Andover Town Meeting in March 2017 approved air-based heat pumps and solar panels for the Town Offices building to save energy and lower costs for the Town and improve the building’s working environment. The heat pumps were installed in April 2017 and the solar system began generating at the end of October 2017.
The solar system was acquired through a Power Purchase Agreement (PPA) with ReVision Energy, the system installer. Under the PPA, the Town pays ReVision for power generated by the solar panels for six years at a below-market rate, and then purchases the system at a discount. The Town is therefore slated to purchase the system in October 2023.
Here are key results for 2021 (specifically, the 12 months from November 2020 through October 2021 – we previously set the reporting cycle this way to allow reporting in time for publication of the annual Town Report):
As in the prior two years, in 2021 the solar panels produced more power than expected (23,004 kWhs produced compared to 21,494 kWhs expected). This performance exceeds the output specified in the PPA by 7%. This now multi-year trend of outperforming specification shows that the Town received good value under the agreement with ReVision, and is an indicator that the system will produce reliably for years into the future. The system’s monitor also shows that each of the individual panels is producing at consistent levels.
The solar system aligns with the needs of the building (in 2021 the building consumed a total of 19,693 kWhs, a bit less than it produced).
In 2021 the energy upgrades and solar panels together saved the Town $784 in electricity and oil costs. Once the Town owns the solar system, the annual savings will jump dramatically since it will pay nothing for all the power the system generates.
The annual electricity savings so far from the solar by itself has varied from $100 to over $500. At today’s electricity rates, when the Town owns the system, that savings jumps to $2,500, so for 2021, if the Town had already owned the system the total savings would have been over $3,200. As fuel and utility rates continue to rise, these annual savings will grow.
The Town would be able to save even more by taking steps to concentrate heating and cooling during the hours the solar system is producing and thereby reducing the amount it exports to NHEC for credit, and also by installing additional heat pump capacity to shift more heat to electric instead of oil and further minimize export back to NHEC of solar-generated power in the heating months. There is ample solar generation to support an additional heat pump.
Since their installation in 2017, neither the heat pumps nor the solar components have required any maintenance.
Since going live in late October 2017, the Town Offices solar system has saved over 143,000 pounds of CO2 from entering the atmosphere, the equivalent of over 1,000 newly planted trees grown for 10 years. The Town Offices energy upgrade demonstrates that it is possible both to save money and to help the environment.
The Town is scheduled to purchase the solar panel system in October 2023. The purchase price is $17,724, a very substantial discount from the installed value of the system of $59,081. It is critical that the Town conclude the purchase at that time, first in order to maximize the Town’s savings over the lifetime of the system, and second because under the PPA the rate paid for power generated by the solar panels will rise if the Town does not timely exercise its purchase. With the annual savings upon ownership, added to the savings the system has provided to date, the system purchase is expected to pay for itself in under seven years.
The March 2017 Town Meeting approval provided that the Town would set aside 1/6th of the $17,724 purchase price (or $2,954) every year for six years from the Unassigned Fund Balance into a dedicated Solar Energy Capital Reserve Fund to fund the purchase. Because the reserve funds come from the Unassigned Fund Balance there is no tax impact, and this accrual approach minimizes the financial impact to the Town year by year.
Payments that were approved and set aside in Town Meetings in March 2017 through March 2020 have now funded 5/6 the system’s purchase price. Assuming Town Meeting approval of this year’s final $2,954 installment, the Town will be in position to complete the purchase in October 2023.