Wood chip-heating solution is not backed by science

Posted: Thursday, November 12, 2009

There have recently been stories in the news media touting plans by the U.S. Coast Guard to use biomass to heat federal government buildings. In his inaugural speech, President Barack Obama made a commitment to "restore science to its rightful place."

Unfortunately, the proposed conversion of Coast Guard bases in Ketchikan, Kodiak and Sitka to wood-chip heating using centralized burners propels the scientific approach to clean, renewable energy policy in the wrong direction. The Coast Guard has come to the wood- burning proposal honestly, however, errors abound in the acceptance of the hypothesis that wood from the forests of Alaska is a clean, renewable, carbon- neutral source of energy.

Simple observation confirms that Southeast Alaska contains the nation's largest national forest, the Tongass National Forest. However, scientific analysis reveals that the Tongass is the storage facility for 8 percent of all carbon stored in forests throughout the United States and 0.25 percent globally (Ecosystems (2006) 9: 1051-1065.)

The Tongass also excels at removing carbon dioxide from the atmosphere, separating the carbon from the oxygen, storing the carbon in the soil, trees and other vegetation, and reintroducing the oxygen into the air. Whether the source of wood chips for burning comes from old-growth or thinning second-growth trees, the result lays waste to the vital service the Tongass provides, removing and storing carbon.

The Coast Guard has not taken into consideration that wood has more carbon per unit of energy than oil, about as much as coal, and that the moisture content of Tongass wood chips makes the equation of carbon per unit of energy even less appealing. Lack of consideration for other ways to heat buildings is even more disturbing because the three Coast Guard bases are close to tidewater and could serve as demonstration projects for how heat pumps - with either seawater or the ground as a heat source - could be used in these three representative federal facility locations. Wave, tidal, wind, solar and geothermal power generation technologies are available for development in Alaska and do not involve combustion of a fuel and release of carbon. Heat pumps are proven clean, efficient heaters that are a perfect fit with the Southeast region's abundant hydroelectric capacity.

So what is a heat pump? It is a device that uses a small amount of electricity to extract a much larger amount of heat from a cold place and then concentrate it to a higher temperature. One unit of electric energy put into a heat pump produces three to four units of heat at a useful temperature. This is 300- to 400-percent efficiency. Heat pumps are close relatives of refrigerators and freezers that extract heat from the cold freezer box and radiate it from the coils on the back of the unit. This is 20th century technology.

The Coast Guard Civil Engineering Unit Juneau, working extensively with the Forest Service and the Department of Energy, are proposing an 18th- century solution for a 21st-century problem that developed out of an 19th-century solution.

The solution being proposed adds to the problem rather than solving it. Biomass, no matter how clean-burning the combustion process, is still a combustion process that releases carbon dioxide into the atmosphere. The way the biomass would be acquired would not only release carbon currently stored in the Tongass, it would reduce the future capability of the Tongass to capture and store atmospheric carbon. In other words, what is being proposed does the opposite of restoring science to its rightful place and directly contradicts President Obama's executive order issued last month mandating environmentally friendlier federal buildings.

For the reasons cited here, the Tongass Conservation Society disagrees with The Nature Conservancy and the Sitka Conservation Society in their support of the biomass heat project being planned by the Coast Guard and discourages its implementation. It would be a waste of resources to conduct a "proof of concept" project when a review of the science currently available strongly indicates that failure is inevitable. The effort also would preclude or delay the use of energy sources that are in fact clean, renewable and carbon neutral.

• Carol Cairnes is president is Tongass Conservation Society. Write to her at P. O. Box 23377, Ketchikan, AK, 99901.

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