With overwhelming support and enthusiasm from the public, the Town of Peterborough has built the largest solar array in the state (944 kW DC).  The project was funded by a $1.22 million PUC grant, with the remaining $1.4 million in total project costs being covered through a long-term power-purchase agreement (PPA) with Borrego Solar.  The array powers the Town's newly constructed wastewater treatment plant located off of Rt. 202 and helps to offset energy costs for other municipal buildings through a GNM agreement (Group Net Metering). 

The project is anticipated the save the town an estimated $250,000.00 to $500,000.00 over the next two decades.   This savings will be achieved through a long-term power-purchase agreement with Borrego Solar that enables the town to purchase power at a discounted rate (8 cents/kWh versus 14 cents/kWh) and new state rules regarding “virtual” net metering.  "Virtual” net metering allows for the benefits of energy captured at one site (in this case the Peterborough WWTF) to be shared among other buildings not directly attached to the energy capturing site.  This model enables a large-scale solar project to help offset the cost of purchasing energy elsewhere, as excess energy is captured and sold back to the larger energy grid.

  • Phase 1 of the project, filling of the former lagoon, was completed in the fall of 2014
  • Phase 2 construction of the solar array began in mid-November 2014
  • The solar array went online in the fall of 2015

The following files may be of assistance as you plan your own sustainable initiative: