New Hampshire, USA — What will be far and away New Hampshire’s largest solar energy system is beginning to take shape in the town of Peterborough. Its story could inspire other municipalities searching for answers to infrastructure and energy problems, and it could also help rewrite the state’s new policies on energy and net metering.
In 2000 the town of Peterborough, comfortably nestled against the Contoocook River against the Pack Monadnock mountain*, started planning for its new wastewater treatment plant and decommissioning the old one, both located just off Route 202 a couple of miles outside of town. Part of that decommissioning plan included desludging, dewatering and filling in three shallow sewage lagoons. Fast-forwarding to 2007, the town voted to reduce its carbon footprint by 10 percent by 2010, and pursued ways to do that from recycled paper to biomass pellet heating systems on multiple town buildings: the police station, town hall, and the new wastewater treatment plant.
Through all of those processes, the town kept thinking of what to do with those several acres of land at the old treatment plant — turning those lagoons into a wide, flat expanse with no trees or wetlands. And they hit upon an idea: build a solar array to help run the new plant’s pumps, aerators, and mechanical devices. “For solar siting, this is as close to perfect as you’re going to get,” recalled Rodney Bartlett, the town’s public works director. Conversations started in 2009 with Borrego Solar about what might work, and in 2012 they submitted a grant application to the New Hampshire Public Utilities Commission (PUC) for a decent-sized system (a few hundred kWs) owned by the town to power the new plant on-site, and also build new wires to help power the middle school across the street — and they were denied, partly because they wanted to fund it entirely with grant money. They also got wind of new legislation being worked out that would allow for “virtual” net metering — with that, they realized, they could restructure their plans to create a much bigger project to power not only the new treatment plant but also gain flexibility to apply excess generation to some of the town’s other buildings, structured through a PPA that would help pay most of the costs instead of relying so heavily on state funding.
In May 2013 the state’s PUC sent out its next request-for-proposals for renewable energy projects, for a pool of grants that had swelled to around $4 million — and received 35 applications totaling $21 million, ranging from biomass to small hydro upgrades and several commercial-scale solar project proposals. Among them was the reconfigured Peterborough project, which stood out due to its size (double the state’s current largest solar installation, currently at the Manchester airport), its example of land reuse, and how it might more broadly address the town’s economic pressures through sharing energy costs through the virtual net metering angle. The PUC also saw how the project would go a long way to helping the state achieve not only its renewable portfolio standards (25 percent by 2025), pointed out Jack Ruderman, director of the NH PUC’s sustainable energy division. Moreover, it could address a supply shortfall in renewable energy certificates (REC). “We’re trying to get as many [projects] in place as we can to add to the supply of RECs,” he said, “and this will do that in a significant way.”
Peterborough’s new wastewater treament plant. In the foreground, what looks like a field is actually
the sewage lagoon that will be drained and filled in, where the new solar array will be built.
Thus earlier this month the Peterborough solar project and its technical owner, Water Street Solar (a unit of Borrego Solar), were approved by the PUC for a $1.22 million state grant, to cover a big chunk of the estimated $2.6 million total system cost. The remaining $1.4 million will be paid through a long-term PPA, under which the town would pay 8 cents/kWh, compared with around 14 cents/kWh that the treatment plant and most town buildings currently pay for electricity, Bartlett said. Total savings over the 20-year contract would conservatively be $250,000, but might be twice that, Bartlett said. Having the old and new treatment plants next to each other also keeps costs down, not just avoiding transmission and distribution costs to send power to the grid, but no new onsite transmission is needed because the new state-of-the-art treatment plant can accommodate it. Construction is expected to begin by this fall and complete it next spring, well within the state grant’s two-year window. There are even plans to add a training room at the new plant to show off the array and the meters as they turn (and don’t turn) as power is pushed to the new plant and back to the grid. “It’s another touch of reality for what’s going on,” Bartlett said.
What to do with that excess power production is a key to this proposed project. New Hampshire’s net metering rules allowed PSNH to pay wholesale rate for a site’s electricity, or it could be banked and used as power when needed to offset the electricity bill. Those new rules for “virtual” net metering, approved last summer and enacted this month, spell out eligibility for what’s generated and used on the same meter with the same owner. The town, PUC, Borrego, and PSNH are now talking to figure out how this proposed project could be covered. “The reality of what we want to do is allowed in the statute, in our mind,” Bartlett said.
The PUC is looking ahead too, eager to know how the Peterborough project will influence the next grant process being prepared for this spring or early summer. “I wouldn’t be surprised” if other towns come up with their own proposals to replicate what Peterborough is doing, Ruderman said.
* (Disclaimer: for most of its life RenewableEnergyWorld.com called Peterborough home, and it still is for many of our staff. We’re biased.)
Lead image: Hand print on a solar background, via Shutterstock