For centuries, Mainers have relied on wood to heat their homes. And over the past few decades, many schools and universities have embraced wood heat, as well, in the form of biomass boilers, which have saved them money and reduced their reliance on fossil fuels.
But amid the current push toward solar, wind and heat pumps, questions are being raised about the role biomass should play in the state's energy future.
This story is part of our series "Climate Driven: A deep dive into Maine's response, one county at a time."
In the depths of a massive heating plant on the campus of the University of Maine in Farmington, Mechanical Manager Jason Beckler picks up a few freshly cut wood chips, still wet and aromatic.
"So it's that probably, these trees were cut, probably within the last 24 hours," he says.
Beckler says every few days or so during the winter, a giant tractor-trailer arrives on campus, where it dumps upwards of 30 tons of wood chips into a giant bin the size of a swimming pool, only narrower and deeper. The chips wind their way along a two-story conveyor belt, and are burned as fuel in a hot water boiler that heats 23 different buildings on the small, rural campus.
"So our boiler is 20 million BTUs. So it's equivalent to what we call a 500-horsepower boiler," Beckler says. "At the time, and I believe to still be the fact, that was the largest hot water appliance in the state of Maine."
The biomass heating system went live on the UMF campus about six years ago, replacing dozens of smaller, older boilers that required the college to purchase nearly 400,000 gallons of oil per heating season. The school says the new system is saving hundreds of thousands of dollars a year and has reduced oil purchased by close to 90%.
Former UMF Professor and Sustainability Coordinator Luke Kellett says that by requiring the wood chips to come from sustainably harvested trees within 50 miles of campus, the heating system is also investing in Franklin County's wood products industry.
"So it's become kind of a real proud, and iconic building. And I think most students and most staff and faculty are aware of it, they go walk by it, and they're proud of it," Kellett says. "It's taken UMF from just getting by on sustainability, to really making a big move in sustainability. Now we're thinking, what are the next moves?"
Over the last few decades, dozens of schools, colleges and businesses across western and northern Maine have switched from oil to wood chips or pellets as their primary heating source. But where does biomass fit in Maine's efforts to reduce future carbon emissions?
"So biomass does work for climate. But it depends on what you're using it for, and where it comes from. It also depends on how you consider time frame," says Andrea Colnes with the New England Forestry Foundation.
Colnes says that solely burning wood chips or pellets to generate electricity is generally not a climate-friendly option, as a lot of the energy is wasted, and burning still produces greenhouse gases.
But she noted that there is a benefit if wood if burned for heat, particularly if it comes from sustainably managed forests, and is material left over from the manufacturing process, such as the tops and limbs of trees.
"So there is a strong alignment between doing really good forestry, and the need for markets for that low-quality wood, that can help pay for that forest management over time. So they really do fit together," Colnes says.
A 2017 study found that while wood pellets aren't as climate-friendly as heat pumps, moving from heating oil to wood would still cut carbon emissions by more than half over 50 years.
Mark Berry, the forest program director with the Nature Conservancy in Maine, says with just a few decades to take monumental action to fight climate change, Maine will need to do whatever it can to reduce its carbon footprint, including adding more heat pumps and wood heat.
"We need to move rapidly to transition away from fossil fuels," Berry says. "And I think we need to use all the tools that we have, that can let us make improvements quickly."
Beckler at UMF says the biomass solution at the college makes sense in a community that's so intertwined with the forestry industry, even if it might not be as attractive for some schools or businesses in more urban settings.
"They might have said, 'Well, geez, I don't want that tractor-trailer truck full of wood chips coming past my house,'" Beckler says. "Where it's a common occurrence for us to see it every day. They pass through here on a daily basis, whether they're coming here or going someplace else."
The University of Maine in Orono is now also considering a biomass boiler as part of a range of energy options designed to move away from fossil fuels.
