State’s biggest solar farm (although it’s not all that big, really) goes online Friday

PETERBOROUGH – The state’s biggest solar-power facility gets turned on Friday at the Peterborough Wastewater Treatment plant.
The facility falls just short of a megawatt, at 942 kilowatts, and is located on five acres of former wastewood lagoons. It has about 3,100 solar panels.

Megawatt-scale solar projects have become almost routine in Massachusetts and Vermont, both of which provide more financial support to solar power, but have yet to appear in New Hampshire.

The Peterborough solar farm will operate under what is known as a power purchase agreement, or PPA. The site was built and will be owned by Borrego Solar of Lowell, Mass., while Peterborough has agreed to buy all the plant’s output over the next 20 years. It starts at 8 cents per kilowatt hour, considerably below the market rate, and can increase up to 1 percent each year.

PPAs have become a standard instrument for funding large solar plants, and can now be bought and sold like other financial products such as mortgages. This has made financing large solar projects much easier.

Borrego Solar gets the federal investment tax credit for building and owning the site as well as a steady income stream over 20 years from the town’s payments.
The company received a $1.2 million grant from the state Public Utilities Commission as part of its renewable-energy grants, to cover part of the $2.6 million construction cost.

Also making the project possible is New Hampshire’s “virtual net metering” law, which allows group or large-scale solar projects to sell excess power back to the local utility, just as small-scale solar projects on homes have done for years.

The Peterborough solar farm is expected to generate about 800,000 to 1 million kilowatt-hours of power a year. The town’s new wastewater treatment plant will directly use about 700,000 kilowatt-hours of that total, while the rest will go out into the grid.

Friday’s ribbon cutting at 11 a.m. is scheduled to be attended by a number of state and local officials, and U.S. Sen. Jeanne Shaheen.

The treatment plant is at 110 Pheasant Road, just off state Route 202.