AMHERST — Roofs, parking lots and grounds at the Amherst Regional middle and high schools are being identified in a report as the best town- and school-owned sites in Amherst for solar arrays and battery storage.
Whether officials will pursue such renewable energy projects at the identified locations, though, could depend on getting more information, including whether the roof at the middle school can support installation of photovoltaics without a significant investment.
The conclusions about the best municipal properties for renewable energy are included in the “Amherst Solar and Energy Storage Assessment” prepared by the Cadmus Group of Waltham using an earmark from state Rep. Mindy Domb, D-Amherst.
“This is a bird’s-eye view of potential for generating electricity through photovoltaics and also using battery storage or energy storage systems to store power and use at the schools, or in the grid,” Facilities Supervisor Rupert Roy-Clark told the Regional School Committee at its Oct. 25 meeting.
The report notes that models are based on 20 years of operation, and it provides an analysis of estimated lifetime net present value savings, or NPV savings, over that timeframe compared to what is termed “business as usual.”
“Lifetime NPV savings are largely driven by the site solar potential and required battery size to meet demand during an outage,” the report’s authors write. “Sites with higher solar potential (e.g., all school sites) have greater lifetime NPV savings, while sites with limited solar potential and large battery size requirement — especially the police station — have lifetime negative NPV relative to business as usual.”
The lifetime net present value savings are $2.88 million for the middle school and $960,448 for the high school, when batteries that would be included are sized to supply power for 24-hour outages.
Other sites examined included the Bangs Community Center, the police station, the North fire station, Crocker Farm Elementary School, the Spring Street and Pray Street parking lots, the Boltwood parking garage and the Cherry Hill golf course.
Those 10 sites currently use an estimated 3.6 million kilowatt hours of electricity each year, costing the town more than $620,000. They have the potential to host up to 3,826 kilowatts of direct current of new solar PV capacity, enough to generate an estimated 4.6 million kilowatt hours of clean electricity annually, and offset 128% of on-site electricity demand at those facilities.
The report notes that the maximum NPV savings of $4.1 million could be achieved under circumstances where all batteries are sized for a 24-hour outage, the battery at the police station would be sized to meet half of that building’s on-site load during an outage, and strategically felling some trees at the Bangs and Crocker Farm to increase the solar potential.
Roy-Clark notes that the potential of $3 million in savings at the middle school would be offset if significant investment has to be made in the roof. A December 2017 report showed the roof was in need of an estimated $2.47 million in replacements and repairs, based on an independent engineering consulting firm. At the time, the schools applied for funding from the Massachusetts School Building Authority.
Before pursuing any plans, Roy-Clark said Cadmus may need to better define the critical load on each building and what functions short- and long-term power are needed for, and re-engage with the town and schools to get new data for new LED lights and air conditioning, as well as the expanding fleet of electric vehicles.