Citing last year's turbine failure at the Granite Reliable Power wind park in Coos County, the park's owner is now asking the state for permission to widen the access roads in sensitive high-elevation areas to accommodate heavy equipment.
On March 12, Granite Reliable Power LLC, majority owned by Canadian-based Brookfield Renewable Power, filed a motion to amend its siting certificate issued in July 2009 by the New Hampshire Site Evaluation Committee (SEC).
A public hearing on the proposed amendment is scheduled for 6 p.m. April 7 at the Littleton Opera House in Littleton.
In mid-August 2013, one of the turbines on Mt. Kelsey required unscheduled maintenance because of a bearing failure, the company told SEC in its request for amendment.
That failure required the transport of crane components near the turbine that in turn required widening the access road.
"After further engineering and operational evaluation, it is now apparent that the Mt. Kelsey turbines will require periodic maintenance and that this maintenance necessitates a roadway wider than 12 feet," the company states.
The 33-turbine, 99-megawatt-capacity Granite Reliable wind park that went into operation in late 2011 stretches across 15 miles of ridge line in the unincorporated places of Dixville, Erving's Location, Millsfield and Odell and the town of Dummer.
The project was approved after a high-elevation mitigation settlement agreement between Granite Reliable Power and the Appalachian Mountain Club (AMC) and New Hampshire Department of Fish and Game.
That agreement currently states that only trees necessary for construction will be cut and after construction the roadway would be re-vegetated so the roadbed is limited to 12 feet in width.
The company, in its application, now seeks to expand the roadway width to 16 feet, stating "the maintenance requirements of the facility necessitate the repeated and periodic disturbance of the re-vegetated areas along the roadbed to accommodate heavy construction equipment."
On some corners, roadways will be wider than 16 feet to accommodate turning for large vehicles.
Brookfield representatives, when asked about the downed turbine in August, told The Caledonian-Record it was down because of scheduled maintenance.
A call placed Wednesday to Brookfield spokesman Zev Korman inquiring how many turbines need to be accessed on Mt. Kelsey and if the company foresees more turbine failures in the future was not immediately returned.
According to documents, the turbines are V90 models manufactured by Vestas.
In its application to SEC, Granite Reliable Power requests expedited consideration on the proposed amendment, by early May, stating the planting season is coming and the company would like to initiate a re-vegetation plan as soon as possible.
Th 2009 mitigation settlement agreement was entered into after concerns by AMC, Fish and Game and other interveners about impacts the project would have on sensitive high-elevation tree and wildlife species.
Fish and Game, in agreeing to the amendment, wants to add trees to the turbine pad areas and reduce the area of gravel surfaces, according to the application.
AMC has expressed concerns related to moisture retention for tree growth, routine roadside tree maintenance, and the use of a grass planting for soil stabilization in high areas, which could potentially attract predators.
The Granite Reliable amendment cites a post-construction pine marten study that states there is evidence of winter marten mortality by canine predators, such as fox and coyote, that are gaining access to high areas by way of roads.
That predation, according to the proposed amendment, could be increased because of high-elevation roadside grass seeding that creates habitat attractive to prey animals.
The company states the revised mitigation settlement agreement would accommodate all concerns.
Before construction of the wind park was complete, Brookfield representatives said 82 of the 99 megawatts were under 15-and 20-year contracts, with Green Mountain Power agreeing to purchase 32 percent of the output and Central Vermont Public Service 50.3 percent.