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Supporters think the state’s forests have an important role to play in transitioning from fossil fuel heating sources.
As Vermont prepares to make a major push toward cleaner heat sources, some renewable energy advocates say wood from the state’s abundant forests should play an important role.
But other clean energy supporters say the state should instead focus on electrifying buildings, which they argue will lead to less pollution given the largely renewable electric grid.
The environmental calculus for wood heat is different from the more widely debated use of wood biomass like pellets to fuel electric generation plants. Burning wood for heat is far more efficient than using it to generate electricity, and modern boilers and stoves minimize pollution, making it a safe and affordable heat source, proponents say.
“When you go to the wood heating conversation, I always start with the understanding that there’s no perfect energy choice, so we need to compare energy choices with each other,” said Jared Duval, executive director of the Energy Action Network. The group is a coalition of members from business, advocacy, utilities and other realms who coordinate research and push for Vermont to meet its state renewable goal.
The state aims to obtain 90% of its energy from renewable sources by 2050. The network in March issued a progress report which showed, among other things, that Vermont’s thermal and transportation sectors are lagging behind the electric sector in reducing emissions. This is similar to a conclusion reached earlier this year by Vermont’s public utility commission.
Burning wood for electricity is only 20%-25% efficient, but it’s often 75%-80% efficient when used for heat, the report said, citing research from the Biomass Energy Resource Center. Other research showed that “using wood pellets harvested and produced in the Northeast immediately cuts greenhouse gas emissions by more than half compared to heating with fossil fuels,” the report said.
Vermont has a goal of getting 35% of its heating needs from wood by 2030. Homeowners and building managers have two primary options when considering wood heating systems: boilers and stoves. Boilers provide central heat, and stoves work more like a space heater. Either can use biomass like wood pellets.
Ideally, buildings would be retrofitted to use electric cold climate heat pumps, Duval said. With a mostly renewable electric grid in Vermont, this would be an emission-free energy source. But he added that since many buildings are larger and older, they’ll need some combustion source of heat, at least as a backup. Wood is far better than traditional fossil fuel heating, he said.
“And the benefit of wood is that, unlike fossil fuels, it contributes to the local economy,” Duval added. Vermont imports all of its fossil fuel and spends $2 billion a year doing so, he said. At a time like this, when states are trying to strengthen their economies, using local resources like forest wood will help Vermont build its own economy.
Sami Yassa, a senior scientist at the Natural Resources Defense Council, said that despite being more efficient than wood-fueled electricity, burning wood for heat still produces significant carbon emissions. It also produces air pollutants. So for schools considering switching to wood-burning boiler systems, “the question is whether these communities want their children, day after day, in an environment like that,” Yassa said.
Building electrification with heat pumps “is by far one of the cleanest and cheapest ways to go,” he said. He added that this is true for homes as well as larger buildings like schools and municipal facilities.
And while it may have been the case a few years ago that heat pumps were less efficient in cold climates, “it’s now well established that heat pumps operate in very cold climates like Vermont,” Yassa said.
“We need a whole variety of options,” said Maura Adams, program director of the Northern Forest Center. The center advocates for several forest-related issues in New England, including higher uptake of automated wood heating systems.
Like Duval at the Energy Action Network, Adams said heat pumps aren’t sufficient for all the state’s buildings. As for pollutants, she said, “there are very significant pollution controls that are installed” with wood heating systems.
Although heat pumps in this case would largely use clean energy, Vermont’s electric sector is smaller than transportation and heat, said Emma Hanson, the state’s wood energy coordinator. Hanson works in the state’s Department of Forests, Parks and Recreation, partnering with community groups to educate residents and other building owners on wood heat.
Because electricity makes up such a small portion of the state’s energy needs compared to heat and transportation, its capacity would be drained if the heat sector relied on it completely, Hanson said. “It’s impossible to take care of all of our thermal energy needs in Vermont with heat pumps.”
There’s also the issue of economics: Landowners need a market for their wood so they can pay taxes and keep their land from being developed. With dwindling opportunities to sell low-quality wood for purposes like paper, selling it for pellets helps fill the gap, Adams said.
Harris Roen, a licensed forester and founder of Long Meadow Resource Management, helps landowners assess and manage their forested land. He said he understands why people are concerned about pollution. “I hear what they’re saying,” he said, “but in my mind, keeping the forest [as] forest is the best thing that you can do,” especially since it serves as a valuable carbon sequester.
This, too, raises some debate: Yassa, at NRDC, argued that cutting down large, old trees dents forests’ ability to sequester carbon. Adams, though, said young trees sequester it faster, so if managed responsibly, new forest could complement the old.
Several supporters of wood heat emphasized the difference between that and using wood for electricity. The issues are often conflated, they said, but they don’t support using wood for electricity.
Adams noted the irony — that this issue has “turned into pitting environmentalists against environmentalists.” But she said it’s a balance: “There is no perfect solution for climate change. We have to heat with something.”
Correction: This article has been updated to correct the name of the organization whose research was cited in the Energy Action Network report. It is the Biomass Energy Resource Center.