2012-03-13 What About Wood Heating

A series of columns on home design and home heating with a view to energy efficiency would not be complete without a discussion of the potential wood has for heating our homes.
Mary and I heat our home with wood. We like it. It helps us maintain our connection with the earth that supports us. This connection with the earth is so much more vivid when I am splitting wood in the morning or watching the flame in the glass window than if I were simply to set the thermostat higher and feel the heat come out of the forced air register of a natural gas furnace. For me that is one up side to heating with wood. The satisfaction I get from heating with wood is similar to that of growing the vegetables I eat.
But heating with wood is also energy efficient. We need to learn to pay attention to a new insight called EROEI (energy return on energy invested). When oil was first discovered in the 1930s, the EROEI for that oil was 100:1. Now all the readily accessible oil is gone. We are now developing the tar sands where the EROEI is only 5:1. If I apply that insight to wood heat, I consider the fuel used by my chain saw and my pickup truck. If I get my wood fuel about 45 km from my home, the EROEI is about 24:1. So for residents of southeastern Manitoba, where there is plenty of bush and forest, wood fuel is one of the most efficient sources of home heating.
Furthermore, as we become increasingly dependant on hard-to-get-at oil supplies, notably tar sands and offshore oil, the price of oil-based fuels is going to become increasingly volatile. There is comfort in being dependent on a local fuel resource, wood, the price of which is likely to be considerably more stable in the years ahead.
Now before we all run out and install wood burning heaters, there are some cautions to consider. Wood heaters produce smoke. Outdoor wood boilers are the biggest culprits in this regard. New, certified, indoor wood heaters produce much less smoke. In the last twenty years much research and development has gone into the development of improved heaters. The results are impressive. Nevertheless, where there is a wood fire, there is at least some smoke. If everyone in Steinbach heated with individual wood heaters, we would likely have an air pollution problem. A comprehensive solution to that problem exists and that is district wood heat. In Scandinavia, district wood heating is common.
Maintaining a wood fuel supply is labour intensive. That human energy is not included in the EROEI. This is because human energy is not fossil energy; it can be replaced. Furthermore, much, if not most of the labour going into the maintaining of a wood supply is wholesome energy, energy that ought to be expended in order to maintain the health of our body. Maintaining a wood fuel supply is good, healthy, outdoor exercise.

-- Eric Rempel