As proposed, homeowners could put up a maximum 80-foot-high tower, to hold a turbine with a maximum 10 kilowatt (kW) capacity. On properties less than 5 acres in size, one tower would be allowed. On parcels of 5 acres or more, up to three towers would be allowed.

Draft language proposes allowing towers of up to 120 feet tall in industrial and educational districts, with turbines of a maximum 50 kW capacity.

With that restriction, only several locations in town would qualify for the bigger turbines, such as MacQuinn’s gravel pit in Hulls Cove, The Jackson Laboratory, and the College of the Atlantic, board member David Bowden pointed out. He suggested that the ordinance be expanded to allow hotels and other commercial businesses to install the larger turbines, while also urging a cautious approach because many of those businesses abut residential districts.

The added height allowance for the bigger turbines was included because 50 kW turbines would need access to stronger winds, Mr. Hultgren said.

Under the draft ordinance, a tower would have to be set back from any structures and property lines a distance equal to the height of the tower. The setback could be reduced, however, if the tower design is certified by a licensed engineer.

The setback distance was set up to allow the installation of turbines on lots as small as 1 acre, Mr. Hultgren said.

Some board members said they would likely favor greater setbacks, largely because of potential noise generated by a turbine. Board member Kevin Cochary, for instance, suggested that an 80-foot tower should have to be set back from property lines by at least 120 feet, to help push the noise further from neighboring houses.

Mr. Hultgren said that such a provision would basically eliminate towers from one-acre lots, which Mr. Cochary said he didn’t have a problem with.

According to the American Wind Energy Association, modern residential wind turbines are no noisier than the average refrigerator.

As the draft ordinance is written, towers of less than 60 feet in height would be permitted by code enforcement officer approval, while taller towers would trigger planning board review.

Some on the board said that all towers more than 40 feet tall (the typical allowable height for structures in most zoning districts) should at least trigger a process whereby neighbors are notified and given the opportunity to comment.

The draft ordinance will be reviewed and commented upon by other town bodies, such as the conservation commission, and town department heads and staff over the coming weeks, Mr. Hultgren said. If the review process goes according to plan, the draft ordinance will go before the town council in time to be placed on the ballot for the June 2009 town meeting.