devices most suitable for the town would range from 400 watts to 60 kilowatts, said committee member John Sweeney. Installation costs would range from $5,000 to $60,000 based on turbine and tower sizes.
The electrical-power-generating industry has integrated wind energy into the electric grid, he said, which saves the cost of energy storage and conversion.
“Net metering through utilities means you would pay for your net use of energy,” he said. “That’s your kilowatt hours used minus your kilowatt hours generated.”
Residential wind-power use could save residents money, reduce the amount of carbon dioxide released into our environment, and reduce the amount of oil and coal consumed for energy production, he said, lessening dependence on other countries for these raw materials.