"Renewable energy" means wind turbines on the prairie or solar panels on urban rooftops, right? Well, yes, but better add to the list the burning of wood and wood byproducts in the furnaces of pulp and paper mills. That is the nation's largest source of renewable energy aside from the massive hydroelectric dams that, because of their impact on river ecosystems, are not environmentalists' favorite choice for power.
Take out wood burning and hydroelectric, and renewable energy's share of the U.S. energy mix falls from the low 7 percent we recently charted to less than 2 percent. Here are a few things to consider about wood burning:
1) Wood is contributing 2.1 quadrillion Btu to national energy consumption, nearly 10 times more than wind power and nearly three times more than the ethanol with which it is usually lumped together (both are considered "biomass"). Nearly all of the wood burning is carried out by the timber industry, as it seeks to use its own waste products to satisfy a portion of its large energy needs.
2) The environmental verdict on wood burning is mixed. There's new research on how wildfires contribute to greenhouse gas emissions. And yet, some view tree burning as carbon dioxide neutral because the carbon emitted in burning (which would have been emitted slowly, anyway, when the dead tree rotted) will be absorbed again when new trees are planted. Great Britain even hopes to cut its carbon emissions by burning more trees.
3) It's safe to say the ecofriendliness of wood burning depends greatly on the forestry practices and entire life cycle of trees being used for fuel. Some interesting online discussions appear at Seacoast NRG and the National Geographic's Green Guide. It's also important to remember that without proper pollution controls, wood burning can unleash particulate matter and carbon monoxide emissions that can be harmful to health.
4) Environmental groups haven't focused much on the pros and cons of wood burning, but they'll probably have to as the global warming policy issue advances. Many states already have renewable portfolio standards, requiring that utilities use a certain percentage of renewable energy. If a nationwide standard, like the one now under consideration on Capitol Hill, is ever adopted, it is quite likely that utilities in the Southeast would take a closer look at wood burning as a way to meet their quota. The calm southeastern air is practically bereft of what's known as "wind-power resource." But in Georgia, the wood-burning answer may begin to look as sweet and clear as moonlight through the pines.