NH Guard strives for net-zero energy use at training site
Photovoltaic panels are affixed to buildings at the New Hampshire National Guard Training Site in Center Strafford. The panels produce enough power to run the site's operation center, known as Cooper House. The NHNG aims to achieve energy resiliency at the site. (Photo Credit: Staff Sgt. Charles Johnston) VIEW ORIGINAL

CENTER STRAFFORD, N.H. – October is National Energy Awareness Month.

Each fall, the Army highlights reducing energy consumption at its facilities at home and in theater, while increasing efficiency and reducing costs.

The New Hampshire National Guard makes this a point of emphasis year-round.

“A while ago, the Army started moving towards renewable energy and energy reduction in the military,” said Maj. Logan Kenney, design and construction branch chief. “So we focused on Center Strafford, our training site, trying to bring down the water and energy usage to net zero.”

Nestled amid farmland, rolling hills and colonial-era houses, the Center Strafford site was once home to an academy established in the early 1900s. After the school closed, the Guard acquired the sprawling 100-acre campus in the ‘80s.

The property has been renovated and improved over the years, but improving energy efficiency has only recently become a priority. The goal: net-zero consumption – using only energy equal to or less than the amount of renewable energy created on-site.

“It’s not really achievable to be net-zero in the military because you’re always using energy from somewhere,” Kenney said. “We have training needs. We can’t actually have a building not function and meet our requirements for computers, digital trainers, etc., so we focused on near net-zero. We’re trying to do it for the campus by doing that with renewable energies and focusing on solar panels, primarily.”

The first step was adding photovoltaic (PV) arrays of solar panels to the rooftops of five structures. A massive ground-mounted system was erected near the outdoor shooting range. Even streetlamps were affixed with small PV panels.

Energy credits are accrued through a local power company for every kilowatt generated by the solar arrays. At a cost of about $3 million, the return on investment is expected to take about 21 years. But the option exists to power directly from the panels, if necessary.

“There is enough [energy] to offset at least one of the buildings in operation,” Kenney said.

That building is the site’s maintenance and operations center, a 3,000-square-foot structure known as Cooper House.

“Cooper House was the final phase for the solar that’s currently installed out there,” said Warrant Officer Ben Stevens, construction project manager. “We wanted to bundle it all together and put it into a building where it was easily measurable against that near net-zero kind of concept. Anything that’s produced in those solar panels on the rest of the site, in theory, offsets the power requirement and consumption of just Cooper House.”

“It was basically a full renovation of the building to make it more superiorly insulated,” said Ken Coombs, state architect.

The 2018 renovation was deemed an essential part of the plan, which stripped the old house right down to the studs.

“The near net-zero doesn’t just come from the production of the solar balance production consumption of that building,” Stevens said. “It’s a combination. It’s an equation of everything we’ve done in that building. The walls were spray-foamed. There’s a full-building envelope. There is no thermal break in that building or thermal conductivity from the inside to the outside, to include underneath the floors in many of the renovated spaces. And that makes it a tighter building.”

The heating, ventilation and air conditioning system was also replaced with electric heat pumps. “There’s no fossil fuel consumption in that building,” Stevens said. “We disconnected all the propane tanks.”

The next phase of the plan entails installating a 50,000-gallon water tank and an on-site treatment system, Kenney said. No outside resources will be needed to operate it.

Wind power may also be employed in the not-too-distant future. But for now, preliminary studies suggest conventional wind turbines won’t maximize airflows distorted by nearby Parker Mountain.

“The wind changes direction too often,” Kenney said. “Because it keeps moving degrees and speed, we could get wind, but we would not harvest enough energy to warrant the cost of a project.”

In the meantime, the site’s PV panel production versus the exact energy consumption of Cooper House is being analyzed and evaluated with new, high-tech software. And while near net-zero is the still the target, the future holds loftier goals.

“Theoretically to run completely off the grid, that’s sort of what we were looking towards,” Kenney said.