GREENWOOD — Representatives of the Calpine Wind Corp. are scheduled to make a presentation to selectmen Tuesday, Feb. 6.

It will begin at 5:30 p.m. at the Town Office or the adjacent Legion Hall, depending on attendance.

Calpine is studying the viability of a wind power project in the area of Long, Tibbetts and Elwell mountains, near Twitchell Pond, on land owned by the Weyerhaeuser Co., one of the world’s largest private owners of timberlands. 

The meeting is expected to include information being gathered by a meteorological tower on Long Mountain and potential tax revenue if Calpine goes forward with a project, Town Manager Kim Sparks said.

The town Budget Committee is also expected to attend the meeting.

Prompted by the potential Calpine development, Greenwood’s Ordinance Review Committee is considering updates for the town’s commercial wind ordinance. The recent development of new technology, particularly taller towers, makes more locations in Greenwood viable for potential wind projects. Changes to the ordinance would have to be approved by town voters.

The town ordinance limits decibel levels from routine operation of wind turbines to 55 in the daytime and 42 at night at non-participating property lines, the same as state guidelines. Setbacks from property lines are a minimum of 150 percent of the height of the towers. There are no height limits specified.

The Ordinance Review Committee has recommended decibel limits of 35 maximum for daytime and 25 maximum at night. The panel also voted to limit tower heights to 250 feet and establish setbacks of 1 mile per 100 feet of tower height.

At its meeting last week the committee discussed “infrasound,” or low-frequency sound emitted by wind turbines. About three dozen people attended the meeting.

The committee voted to recommend a limit of no more than 6 decibals higher than background infrasound, based on measurements taken from adjacent properties. The figure was suggested by acoustical consultant Michael Bahtiarian of Acentech, of Cambridge, Mass.

Committee members noted it would be important to require a pre-construction sound analysis for any wind project, to get the correct baseline measurements for comparison before and after.

Chairman Larry Merlino said Bahtiarian noted that the setbacks recommended by the committee could make infrasound non-detectable from those distances anyway. In comments after the meeting, Betsey Foster, a former member of the committed, cautioned that non-detectable noise was based on towers 360 feet tall, and the 600-foot towers under consideration by Calpine could project farther. She also said “non-detectable” only reflects the limit of the equipment used to measure infrasound. “Because it’s non-detectable doesn’t mean it’s not there,” she said.

Ed Rosenberg urged the committee to include a requirement that a wind company provide funds to the town for measuring background infrasound when the developer first comes to the town for a permit for a meteorological tower.

Committee members planned to individually study the town’s current Site Plan Review Ordinance section on wind power pertaining to scenic resources, to see if new language might be considered at the next meeting.

The committee will meet at 5:30 p.m. Thursday, Feb. 1, at the Town Office.