Science Scene - Biomass going to the Woodshed

When discussing renewable energy, you’re likely to hear a lot about wind, solar, geothermal and hydropower. You're likely to see the conversation turn to nuclear power (not renewable, by the way, but also does not produce greenhouse gases) before anyone mentions one of our oldest and humblest renewable sources of energy – wood.

But the good old American log – the energy provider of choice in the United States before coal became king in the 1880s – could make a comeback as the hottest renewable around.

According to an article in Science, from researchers at The Nature Conservancy, Duke University, Resource Professionals Group, USDA and the and the Austrian Chamber of Agriculture, advanced wood combustion (AWC) facilities could help the United States
Reduce our dependence on foreign oil, cut greenhouse gas emissions, and create jobs.

What we need is a more localized energy system that provides power to communities from within the community over short distances. This can work through AWC, the authors say, because the systems release minimal amounts of sulfur oxides, mercury and other pollutants. It turns out wood is much cleaner than coal. Modern AWC facilities – common in Europe – also approach 90 percent thermal efficiency.

AWC provides lower emissions through efficiency — efficiency in burning and transmission. Because the energy does not have to travel as far, you get more bang for the log. AWC also takes advantage of CO2 that’s already in the system, recirculation CO2 already in the biosphere’s carbon cycle. Fossil fuels, on the other hand, introduce more CO2 into the system when they are burned.

If communities get smart about AWC, they’ll have to build new facilities and reconfigure transmission lines – both of which would create jobs. There will also be new employment and training opportunities for electricians, steamfitters and plumbers (not to mention foresters) to ensure that this new source of power does not diminish our forests.

Forest management is the key to making AWC work. Fuel for these plants must come from sustainably managed forests. This is not only essential for the ecosystem, it’s also essential for the AWC plant – it’s useless without a sustainable supply of wood to feed it.

But the wood does not need to come from forests alone. The researchers point out that the United States produces 30 million tons of combustible urban wood a year from storms and construction site debris. That material is often thrown in a landfill, but could be used to produce energy for urban areas.