"Combined heat and power" (CHP) is catching on. Just a few years ago, when I was doing graduate work in urban sustainability, it was a bit of a challenge to find new information on CHP (also known as cogeneration) outside specific industries, especially in the United States. Today it's virtually mainstream, among both governments and business. Do a Google News search on the term and you'll come up with around 10 articles per day on it.

District heating --heating multiple buildings with centrally-produced heat (often from a CHP plant)-- is also gaining in popularity. Many European cities, with their denser urban cores, are natural spots for district heating. There's a long history of district heating in some major American cities, though, and event lower-density neighborhoods like one in Portland, Oregon are potential candidates.

CHP and district heating are exciting not only because they are far more efficient than conventional practices -- they open up exciting possibilities for the relocalization of community energy supplies. We've posted more than a few articles over the last two years on Växjö, Sweden and its local wood-fired central heating plant. Now other communities and institutions are investing in locally-fueled power, from a college in Vermont (burning wood) to the largest supermarket chain in the UK (burning straw). Newer technologies like mini- and micro CHP are now becoming commercially viable and, despite hard economic times, venture capitalists are still paying attention.

Still, shifting dependence from a global fuel like oil to a locally-produced energy source is not without its complications and risks. Sweden actually imports --from as far away as North America-- some of the wood it burns in its CHP and district heating systems. The city of Woking, England boasts a local network of small natural gas-fired CHP plants which could also burn locally-produced methane -- but what happens when England has a natural gas crisis (a much likelier scenario for the UK and Europe than North America) and there's a national scramble for local bio-gas?

Should Sweden reduce its energy needs to within the limits of what its own forests can provide? Probably yes. Should Woking have invested in a less economically volatile fuel or a different technology for its power and heating system? Maybe, maybe not. Local leaders all over the world make decisions with the information they have, and in the face of uncertainly --whether about the future of natural gas supplies or the viability of new technologies-- they still have to make decisions. Only time will tell if Sweden and Woking could have made better decisions, but by investing in non-petroleum energy early, they'll still reap far more benefits than those nations and cities that haven't.

Photo credit: Derek _______

» 581 reads | login or register to post comments