Backing Up Wood Boilers
I like wood heat for lots of reasons, not the least of which is that it makes good environmental sense when done properly. A reader from the East Coast challenged my recommendation of the new breed of clean burning outdoor boilers (“Outdoor Wood Boiler’s Part of a Sustainable Future“) with some very reasonable concerns. He also called into question my claim that wood heating is carbon-neutral and makes no overall contribution to the greenhouse effect. I hear these concerns often, and this was my answer:
“You’re right about some outdoor boilers using a lot of wood. But the good ones (like the wood gasification units I wrote about), include lots of heat exchange passages to extract the heat from the exhaust stream. The models I’ve researched use 75% less wood than many older models, and they emit no smoke.
As far greenhouses gases go, a properly harvested forest grows more vigorously than an over-mature one, removing more carbon from the atmosphere. Forests can be poorly managed, but in many parts of Canada it’s possible to heat with wood while never cutting down a live tree. I’ve done it at my place for 20 years. I can’t even begin to keep up with the trees that blow down in wind storms or are taken down by beavers. Although heating with wood doesn’t always yield improvements in the greenhouse gas situation, it certainly can. On the other hand, burning natural gas or oil (or using fossil fuel generated electric) always results in greenhouse gas emissions, no matter how cleanly these fuels are burned. The release of new carbon into the atmosphere is inevitable in these cases.”
Some European countries are way ahead of us in the greenhouse gas issue, and they use wood pellet heating extensively, even in urban situations. Wood heating isn’t the answer for everyone, but in the right circumstances, done in the right way, it’s definitely part of the solution.