Pellets Warm County Seats
For more than 100 years, the red brick Oxford county courthouse in South Paris, Maine, warmed judges, commissioners, clerks, auditors and inmates with fossil fuel-derived heat. Those days are over. The courthouse, built in 1895, has just emerged from its third winter of utilizing locally produced wood pellets to heat its occupants and daily visitors.
Funded largely by an Energy Efficiency and Conservation Block Grant program that was a part of the stimulus package officially known as the 2009 American Reinvestment and Recovery Act, the new heating system has nearly halved the county’s annual heating expense. “The genesis of the project can be traced back to the stimulus package,” recalls Oxford county administrator Scott Cole. “We tried to get it going in 2010, but we realized we didn’t have the administrative capacity to handle it, so we punted one more year and we went after it with gusto in 2011, and succeeded.”
The project was broader and more involved than simply swapping out the existing heating oil boilers with new pellet boilers. The courthouse, a 17,000-square-foot, two-story structure that is situated over a basement was bleeding warm air through large, single-pane windows and a poorly insulated attic. This attracted the immediate attention and effort of the project engineer, Rick Grondin of Integrated Energy Systems. “We used some of the money to insulate the attic,” he says. “Instead of putting in one more boiler, I first looked to reduce the load and used dense-packed cellulose insulation in the attic.”
Further driving down the load was a move away from steam fed radiators to a forced hot water system. “It takes a lot less energy to make 140 degree water than it does to make 215 degree water,” Grondin notes.
After the completion of the attic insulation and window projects, the heat load requirements were determined, and Grondin went to work on satisfying the new heat load. Complicating the issue was the building’s limited space for its heating infrastructure. “We had a very small boiler room for all of this,” says Grondin. Through a competitive process, the county arrived at a system centered around the use of three pellet boilers of Austrian design. “The OkoFen boilers offered a solution that addressed all of the problems.”
OkoFen is an Austrian boiler manufactured, assembled and distributed in North America under a licensing agreement by Maine Energy Systems. Austrian manufacturers are global market leaders in pellet boiler design and manufacturing and their products are beginning to gain marketplace momentum in the U.S. and Canada.
Grondin and the county decided upon three separate boilers that would be connected to the same hot water delivery infrastructure. The boilers work together, communicate with one another and share the annual heating work load. Each boiler is capable of delivering 191,000 Btu per hour at full power. “The boilers are staged,” says Grondin. “When you have a very low load, one fires and then it modulates up to the next load requirement. If it can’t meet the load at full power, the second boiler fires and ramps up. If the load still isn’t met, the third boiler fires up.”
Largely, two boilers are able to generate the heat that the building thermostats call for. “Occasionally, the third boiler kicks on the coldest days,” adds Grondin.
Fuel Storage Challenges
The tight spaces in the boiler room also created fuel storage challenges for the project team. “Fuel storage is tough here,” says Cole. “The footprint of the building is not conducive to putting in a large silo, which would have been ideal.” Space around the building is at a premium, and snow removal already presents a challenge for Cole and his team, so a decision to move fuel storage inside of the building was made. “We really tried to find a place to put a 30-ton silo. In my opinion, that would have been preferable. We just couldn’t do it. Parking is tight. The last thing we needed was one more obstruction outside of the building, so we had to convert some space in the basement. I think we are a little undersized, but we had to have it that way,” says Cole.
In an average winter, the pellet boilers at the courthouse can be expected to consume somewhere between 65 and 70 tons of pellets. If the external silo Cole favored were feasible, around half of the annual usage could have been stored onsite, meaning that only one pellet delivery would have been necessary each heating season. Instead, two fabric storage bags were deployed into the boiler room with a total storage capacity of just over 16 tons. The county now takes fuel deliveries of between 8 and 10 tons of pellets seven or eight times in a given heating season. Pellets are delivered by Maine Energy Systems pellet delivery trucks, and pneumatically blown through hoses into the waiting storage bags in the courthouse.
Navigating the Learning Curve
All heating systems require some attention and technical acumen for the operators, and both Grondin and Cole recall a learning curve for the Oxford county maintenance staff. “The first year is more or less a learning experience for the facilities person, because it is something a little different,” says Grondin. “But really, the only thing they need to concern themselves with is making sure they have pellets to burn, ordering pellets and making sure that when the ash containers get full, they get emptied.”
Grondin is quick to point out the misconceptions surrounding the technology and its ease of use. “These are fully automated. When thinking about these types of solutions, people tend to think of wood stoves with all of their manual operations, manual adjustments during a fire and then the manual cleaning. This is the other end of the spectrum in the extreme. Maybe not as good as gas or oil in terms of low maintenance, but it’s pretty darn close,” he says.
For Cole, it was important to develop some technical know-how for the systems in-house. “The operation and maintenance is certainly trouble free. That said, it is good to have someone on the staff with a little training in troubleshooting the system. Someone has to really embrace the system and not just call on outside help right away,” he says, adding, “It’s not an enormous leap (relative to operating an oil-fired boiler), and it is certainly worth the savings.”
While Oxford County didn’t need to be convinced of the environmental benefits of a transition to pellet-derived heat, the budget-constrained county needed the project to deliver some savings, and the sooner, the better.
Before the transition to pellets the courthouse’s heating oil boilers consumed somewhere between 8500 and 10,000 gallons of heating oil each winter. With recent heating oil prices fluctuating between $3.50 and $4.00 per gallon, heating the building was costing the county between $30,000 and $40,000 a year.
Cole points to a comparison of 118 gallons of fuel oil and one ton of pellets, each delivering about the same amount of Btu. At a price of $3.50 per gallon, the heating oil Btu would cost $413. The county currently enjoys a three-year contract for pellets at $219 a ton, delivering a nearly 50 percent reduction in total heating cost. “We’ve cut our fuel costs in half,” notes Cole.
Stimulus Hastens Economic Benefit
Cole reports the project cost the county right around $300,000, with the Energy Efficiency and Conservation Block Grant contributing $235,000. The remaining funds were contributed by the county. “We could realize our savings much quicker because of the grant, because we didn’t have to amortize the cost of the capital,” says Cole.
With such a prominent building installing a pellet-fired heating solution and enjoying the economic benefits, it is no surprise that cities and schools in the county are taking notice. “Since the county installed its system, several of the town offices have gone to pellets as well, which is cool,” reports Cole. This momentum also has the net effect of getting more and more of the HVAC technicians in the area comfortable with these pellet technologies. “What we are noticing now, after having gone through three winters, is the familiarity with pellet boilers in the field of technicians has gone up,” Cole says. “It’s pretty cool. It’s happening. It’s definitely happening.”
Finally, Cole points to the growing pellet supply chain in the area and the positive economic impact of using local resources to heat local buildings. “It’s definitely a fuel that makes sense for this part of the world,” he adds.
Author: Tim Portz
Executive Editor, Biomass Magazine