Thomas Homer-Dixon is a smart Canadian with some keen insight on the problems that our species face. His book The Upside of Down is an exploration of the biggest threats facing us and the planet. Two of his top five are the problems that I think will have the most influence on our way of life this century: Peak Oil and Climate Change.
One of his observations is that our support systems are much too brittle. Take food, for example. What would happen if there was a massive, North America-wide diesel shortage in February. How long would it take for Edmonton to be in big, big trouble? We have no resiliency in our food system. It relies 100% on the widespread availability of cheap diesel fuel.
The picture above is a Scan Andersen 10 wood burning stove. We are having one installed on the main floor of the Mill Creek NetZero Home. NetZero energy homes are a brilliant idea, and I hope that they spread like wildfire. However, they, like almost every aspect of our lives, depend very heavily on abundant fossil fuels. Our ventilation system, our solar hot water system, and even our solar panels depend on there being juice in the grid. So what happens if the juice runs out one day?
Having a wood burning stove in our home gives it resiliency. No matter what happens to the fossil fuel grid, we will be able to keep it warm (uh, if we have the wood, that is).
Anyone building a NetZero Energy home goes through the same process. Once you've eliminated 90% of the need for heat, where does that last 10% of heat come from? The Riverdale NetZero Project is attempting to store summer solar energy in a big hot water tank (a swimming pool, really). We've decided to just use straight coal-powered electricity to heat our house in the dead of winter. There is no perfect answer, but it's impossible to ignore the simplicity of the oldest form of human-used stored solar power:dead trees.
The wood that we'll burn in our stove will be salvaged from construction waste or trees that were going to be cut anyway. Its carbon will be released to the atmosphere either way, so it may as well let us displace some coal that we would have needed to use for heat anyway. So wood is a carbon-neutral heating option. It's not the greatest for ground-level pollution levels, though.
image courtesy of treehugger.com
The above image shows the difference between the ground-level pollution emitted by an EPA-Certified Woodstove (which the Scan Andersen 10 is) and a gas furnace.
We've decided that, since the Mill Creek NetZero Home will burn much less wood than depicted in the picture - about 3/4 of a cord of wood vs. 6-10 cords for a conventional house - and since our household is car-free, the pollution burden is acceptable for us to impose on the neighbourhood. We chose one of the cleanest stoves out there. The Scan Andersen 10 is rated to emit 3.13 grams of particulate matter per hour, and it's 78% efficient at converting wood to heat. Plus we'll make sure to burn only really dry wood for a cleaner burn.
The stove will be surrounded by concrete floors and in front of a brick mass wall, so the heat it projects will be absorbed and slowly released over the course of 24 - 48 hours. It will be beautiful to watch, and the heat quality will be very pleasant. I can't wait to fire it up for the first time. And I can't wait to see my first dumpster full of old dry 2x4s next summer. We'll essentially be converting construction waste to electricity, which is a pretty great way for a tree hugger to keep warm.
(cross posted at www.raisingspaces.com)