New Hampshire’s Henniker Community School (HCS) has had a much-needed energy makeover. The work included a rather diverse group of individual projects, and it was managed by Energy Efficiency Investments (EEI) of Merrimack, New Hampshire, which did much of the work itself. One of the important projects was a rooftop solar array, installed by 603 Solar of Exeter, New Hampshire.
Keith McBrien, Business Development Specialist at EEI called the company an “energy performance contractor.” The goal of the company is to reduce the energy use and carbon footprint of a business or organization without increasing its costs. He said, “We worked to help with the school to replace aging equipment with highly energy efficient and renewable energy options to help reduce the energy usage costs of the school.”
The work done at HCS was not a simple upgrade. Among the things that EEI did was to replace three roofs. One was a rubber membrane roof that was 25 years old and was replaced by a new rubber membrane. The second was an asphalt roof that was at the end of its life, and the third was a slate roof that was installed in the 1930s. The latter two roofs were replaced with asphalt shingles. In addition, the insulation for the building was upgraded.
EEI replaced the HVAC equipment with variable refrigerant flow heat pumps from Daikin. At the same time, the oil-burning heating system for the school was replaced with one that burns propane. McBrien explained that there were areas in the school, particularly the cafeteria and gymnasium, where propane was considered appropriate.
The fluorescent lighting at HCS was replaced by new LED lights from Phillips. In a school, this is an important upgrade.
McBrien said that EEI works to reduce energy costs of operating the building enough to cover the costs of upgrading the existing system. In the case of HCS, the work included some upgrades that were not addressed in the system being replaced, but which were considered important. All classrooms are now heated with heat pumps, making it possible to add improvements in air quality greatly with increased circulation. This is especially important in an age of Covid-19.
One important addition to HCS was installation of a solar array. The decision to install the array dates back to May 2020, when voters in the town of Henniker, approved installation of a roof-mounted solar array on school buildings. The cost was expected to be slightly less than $295,000. The solar array was to be just part of a needed upgrade for energy efficiency.
The array was designed, engineered and is now monitored by 603 Solar while the physical installation, inspection and commissioning was performed by Adams Energy of Canterbury, NH.
The array at HCS is impressive. It is expected that the solar array will generate about 115,000 kilowatt-hours (kWh) of electricity each year, equivalent to reducing greenhouse gas emissions of 81.5 metric tons. According to Keith McBrien, this is sufficient to offset about half of the school’s electricity use. It has a total of 250 Hanwha Q.Peak Duo 400-watt solar modules. These are tied to two 43.2 kWh Solar Edge three-phase string inverters. The array is set up on a ballast block racking system from Ecolibrium Solar on four flat roof areas.
Zach Haithcock of 603 Solar said, “We love working with schools and municipalities to realize their renewable energy goals. Not only are they really fun projects to work on, but they also raise awareness in the area regarding renewable energy. When you see your local school or town hall install solar, it really gets people’s attention and motivates them to look into it for themselves!”
Haithcock said 603 Solar and EEI had worked together before when the Newmarket, NH fire department had similar work done using similar equipment.