Pellet stoves: a good heating option?
They have higher upfront cost but lower long-term carbon, and they could save you money.
Tue, Jan 06 2009 at 3:20 PM
My brother recently bought a pellet stove and swears it's saving him money and heating the entire bottom floor of his house, but he also usually won't admit a mistake. I'm cold-natured and I can't put up with a chilly house, but I do want to save money on heating. Can a pellet stove really heat that much of a house and be worth the effort?
— Freezing in Frisco, Colo.
Yes and yes.
Burning wood pellets can replace your electric furnace, and provides as much heat as you want or can afford. And while it's less efficient than an electric furnace, it's as or more efficient than other common heat sources like oil, natural gas, propane and coal.
That was simple.
Which means there must be something amiss. It can certainly be easy being green, but it's generally not simple. The equations for being green tend to get complicated. Let's add other pellet-heat issues to the computation: cost-effectiveness, pollution and sustainability.
(See below for things to consider if you want to buy a stove.)
The U.S. Energy Information Administration puts the cost of heating by pellet in a range between coal and natural gas, and well below oil, propane or electric. This means that on a BTU-per-dollar basis, pellet heating is considered cost-effective. The EIA's tally doesn't seem to include the electric cost of running a pellet stove (they are, after all, electric devices), an average of $10 per month. The initial cost of buying and installing a unit is high, they require regular maintenance, and the growing demand and shrinking supply for pellets is raising costs — things to factor into a cost-effectiveness formula. How long would it take to recoup your investment? That depends on what you buy, how you use it, what it's replacing and your local utility rates.
There's no doubt pellet stoves offer vast improvements over their wood-burning predecessors. They're much cleaner burning than woodstoves, but less so than gas furnaces. The amount of particulates (think asthma and allergies and other respiratory problems), carcinogens and carbon monoxide emitted by burning pellets is a fraction of that for burning wood, even with newer EPA-certified wood stoves. In fact, the EPA considers emissions from pellet stoves low enough that they're not even subject to certification.
Wood pellets are made from compressed sawdust, bark and other lumber leftovers. They can also be made of corn, soybeans, nutshells, cherry pits or agricultural "waste," and stoves vary depending on what you want to burn (wood, corn, and multifuel stoves are available).
Because pellets are made from renewable resources, and may keep some mass out of landfills, they're usually considered a good environmental choice. Claims that these biomass pellets are carbon-neutral may be a bit misleading, though: They can't emit more carbon than they absorbed over their lifetime, but the carbon used to grow, transport, package and process the pellets should be included in the calculation. Keep in mind, too, that a pellet stove is an electrical appliance, so the energy used to drive the stove must be added to the pellet heat's carbon footprint.
And while pellets are made from renewable resources, there's no guarantee they'll be renewed (that is, replaced). A new tree can be planted for every tree felled, but there's a big gap between a full-grown tree that was already absorbing CO2 and a tree that might be planted and might eventually grow to absorb as much CO2.
And corn ... don't get me started. The way we grow corn in the United States leaves us not with a renewable, carbon-neutral crop but rather something like fossil-fuel belching expanses of monocropped diabetes. Some of these negatives can be offset by buying pellets whose ingredients originate in sustainable tree and crop farming. And, of course, local is better.
Sound extreme? I haven't even started on the fuel vs. food aspect.
Even with the environmental costs of transportation, production and packaging, pellet stoves generally are an efficient heat source. And with low environmental expense compared to many of the other options, they're a legitimate piece of the sustainabilty puzzle. In many ways, as with ethanol and biodiesel, pellet heat comes down to a supply issue. On a local, finite scale pellet heat ranks well as an efficient and sustainable option. But (there it is again), we live in a world of shrinking resources, and ever-expanding consumption, where crops that could be the base for renewable energy are in competition with our basic needs: food and water.
As it stands now — on that local and finite scale — pellet heat can do wonders: divert "waste" from landfills, provide fairly efficient and clean heat, and offer a method of achieving sustainable, independent energy systems.
What it can't do is remain sustainable on a large scale. Not on an overpopulated planet where we often seem bent on monocropping and poisoning ourselves out of existence. There's only so much sawdust to be compressed, nutshells and cherry pits to be burned, corn and soy to be subsidized for pellets. And pellet manufactures are only one of a growing number of ventures sucking up that sawdust. Who should get first dibs on these "waste" resources?
If it were up to me, it would go where it never was a waste: back where it started. It takes 100 years to make one inch of soil. When agricultural "waste" gets burned for fuel — adding insult to the injuries of overcultivation, tillage and the chemical sterilization of land — we ultimately ensure that biomass fuels won't be a fuel of the future. No soil, no trees. No soil, no corn. Or soy, cherry pits, olive pits, corn husks, stalks ...
It comes down to biofuels — whether in the form of pellets or biodiesel, they have an important role in fighting global warming. Cultivated, manufactured and distributed in balance with what a given area can sustainably sacrifice, biofuels are vastly preferable to their fossil ancestors. Only you can judge if a pellet stove is right for you, but I hope I've helped you make an informed decision.
Moral of the story? No single fuel source will get us out of this quandary, and just about anything that replaces coal and other fossil fuels is a good option. And, most importantly, any fuel source is sustainable only in relation to its consumption. The best alternative fuel is conserved fuel. So, whatever your heat source, put on some thick, cozy socks and a sweater and save, save, save!
Keep it green,
- Requirements: The standard "need" for heating is considered 25-30 BTU/h (British thermal units per hour) per square foot — or 5,000 BTU/h for 200 square feet. This is an average, so calculate the amount of space you want to heat, how well it's insulated and your climate (average outside temperatures).
- Power: Pellet stoves require electricity, and need to be connected to the electric grid, or to a backup generator or battery. You don't want to get caught with the stove running during a power outage (trust me).
- Cost: There's a wide range for the stoves themselves (minimum will run you $1,000 installed, but that's optimistic). You may need a hearth pad. On average, people use three tons of pellets over the winter months, at about $200 a ton. Calculate the cost of annual maintenance, and, because pellet stoves have many moving parts and vulnerable electronics, plan on repairs.
- Availability: There were widespread shortages in 2005, with wait lists of months to get pellets (of course, by then it was spring). I don't know about current supply issues, but I do know there are close to 1 million people using pellet heat in the United States, and demand rises as energy costs rise.
- Storage: You'll need a dry space to store the pellets. If you burn corn, you also need to make sure your storage is bug- and rodent-proof. Space becomes more important when considering that pellets are cheaper by the ton and lessons from previous shortages have led people to stock up large quantities.
- Maintenance: The stoves are more hands-on than most of the heat sources we're used to. Not a bad thing, by any means; just keep in mind that you'll need to do a minimum amount of cleaning and maintenance (clean the heat exchanger, venting system, traps and glass; empty out the ashes; and, of course, load the hopper).
* Pellet stoves are at least as efficient as heating directly from fossil fuels, according to the Energy Information Administration Heating Fuel Calculator and the Department of Energy's Energy Efficiency and Renewable Energy Consumer's Guide. I swear, government programs get their funding based on how many words they can fit into a name.
* BTU (British Thermal Unit) is used to describe the energy content, in this case the heat value, of fuels.
* I read a blog post somewhere (sorry, no link) by a woman who's heating with corn. She gets it from a nearby organic farm that grows the non-GMO crops sustainably. That's gotta be about as good as it gets. But how many of us have that option? I live in a city, my HVAC is functional (making a pellet furnace financially extravagant), and our winters are relatively short (increasingly so). No pellet heat for me. I do, however, run my car on biodiesel (how did we get from wood-pellet stoves to biodiesel? Same sources, same carbon issues, same sustainability issues). Most biodiesel comes from virgin crops, grown in industrial-agriculture fashion, bound for the fuel tank (substitute pellets for biodiesel, especially as demand goes up and "waste" becomes rare). The biodiesel I use is made from used cooking oils, gathered from local restaurants and institutions, and processed locally. The waste product is glycerin (soap!). My version of the perfect-pellet scenario.
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