Cape Cod wind turbines put a spin on Island planning

Cape Cod wind turbines put a spin on Island planning

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Falmouth's wind turbine at the Wastewater Treatment Facility site — File photo by Janet Hefler

A recent tour of Cape Cod wind turbine facilities organized by the Martha’s Vineyard Commission (MVC) gave a group of Island planners an up-close look at the bladed behemoths at the Woods Hole Research Center, the Falmouth Wastewater Treatment Facility, and the Massachusetts Maritime Academy.

The group of about 20 included some MVC staff members and commissioners, Dukes County wind energy plan work group members, and town board and committee members with an interest in wind turbines.

The tour was a fact-finding mission for many in the group, who are involved in developing an Island-wide siting plan for wind turbines or town zoning bylaws and regulations.

MVC staff members set up the June 4 tour with the help of the Cape and Islands Self-Reliance Corporation (CISRC) and the Cape Cod Commission (CCC).

After an 8:15 am ferry crossing, the Island contingent boarded a yellow school bus for a short ride to the Woods Hole Research Center’s Gilman Ordway Campus in Falmouth, where they were joined by a group of about 10 from the CCC and CISRC.

Woods Hole Research Center (WHRC)

Turbine type: Northwind 100

Height: 156 feet

Rated maximum output: 100 kilowatts (kW)

Average annual production: about 26 kW over the past several months; anticipate an average annual output of about 160,000 kWh (turbine has not been on line for one year yet)

Project cost: $550,000; partially funded by a $225,000 grant from the Massachusetts Technology Collaborative Renewable Energy Trust.

The first stop on the tour reinforced a basic fact about wind turbines: if it’s not blowing, they’re not going.

Although morning fog gave way to dazzling sunshine and windless conditions, the lack of wind turbine action failed to deflate the tour group’s interest.

Research associate Joe Hackler got their hopes up with the news that the wind turbine “spools up” with gusts of wind as low as 10 to 11 miles per hour.

As a nonprofit organization, WHRC was not required to go through a special permitting process for the wind turbine, Mr. Hackler said. However, it does meet setback requirements and codes as required by zoning.

Mr. Hackler said WHRC held many public meetings and cultivated approval for the wind turbine from local residents for several years. “It got to the point that people were asking, when are you going to put that thing up?” he said.

The WHRC wind turbine was erected last August and began producing power in November. Asked about turbine noise, Mr. Hackler said it is difficult to gauge because the ambient noise level already is fairly high because of Woods Hole Road traffic.

One of the drawbacks about the wind turbine is that it sometimes develops a “resonance frequency” because of its tower design, Mr. Hackler said. Due to the height of the tower and the thickness of the metal, when the generator runs at a certain speed, a hum develops. He likened it to the sound of a glass that “sings” when someone rubs a finger around the rim.

Northern Power, the manufacturer, is trying to fix the problem by keeping the generator running at a lower speed. However, that means the turbine produces less power.

One of the wind turbine’s most noticeable visual impacts is shadow flicker from the rotating blades in the spring, winter, and fall.

“The flicker goes across the front of our building, and it’s like a strobe light that goes across the hall inside,” Mr. Hackler said. As a simple remedy, everyone with an office facing the wind turbine put up window shades.

“What’s startling is how far the shadow flicker reaches,” Mr. Hackler added. “It goes across Woods Hole Road to the other side.”

To mitigate the flicker, depending on the season and how many leaves are on the trees, WHRC turns the wind turbine off from 7 to 8:30 am every morning.

“We need to plant some more trees,” Mr. Hackler said.

Falmouth Wastewater Treatment Facility

Turbine type: Vestas V82

Height: 402 feet

Rated maximum output: 1,650 kilowatts

Average annual production: between 3- to 4-plus million kW hours (kWh)

Project cost: $4.3 million total; $3 million paid through Clean Energy Program/Community Wind Collaborative, grants, and renewable energy credit (REC) purchases; remainder funded by a town bond.

As far as wind turbine sites go, the Falmouth Wastewater Treatment Facility (FWTF) off Blacksmith Shop Road is considered a prime spot. Located on a 315-acre parcel of land zoned for industrial use, an imposing wind turbine sits on a hill with a panoramic view, with the ocean along one side.

The wind turbine currently is the tallest in the state, as proudly noted by Megan Amsler, executive director of CISRC and chairman of the Falmouth Energy Committee.

The energy committee began researching the wind turbine project in 2003. A meteorological tower went up in 2005. Ms. Amsler said a key component of any wind turbine project is educating constituents. Falmouth conducted many public hearings and project leaders attended seven different town meetings.

The turbine officially went on line on April 4 and underwent commissioning at the end of May. Since then, it has generated all of the electricity needed to run the Wastewater Treatment Facility, which is one of the biggest energy consumers among the town’s municipal buildings.

The wind turbine also is producing more than 5 percent of the town’s entire municipal energy load. While generating power, it creates a revenue stream to pay back the debt and offset electricity costs for the town, Ms. Amsler noted.

Falmouth also is erecting an identical turbine at a nearby technology park site. Ms. Amsler said the town is not considering any more wind turbine projects, however, because grant programs that made the first two financially viable are no longer available. Instead, she said, Falmouth would be putting its efforts towards energy efficiency and conservation, for which grant programs are now available.

Since the FWTF wind turbine began operating, the only complaints have been about noise from abutters within a quarter to a half-mile off Blacksmith Road.

“People describe it as sounding like a jet engine or also like a boot in the dryer,” Ms. Amsler said.

In response to the complaints, neighbors have been asked to keep sound logs, and an acoustical analysis is being done.

Mass Maritime Academy

Turbine type: Vestas V47

Height: 242 feet tall

Blade rotor diameter: 154 feet

Rated maximum output: 660 kW

Average annual production: one million kWh

Cost: $1.48 million; $500,000 funded by a grant from Mass Technology Collaborative

The last wind turbine visited finally provided a glimpse of spinning blades. The landmark machine on the MMA grounds, easily spotted from atop the Bourne Bridge, generates more than one-quarter of the campus’s electricity needs and reduces electricity costs by more than 27 percent.

MMA also sells renewable energy certificates at a price of $17 to $58 per megawatt generated annually, depending on the market, according to director of facilities Paul O’Keefe.

When MMA started its wind turbine project in 2005, Mr. O’Keefe said the school had to go through local conservation commissions and address issues such as property values, noise, and shadow flicker.

The turbine’s possible effect on birds was one of the major concerns. Although a desktop study concluded 2.15 to 4 birds might be killed a year, since the turbine went on line in June 2006, Mr. O’Keefe said only two dead birds have been found.

The MMA wind turbine also produces some shadow flicker from its blades, most often during late afternoon in winter, Mr. O’Keefe said. Since the turbine is close to a baseball field, the school shuts it down during games to keep it from affecting the players.

There have been no complaints about wind turbine noise from the neighbors or from students who live on campus, Mr. O’Keefe said.

However, recently, the turbine developed a soft, yet noticeable whistle sound caused by a small separation at the tip of one of the blades, which Mr. O’Keefe called to the tour group’s attention.

Mr. London suggested they walk to the end of the baseball field to see how far the whistling noise carried, which he determined was barely audible at about 450 feet away. The closest off-campus abutters are about 522 feet away.

Lessons learned

Most of the tour group’s questions focused on the visual impact of wind turbines, the effects of noise, vibration, and shadow flicker from blade rotation on abutters, and the difference in those effects based on proximity.

In a follow-up email after the tour, Mr. London offered a bulleted list he said he found useful for future Island wind energy planning.

“Turbines are impressive, even attractive, structures in the right location,” he wrote.

“The turbines generally seem to be operating well, except for issues with noise, and are producing as much or more energy than expected,” Mr. London added.

He also noted that two of the wind turbines are currently operating at limited capacity due to noise problems, even though they are set back from the nearest abutters at a greater distance than minimally required.

Mr. London said Islanders paid for their own ferry tickets, and the MVC paid for bus transportation from a Department of Housing and Community Development District Local Technical Assistance Grant.