By Paul Conyers
The Londonderry Energy Efficiency Task Force focused its Aug. 25 meeting around an ongoing plan to save money for the town by installing solar panels on several municipal buildings. The goal is to utilize solar power to defray part of the energy bill.
“Our subpanel was tasked with four criteria: to find the total annual energy usage for both the school building and the town buildings” explained Task Force member, Rick Darveau. “That’s what we did, we came up with a total annual energy kilowatt-hour consumption for the town buildings and the school buildings, and they are roughly just about equal, 1.5 million kilowatt hours per year.”
Determining the total kilowatt usage of both buildings will help Londonderry determine panel size requirements. Equally important was the combined, yearly electric bill for both buildings. This second calculation allows the Task Force to learn how many energy credits a solar array will generate. Calculations indicate a 70 percent generation rate might be possible under the current plan.
“If we’re looking at it combined, it’s 1.1 million dollars for the combined, total electric cost,” Darveau explained. “If you take 70 percent of that, that’s about 700 hundred thousand dollars, that’s rough figures that we’re getting back every year.”
The Task Force expects to get more accurate figures to finalize this estimate within the next few months. Some energy rebates earned through solar power will also be deducted from installation, operation, and maintenance costs.
Electricity can also act as a viable alternative to propane or natural gas when heating buildings during colder months. A heating gas like propane is also not deductible, unlike solar-generated energy, opening the door for additional savings to Londonderry by using electric heat pumps in some cases. No solid estimates are yet available on savings in this area.
Despite optimistic estimates, the Task Force brought up several possible issues. There were several public objections to the look of having solar panels going across all the buildings facing Mammoth Road. The police station was a problem owing to the large amount of glass in the building. Even ignoring the look of an array, not every building is in a position to support the extra weight of rooftop panels. The debate on where to build the array is ongoing.
With this in mind, other methods of saving energy were discussed with an eye to combining potential solar savings with better overall efficiency. One inexpensive option involves tinting windows in the police station to block heat from the sun, reducing cooling costs. A central control system can oversee climate control across several municipal buildings, leading to greater efficiency year-round. Several public buildings across town use unrelated, non-compatible climate control systems. The Task Force made plans to link up with the Londonderry School District, raising the possibility of tying efficiency ideas into the Facilities Master Plan.
The next Energy Task Force meeting is scheduled for Sept. 22 at 7 p.m. in the Moose Hill Council Chambers.