University of Maine at Farmington to build biomass heating plant

At the end of January, the University of Maine at Farmington received approval from the University of Maine System Board Of Trustees to move forward with plans to construct an $11 million biomass heat plant on campus. The biomass heating system will reduce the university’s carbon footprint by replacing up to 95 percent of its current fossil fuel use with wood chips.

On Feb. 9, project managers introduced the project at a board meeting to the planning board and Farmington residents. “We gathered questions to supply answers as we work towards approval, which we hope to receive on March 9,” said Jeff McKay, director of facilities management at UMF.

Once approved by the Farmington Planning Board, project planners expect to have final pricing for the project by March 15, with an anticipated groundbreaking in May. McKay said the hope is to be substantially completed with the project by the start of the school year in September. 

The proposed biomass plant will supply heat and domestic hot water to approximately 800,000 square-feet of space. “As it stands right now, the plan is that we’re going to have four injection-point boilers, which are relatively new, high-efficient boilers in some of our larger campus buildings,” McKay said. “Those will be used on the design days to help carry the load, and also the shoulder seasons before it’s cost effective to run the plant, and for the domestic hot water load for the summer.”

McKay adds that future plans include the installation of a second boiler once the boilers at the injection points become less efficient.

Besides the campus buildings, the biomass plant has the potential to serve a few buildings in the community. The Farmington Community Center has the potential to connect to the plant. According to McKay, the building is close enough to the biomass plant to run piping there for heat and hot water. It would cost an estimated $90,000 to make this connection, but the expected payback is around 7.5 years. Another community building that may be connected to the plant is the public library. “They have also asked us to give them an engineering price to hook them up, and that’s about a 12.5-year payback if that happens,” McKay said.

As for UMF, energy savings are estimated to recoup construction costs in 10 years. The biomass technology UMF is considering is a Messersmith boiler with 500 horsepower (hp), and a 40-year life expectancy. The entire campus requires an 800-hp boiler size, which will be met with the 500-hp boiler and the other injection-point boilers.

Although a feedstock provider for the boiler has not been formally selected, McKay said the university hopes to source its wood chips locally. The energy consultancy group Competitive Energy Services and engineering firm Trane Inc. provided data for the project, which showed that wood chips would cost $5.23 per MMBtu including handling, compared to $12.20 for wood pellets and $20.12 per MMBtu for heating oil as of Oct. 24.

The data also included that wood chips have an energy content of 9.46 MMBtu per ton with handling described as difficult, compared to wood pellets at 16.4 MMBtu per ton with moderate handling and heating oil at 5.76 MMBtu per barrel and easy to handle. According to UMF's design engineer Trane, "We have no data to suggest that the operational costs or particulate matter costs associated with a pellet system is appreciably less than that of a chip system."

Overall the campus will use mainly wood chips supplemented with some propane and heating oil. In total, the fuel mix with hot water system will generate 39,300 MMBtu, broken down into 90 percent of the load met with wood chips generating 35,400 MMBtu, 7 percent propane generating 2,700 MMBtu and 3 percent oil generating 1,200 MMBtu. This new system has the potential to reduce CO2 emissions by 8.15 million pounds.

The wood chips will be stored in a bin on the site, with the capacity to hold four truckloads of chips, or around 200 tons. The goal is to have the ability to store enough chips to run for four days at full capacity with no deliveries. During nonpeak times of winter, McKay estimates one truckload of wood chips delivered a week, and once the weather gets colder one every couple of days.

The engineering firm Trane estimates the steam-to hot-water conversion to yield a 20 percent fuel reduction from efficiency gains, and boiler upgrades to yield a further 10 percent fuel reduction. Competitive Energy Services calculated 2015 fuel savings. The estimated savings realized due to efficiency gains from a steam to hot water system change and price improvements over the heating oil price as of Oct. 24 is $830,800 for wood chips and $584,600 for wood pellets.

UMF plans to use the plant as a teaching tool once installed. “The plant has the potential of being incorporated into curriculum for programs such as sustainability, environmental and economic programs,” McKay said. “In addition, many of the local schools have shown interest in bringing students to see how the local resource is being used.”

The biomass plant aligns with the university’s emphasis on environmental stewardship. UMF has a Sustainable Campus Coalition whose role is to bring UMF staff, faculty and students together with the community of Farmington on topics related to environmental sustainability. “A number of our faculty, student and staff members have provided essential feedback and guidance on the development of the proposed biomass combined-heat-and-power system,” McKay said. “We are excited for the prospect of a new biomass plant and are encouraged by its contribution towards a more efficient and sustainable energy future for UMF.”