Operation Biomass Heat

Wood heat is keeping the Vermont Army National Guard warm during the winter.
By Anna Simet | October 22, 2015

Since it opened in 2003, the Vermont Army National Guard's Readiness & Regional Technology Center has been referred to as the armory of the future, housing numerous different branches of the U.S. military. The 87,000-square foot, cutting-edge training and technology center serves as headquarters to the 86th Infantry Brigade Support Battalion (Mountain), an information operations schoolhouse for both the U.S. Army and U.S. Air Force, and a premier training and simulation center for the Northeast U.S.

Located at the oldest private military school in the country, Norwich University in Northfield, Vermont, the facility has continued its trend of innovation with the recent installation of four P4 Fröling wood pellet boilers, which was complete in the spring. “The decision to install the pellet system was driven by the need to increase our renewable energy sources, but it needed to have an acceptable return on investment, or savings to investment ratio,” says VTARNG Energy Manager William Moore. “Payback was calculated with wood pellet pricing at $12.24 per MMBtu, or $208 per ton,” he says. At that time, the boilers presented a higher return on investment than solar PV panel electricity generation, solar domestic hot water heating and solar building heat, adds Major Jere Berg, project manager.

But fast forward to October 2015, and bulk-delivered pellets are being sold at an average of $245 and $275 per ton, considerably higher than projected. While not ideal, as commissioning of the system looms, wood pellet prices are much more stable than those of oil, and pellet heat remains an effective, simple means of meeting military renewable mandates and achieve energy self-sufficiency.
The system was installed by Sunwood Biomass, a Vermont–based firm that has completed over 130 projects across the state. Owner David Frank highlights the unique storage system at the RRTC, which was devised after determining outdoor space wasn’t sufficient. Pellets are delivered on site and pneumatically pumped into two 25-ton storage silos located in the boiler room. “Pellet silos are vented to the outside to minimize any carbon monoxide (CO) concerns, and are activated with a CO sensor,” Frank adds. 

The automatic, low-maintenance system, Moore says, is clean and simple to operate. It is estimated to offset roughly 19,000 gallons of fuel oil annually, providing an annual savings of around $30,000.
While the pellet boiler system is yet to be commissioned, the VTARNG is no stranger to wood heat. A ChipTek wood chip gasifier was installed at the Combined Support Maintenance Shop at Camp Johnson in Colchester, Vermont, in 2000, and is still heating the facility today. Unlike the wood pellet boilers at RRTC, the Chiptek system was part of the facility’s original design. “The main driver for installing the wood chip system was economics,” says Moore. “The cost of wood chips then was about $39 per ton, and natural gas at CSMS was 89 cents per CCF.

Other than the gasifier itself, the system is fairly simple, says Peter Tousley, also an energy manager, and parts are “pretty much off the shelf.”

At Camp Johnson, wood chips are stored in a circular storage barn and delivered to the auger trough bin via a front-end loader. The system does requires quite a bit more oversight than the pellet system will, which includes refilling the chip hopper, cleaning out the ash, and keeping the augers operating.  However, Moore notes that the wood chip unit is nearly 15 years old, and says technology has likely significantly evolved since then.

Wood chips for the system are supplied via a state contract. Moore says the facility has been using an average of about 230 tons per year for the past few years, and local suppliers have included Vermont companies such as Claire Lathrop Band Mill and LimLaw pulp.

Finding a supply of wood chips hasn’t been a problem, according to Tousley, but increasing fuel costs have been a challenge. “Most recently, when the chip supply contract went out to bid, our supplier didn’t bid,” Moore adds.

Up until last year, the wood chip boiler operated from roughly November to March and was approximately one-half the cost of natural gas, Tousley says, although since it was installed 15 years ago, wood chip prices have doubled and natural gas has been on the downslide. However, as is the case with oil, natural gas prices are volatile and, eventually, will rise again.

Despite temporary challenges with increasing fuel costs, utilization of wood chip fuel, as well as pellets and cordwood—a few of its firing ranges in Jericho, Vermont, are heated with woodstoves—keeps the Vermont Army National Guard on par with mandates

“It [biomass] helps the VTARNG meet renewable energy goals as outlined in Executive Orders to the Department of Defense,” says Tousley.

Authors: Anna Simet
Managing Editor, Biomass Magazine
[email protected]