What Are The Pros And Cons Of Heating With Wood?
Burned out on election news? We've got you. Revisit our 2019 episode about the fuel that warms you twice.
Editor's note: As always, we recommend listening to the audio! We released this episode on January 11, 2019. To hear the original audio, scroll to the bottom of the page.
In the winter, Coco and Emmet Moseley keep their farmhouse cozy and warm with an antique wood stove — and Coco is wondering about the benefits and drawbacks of their heat source.
The Moseleys live at the end of a dead-end road in Lincoln, surrounded by the Green Mountain National Forest. They have a horse, a rooster, a 5-week-old baby, and 135 acres of woods. They spend the year managing and logging their property, and in the winter, they burn the fruits of their labor: six cords.
Coco brought her curiosity to Brave Little State, VPR’s people-powered journalism project. Every month we answer a question about Vermont that’s been submitted and voted on by you, our audience. Coco’s question is our latest winner:
"What are the environmental and economic benefits of wood heat in Vermont? And then what are the costs to that?"
Coco continues: “I assume that there’s of course some positives to not relying on fossil fuels. But what else is part of the story here?”
It’s a brave question for someone so enamored of her wood stove. And Coco isn’t alone: According to the 2010 U.S. Census, Vermont has the highest percentage of primary residences that heat with wood.
And for wood heat aficionados, many benefits of the heat source are self-evident: The toastiness of the fire, the glow of the flame. The romance of stacking wood, and the good old Yankee pleasure of working with a fuel that heats you twice. (Or three times, or however many times you have to schlep it around.) Plus, if you have woods on your property? You’ve got free heat.
But there are cons, too. We’ll get to those.
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Economic & environmental benefits
As far as the benefits of wood heat go, you couldn’t find a more enthusiastic proponent than Emma Hanson.
“We can feel great about heating with wood,” says Emma, who works as the wood energy coordinator at the Vermont Department of Forests, Parks and Recreation.
“Wood fuel is great, because in Vermont — where we're blessed with 78 percent forested landscape — it is our local, renewable, sustainable resource,” she adds.
Emma can tick off sparkly statistics about heating with wood like it’s her job — because it is.
“My favorite thing to point out when I'm talking about wood heat in Vermont is that when Vermonters heat with fossil fuel, 78 cents of every dollar leaves the state,” she says. “Whereas when we heat with locally sourced wood, the inverse of that is true. So all that money stays right here in our communities, creating jobs for our neighbors, retaining local wealth. It's all those fuzzy, feel-good things you get when you buy produce from the farmers market, same idea.”
Emma has stickers on her laptop that say “Local Wood, Local Good” and “Buy Local, Burn Local.” She says in addition to keeping money in the Vermont economy, heating with wood is almost always cheaper. While the price of fossil fuels go up and down, “you see wood fuels just sort of happily chugging along with the price of inflation, really predictably and really affordably,” she says.
So those are two big economic benefits. As for the environmental benefits, obviously, when you burn wood you’re not burning fossil fuel.
Or, as Emma puts it: “Wood heat is a lot more sustainable than waiting for more dinosaurs to decompose and create more oil for us.”
And it’s easy to think of wood heat as pretty green, right? Trees, hello? Unfortunately it does have some environmental drawbacks, which we’ll get to later on.
But as far as the state of Vermont is concerned, wood heat is one of the keys to meeting our goals around renewable energy. The state’s Comprehensive Energy Plan has an overall goal of reaching 90 percent renewable energy by 2050; within that is a goal to obtain 35 percent of our thermal energy needs from wood heat by 2030. (According to Emma Hanson, we’re currently at about 21 percent.)
This brings us to another environmental benefit that Emma talked about.
“Pretty much every presentation I give, I point out that I work for the Department of Forest Parks and Recreation,” Emma says. “And the reason the Department of Forest Parks and Recreation has a vested interest in burning more trees — which can kind of catch people by surprise. ‘Why would you be interested in that?’ And it's because of forest health.”
It might seem counter-intuitive, but Emma says that the best way to take care of Vermont’s forests is to log them. Sustainably. Because if you don’t — if there’s not a strong logging industry — the forests might not always be forests.
“Vermonters love our landscape and love it looking the way it looks,” Emma says. “And most of the forest here is privately owned, and so in order for that to work, those landowners need to be able to make that small amount of income, to have those healthy markets for both the high- and low-grade wood from their land.”
High- and low-grade wood. These are important categories in forestry. High-grade wood is what carpenters use for two-by-fours, flooring and the like. Low-grade is is for cordwood or wood chips.
“Or, in our area, traditionally [low-grade wood] would go to the paper mills, and the paper mills have really struggled in recent years, which has been really hard,” Emma says.
That’s because without a demand for both types of wood — high-grade and low-grade — people who own forest land can’t get as much value out of it. Which means they’re more likely to develop it.
“And it might just be 5 acres here and 5 acres there. But that's when you start to see the smaller … parcels,” Emma says, referencing forest fragmentation. “And according to a Harvard study that came out almost two years ago now, Vermont is losing 15,00 acres of forest a year to rural and suburban development. And that's what we're concerned about.”
To get a better sense of what sustainable forestry looks like, we head to a logging job.
On a snowy morning in the Mount Mansfield State Forest, in a valley behind Smugglers’ Notch ski area, we met up with Jordan Pratt and his father Don, a veteran logger. Jordan’s business, Pratt’s Forest Management, has a contract with the state to log here.
Unfortunately the men aren’t logging on the day of our visit, because there’s rain in the forecast, and their skid tracks aren’t frozen in. But Jordan explains the basic concept of selective timber management:
“If you go into a section like this, and you’ve got a lot of old-growth timber, take some of it out, leave some of it to grow. Take some of your younger generation that’s not growing into good stuff, use that mainly for your firewood or chipwood, and try and use every bit of it you can.”
Paul Frederick, who also joined the conversation, compares the practice to weeding a garden. Paul works with Emma Hanson, as the state’s wood utilization & wood energy program leader.
“You want to harvest some of your vegetables, but you want to make sure that you’re pulling the weeds as well,” Paul says. “[So] that low-grade material is sort of the weeds, and there’s only just so much sunlight to go around in a forested stand, and letting the better quality wood have that sunlight helps it grow a little faster and a little better.
The state sets conditions that loggers have to agree to if they want to log on state lands; if you don’t follow best practices, you can get shut down.
Pratt’s Forest Management has a good relationship with the state — and thanks to growing demand for firewood, Jordan Pratt says the business is in good shape, too.
“Nowadays we pull a lot more low-grade [wood] than we do high-grade wood,” he says.
And as far as forest management — and local jobs — go, that’s a good thing.
“I think this market, the firewood market, has helped a lot of loggers survive,” Don Pratt says. “It got to the point to where, [loggers would ask] ‘Do we go to work today?’ Your older generation pretty well creamed most of the high-grade logs, as far as I was concerned.”
“There was no market for firewood. They couldn’t make a living off it,” Jordan adds. “Nowadays, it’s, for us, our firewood is more what we make most our money on.”
Don hypothesizes that the “younger generation” is having an impact, too, with their energy choices.
“They just don’t want to see coal being burned, oil being burned. If it’s not renewable, don’t do it,” he says. “It’s just like watching all these solar panels going up. It’s no different. I think this is just the beginning of it.”
Inside an automated woodchip boiler plant
It’s not just individuals who have grown more interested in wood heat. Institutions have too, including Goddard College in Plainfield.
The college was built on a 200-year-old farm, and most of the buildings here are antique. But up one snowy gravel road is a big, brand new building. The siding looks fresh from a lumber yard, and smoke billows out of the chimney. Inside is a large, state-of-the-art woodchip boiler plant. It opened at the end of the year. Its single furnace heats 21 of Goddard’s 23 heated buildings.
Until recently, Scott Blanchard was Goddard College’s facilities director. He recently took a job with Messersmith, the Michigan company that manufactured this boiler. Scott spent the last decade at Goddard, making this plant a reality. Scott beams behind his beard and baseball cap. He points to two sensors, which face each other through a transparent bin of woodchips.
“This is what tells the machine to go, this sensor,” he says.
Everything is automated, in a beautiful kind of industrial choreography. Sensors tell a motor to move an auger. The auger pulls woodchips onto a conveyor belt, which travel up into the bin, and then into the furnace.
Next to the furnace, Scott points out a big metal tank.
“This is what keeps it clean burning,” he says.
The tank, Scott says, captures tiny particles of tar, soot and chemicals that would otherwise go up the chimney. The idea is to reduce air pollution. This so-called “electrostatic precipitator” was not required, and made up a third of the project’s $2.5 million cost.
“A fuel stove like you have at your house probably burns at 40 percent efficient. This burns at, like, 93 percent efficient,” Scott says with pride.
Before there was the boiler plant, every building at Goddard had an oil furnace. “We were burning 62,000 to 65,000 gallons of fuel oil a year,” Scott says.
It was expensive. Especially during the early 2000s. Then, in 2007, Goddard College signed on to the American College & University Presidents’ Climate Commitment. Scott says “it was basically a commitment to reduce our carbon footprint, our carbon usage.” Goddard’s goal was to be carbon neutral by 2020.
Thus the college started down the path toward a wood heat. Scott says it was premised on the theory that “any carbon that you do release is re-sequestered. You know, if you cut a tree down, another tree is gonna grow. So theoretically it’s carbon neutral.”
But not everyone thinks wood heat — even high-tech boilers like this — are a good idea.
A neighbor's concern
“You see these two big trees going up in the field?” asks Rhea Wilson, motioning through some sliding glass doors and across her backyard to the boiler plant, some 300 yards away. “That’s the building."
Rhea was briefly vice president of Goddard College, back in the 1970s. But she and her husband first learned about the project at a community meeting for Goddard’s neighbors. This was roughly a decade ago.
“And actually my first thought, like everybody in Vermont, was, ‘Oh what a nice idea,’” Rhea recalls. “Everybody was saying that it was renewable, and green, and much better than oil, and why not?”
Then, Rhea says, she started doing research, “and the first thing I think that we came into were the health worries, because of the particulates and all that sort of stuff.”
Rick, Rhea’s husband, has lung disease. And as Rhea researched wood boilers, she started reading about what happens in the body when you breath the tiny particles in wood smoke. She read that even operations like Goddard’s might not be capturing the tiniest — and possibly most dangerous — particles.
But it wasn’t just air quality Rhea and Rick were concerned about.
“As we’re learning about that we’re learning that on the CO2 stuff, on the global warming stuff on the carbon — it’s awful,” said Rhea. “In fact in the middle of all that research, we took out the wood stove that we had in the house, because we got so worried about the health issues and the environmental issues.”
The Wilsons replaced their wood-burning stove with liquid gas — propane. And they joined with neighbors to try to get Goddard to move the plant further from their neighborhood. The efforts delayed the project, but ultimately failed.
'Where it hurts': Air pollution and health effects
The pushback to wood heat isn’t limited neighbors and their NIMBY concerns. It’s actually something our question-asker Coco is also wondering about.
Coco says last winter she got a job working for a guy who has a blog promoting wood heat, including automated pellet boilers.
“I started sort of helping him do a little outreach to other environmental organizations, and started to become really aware that not everybody’s on board,” Coco says, “so I think that it’s not entirely clear… where it’s helpful and where it hurts.”
To find out where wood heat hurts, and if Rhea Wilson is right to call it “awful,” we call up Zoe Chafe, a postdoctoral associate and researcher at Cornell University.
Zoe has a Ph.D. in energy and resources and a master’s degree in public health. She was the lead author on a World Health Organization report about the health impacts of wood heat, and she was a chapter scientist for the International Panel on Climate Change’s 2014 Fifth Assessment Report. Her chapter was on climate change and health. In other words, this is her bailiwick.
“We’re most worried about the tiny, tiny little particles,” she says — the bits of matter in smoke that are smaller than 2.5 microns wide. These are called PM2.5.
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“What happens is that the particles can go deep into our bodies. And they can travel so deep into our lungs that they actually cross over into our blood and the smallest ones can even go into our brain,” Zoe says. Studies show these compounds can be carcinogenic, and they can lead to and exacerbate heart disease, lung disease and asthma.
“In the health community we are certain at this point, I mean all evidence points to the fact that there is no safe level of exposure to particulate matter, to PM2.5. And so even down to the very lowest levels that we can measure, it’s better to be exposed to less PM2.5 rather than more PM2.5.”
Zoe says breathing wood smoke is worse for kids, elderly people, and anyone with heart or lung problems, like Rhea Wilson’s husband Rick.
We asked Zoe if she ever felt like a grinch, telling the world that wood smoke is actually bad for them.
“Absolutely, all the time,” she said, laughing. “It’s a hard topic to work on because it’s not a fun thing to communicate. I really do enjoy having wood fires.”
There are some moderating factors, however. For one thing, if you live on a hillside like Coco and Emmet Moseley do, the smoke may blow away from your house pretty quickly. And if it doesn’t, it’s not a permanent air pollution. Eventually, the particles will fall to the ground.
But the particles don’t stop doing harm when they fall to the ground. They can be bad for the earth, too. Particularly (no pun intended) the particulate known as black carbon.
“That stuff is pretty worrisome, especially in areas like Vermont where there’s a lot of snow on the ground for part of the year,” Zoe says. “We’re worried about the black carbon falling on the snow and reducing the reflectivity of that surface.”
Usually snow reflects heat back into the atmosphere. But when black carbon lands on it, the carbon absorbs the heat, melts snow and contributes to climate change. On top of that, wood smoke contains other things that are bad for the environment, like methane.
Of course, no matter what you burn, you’re going to emit smoke. But as far as pollution is concerned, wood is nearly as dirty as coal. Which is weird, because incentives for modern wood heat projects, including the Goddard plant, come from the state’s so-called Clean Energy Development Fund.
But that’s a story for another day.
Superior wood heating
All the drawbacks aside, there is some good news: Not all wood heat pollutes equally. So if you heat with wood, how you do it can make a big difference in air quality.
“I always like to point out this one statistic, which is that residential wood-fuel users use 53 percent of the wood that’s burned in the state. But they create 94 percent of the particulate matter emissions,” says Wood Energy Coordinator Emma Hanson, citing numbers from the Vermont Department of Environmental Conservation Air Quality Division.
Emma says the statistic means two things. One, the big installations, like Goddard College’s, actually burn quite cleanly. “And the other takeaway is that residential users really need to up their game,” she says.
As in, most of us are burning super outdated stoves. Or green, moldy, treated or painted wood that smokes and smolders instead of burning hot. Or some/all of the above.
“As you're driving down the road and you see smoke coming out of chimneys, that's a sign that something isn't going perfectly right in that stove,” Emma says. “It looks so homey, and like it’s out of a Norman Rockwell painting, but it's not good for air quality.”
But there is hope! Because burning wood in 2019 doesn’t have to be this way. Emma talks through three categories of superior wood heat:
The modern wood stove: Newer stoves are much better than old stoves. Many of are certified by the Environmental Protection Agency for how cleanly and efficiently they burn. “If you're not sure [if your stove is EPA-certified], if your stove was before 1990, it's not ... So that's kind of the general cutoff.”
(Important PSA here: Your luxurious open fireplace? Unfortunately that is a huge guzzler of wood, and actually pulls more hot air out of your chimney than it puts in to your living space. “A fireplace is the antithesis of a heating appliance,” Emma says.)
The wood pellet stove: Instead of burning cordwood, the pellet stove runs on little pellets of processed wood. You buy them in big bags, and they kind of look like rabbit food. “And so that's a little bit more user-friendly than a cordwood stove, because you can just load it ... and it might run for as long as three days depending on how large your hopper is.”
The wood pellet boiler or furnace: What’s cool about this technology is that if you have a conventional boiler or furnace, you can actually switch to wood pellets without having to replace all your pipes, baseboard, etc. “It works exactly the same as your propane or oil system does now. Meaning that a truck pulls up to your house, a guy or a girl gets out and hooks up to your house, delivers fuel once or twice a year. Then with a touch of a thermostat you heat your home with said fuel, and that's it.”
Residential pellet boilers do have slightly higher particulate emissions than oil or propane boilers. But the pellet boilers are a big leap ahead of the old wood stoves. According to Emma, one non-EPA certified wood stove creates as much particulate matter emissions as 200 pellet boilers.
And it’s not just about emissions. Say you get a new wood stove. You might be burning half as much wood, which saves you time and money.
Now, upgrading to a new wood stove or a pellet stove or a pellet boiler isn’t cheap. So to encourage Vermonters to make the switch, and help meet our renewable energy goals, Efficiency Vermont and the Clean Energy Development Fund are offering financial incentives right now. You can save anywhere from $800 on a wood stove to $6,000 on a pellet boiler — $7,000 if you’re a Washington Electric Co-op member.
The carbon question
A brief recap: Wood heat is local and affordable. And using wood for heat creates demand for wood, which can keep loggers employed and developers away from forests.
But wood smoke does pollute, and that affects the environment and human health. However, if you burn the right wood the right way, you can reduce the amount of pollution. And, if you’re like the Moseleys and you live far away from any neighbors who may suffer from asthma or lung disease, air pollution may not be a major factor for you.
“Maybe this is a good time [to ask]: What is our ultimate goal, or what are we measuring?” says Andy Friedland, a forest ecosystem scientist at Dartmouth College. “I argue that what we ultimately care about is carbon dioxide concentrations in the atmosphere.”
Carbon dioxide. Andy says because forests grow back in New England when they are managed well, it’s fair to say wood heat is generally renewable. But, he says, whether wood heat is carbon neutral is a different question.
And, just a warning, we’re gonna specific with the science. Stay with us!
First of all, “coal and wood are about the same in terms of their carbon,” Andy says, if you’re strictly talking about how much CO2 is released per unit of energy. “Most people don’t realize that.”
Much of the carbon will be reabsorbed if a new tree is allowed to grow in its place. But that takes roughly 60 to 100 years. And, Andy says, we may not have that much time.
In October, the U.N.’s panel on climate change released their latest report on climate change. It suggested we humans need to reduce greenhouse gas emissions dramatically over the coming decade. If we don’t, we’ll face higher sea levels, more drought and more days of extreme heat.
“The trouble is,” Andy says, “it might take 60, 80, 100 years for that tree you cut down to be replaced by a tree of equivalent size. So what about in that intervening 100 years? And what about today, when, if you agree with me that climate change is an extremely important issue, if not the most important issue, facing humanity. What do we do in that intervening time?”
On top of that, Andy says cutting wood speeds up the emission of CO2 in a way that growing a new tree won’t help. First, he explains, cutting trees lets more sunlight into the forest, which speeds up decomposition, releasing more carbon into the atmosphere. Next, Andy says, scientists are increasingly realizing that cutting trees also affects the carbon stored deep in the soil. It turns out cutting trees releases that carbon into the atmosphere as well.
So, Andy says, burning wood for heat is not carbon neutral. Though if you have 60 to 100 years to wait, it’s a lot closer to carbon neutral than burning fossil fuel.
“But wait a minute!” Andy interrupts.
He’s not saying you should stop burning wood. We live in Vermont, we need heat, and as he puts it, “no energy source is clean.” In fact, this is one of Andy’s favorite mantras: “All energy choices are lousy. So don't tell me about that clean solar energy that's coming from your backyard.” (Andy discloses that he has a solar tracker in his backyard, but points out that “there was energy needed to make it.”)
Like a lot of people we talked to for this episode, Andy is fond of diversification. He has solar energy, wood heat and an oil furnace at his house. But he says the most important thing you can do to reduce your carbon emissions is be efficient. Turn down the thermostat, insulate your home, and if you can, upgrade your technology for efficiency, whatever your fuel.
“It could well be in certain circumstances,” he says, “using wood might be the best of a lot of lousy alternatives.”
On coziness and our elemental existence
After reporting this episode out, we give Coco Moseley a call back to tell her what we’ve found.
After hearing us through, Coco says this: “There’s no way that we would change and not burn wood.”
“You know,” she goes on, “I probably would be criticized in terms of the environmental lens that we’re talking about, but I feel like with the wood stove, I just feel warmer.”
Coco says she and her husband Emmet have been talking about getting a new, more modern wood stove. And, they’re insulating their basement, too. But the more she thinks about it, the more she feels this way:
“It makes winter in the Northeast kind of tolerable. Because you have this central hearth. Which, I think, kind of gets at some sort of elemental existence, for us, and for humans in general. Fire equals warmth. Whereas just turning on a thermostat, I don’t know if it has the same kind of heart.”
We can quantify carbon and efficiency and air quality until the flames die down. But coziness: How do you measure that?
We re-released this episode in our podcast feed on Friday, Nov. 6, 2020. When we checked back in with our question-asker Coco, we received this update:
We did some renovations to our house, opening up the downstairs and insulting our basement and attic. We also upgraded to an efficient and cleaner burning hearthstone wood stove. We still heat primarily with a wood stove but also have a heat pump for back up or supplemental heat.
So much of this work was propelled by what we learned from Brave Little State. We wanted to keep hearing with wood, but we knew we had to do it better.
We are doing well. Louisa is two (!) and enjoys stacking firewood. I started a new job as the Library Director for Bristol and we have wood moisture meters available for patrons to test their firewood’s dryness! I still think about heating with wood frequently.
Listen to the original audio from 2019 here:
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Special thanks this month to Jake Marin, Diana Frederick and Amy Noyes. Our editor is Lynne McCrea and our theme music is by Ty Gibbons. Other music in this episode was used under a Creative Commons license: