for National Geographic News
Burning trees for power may seem backward, dirty, and environmentally hostile.
But a high-tech new way of wood burning holds great potential to save energy, cut costs, and even fight global warming, a new study says.
For example, in the United States wood could sustainably supply "enormous amounts of energy, comparable to power production from hydroelectric [dams]," says the study, to be published in tomorrow's issue of the journal Science.
Already, "advanced wood combustion" is powering a U.S. college and cities across Europe, such as Joensuu, Finland.
Joensuu's "air quality has improved greatly," said city resident Antti Asikainen, a forestry expert at the Finnish Forest Research Institute. "It's a really clean technology."
The city of roughly 58,000 "is heated with a wood and peat mixture, which has replaced small fireplaces and oil burners—they're the worst generators" of pollution, Asikainen said.
To get these wood-burning benefits, cities can't rely on ordinary furnaces.
In advanced wood combustion power plants, intense heat and carefully controlled conditions ensure that nearly all the carbon in the wood is broken down into flammable gases. Then the gases are ignited, burning much more cleanly than a typical smoky home fireplace.
The heat from burning the gas can be used directly for heating or to generate electricity.
The power plants also have filters that remove many of the small particles that come from burning the wood, greatly reducing pollution.
Wood Is Green?
Another early adopter of advanced wood burning is Middlebury College in Vermont, which opened a wood-fired power plant last month.
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