BY TUX TURKEL

MaineToday Media, Inc.

Maine's air quality could worsen if thousands of homeowners switch from oil heat to wood pellet stoves, according to a study done for the state's oil dealers.

The study concludes that while pellet stoves are much cleaner than older wood stoves, they generate more particle pollution and air toxics than oil furnaces.

The findings are among the first to challenge a widely-held perception that pellet stoves burn so cleanly that they don't contribute to air pollution. But with the demand for pellet stoves so great now that dealers are taking orders for next year, the cumulative impact of pellet heat in Maine could receive greater scrutiny.

Done for the Maine Oil Dealers Association, the study takes aim at a draft recommendation of the Governor's Wood-to-Energy Task Force. The task force has suggested that 10 percent of Maine homes and small businesses could be heated with wood pellets. That conversion, the task force has said, could help the state reduce its heavy dependence on costly oil heat and move toward cleaner-burning wood fuels.

Oil dealers, however, dispute what they see as an underlying message that wood heat is clean and oil heat is dirty. They've been circulating the study ahead of a task force meeting today, at which air quality issues are expected to be discussed.

"Advocating wood energy is fine, but you can't tell untruths about oil," said Jamie Py, executive director of the oil dealers trade group.

Py's approach isn't appreciated by Les Otten, the task force chairman. The oil heat industry declined to participate in his group's deliberations, Otten said, and now is using selective information to mislead people about the benefits of wood.

"They're trying to protect their turf, protect their pocketbook, so people will continue to burn oil," he said.

Comparing the air quality impact of oil and wood burning is complicated, experts say. Details matters, especially the age and efficiency of the heating equipment. Many of these variables are unknown in Maine, they say, and the choices people are making to cope with today's energy price crisis may be beyond the influence of policy makers.

The study was conducted by David Dixon of Dirigo Environmental Consultants. Dixon is a former air bureau manager at the Maine Department of Environmental Protection.

Dixon compared emissions from existing oil furnaces, older wood stoves and modern pellet stoves. The data is rough, Dixon said, and doesn't capture technological advances in both oil furnaces and wood stoves. It also doesn't include central heating pellet boilers, which are considered cleaner burning than most other wood units, or the latest generation of outdoor wood boilers.

One conclusion of Dixon's report is that pellet stoves emit 10 times less particulate pollution than older wood stoves. However, pellet stoves still release 50 times more particles than oil furnaces.

Dixon found similar patterns for carbon monoxide. Pellet stoves also compared poorly to oil furnaces in terms of air toxics, such as certain organic compounds.

Maine has good overall air quality and can handle more wood heat, Dixon said. But because pellet heat is new and fast growing, he said, policy makers should examine the potential impact.

"If we're converting older wood stoves to pellet stoves, I'd go with that," Dixon said. "But oil furnaces to pellet stoves, that's a step backwards."

These are unfair assumptions, according to Otten. The more likely trend is for people to convert from oil furnaces to central heating pellet systems, he said. Otten's opinion reflects his business aspirations. He recently started a company, Maine Energy Systems, that's marketing a high-efficiency, European pellet boiler. Some critics say Otten's financial links to the pellet industry create a bias on the task force, a charge he dismisses.

Business aside, the task force has been circulating a chart, using American and Swedish statistics, that compares pounds of particulate per heat output. The chart shows that both pellet boilers and oil furnaces have very low emissions. Pellet stoves are somewhat higher. They are trailed by newer wood stoves, certified by the Environmental Protection Agency.

Older wood stoves are nearly four times as dirty as newer ones, the data show. On the dirtiest end of the spectrum are fireplaces; gas furnaces are the cleanest. Dixon said he basically agrees with this ranking.

The chart doesn't rank outdoor wood boilers, which have had a bad reputation for belching smoke. These units are now subject to strict emission rules, however, and the cleanest ones are said to rival pellet boilers.

It's wrong, Otten said, to compare pellet stoves with oil furnaces. People who buy pellet stoves typically are replacing older wood stoves, in his view. Either way, he added, any EPA-certified wood heat is better for the environment than oil heat, because it contributes less of the carbon dioxide associated with climate change.

"The oil dealers want to talk about some pollution, but not other forms," he said.

Py said his trade group isn't taking a position on the task force's draft goal of converting 10 percent of Maine homes to modern wood heat. But if the task force doesn't address the air quality impact in its final report, Py said, he'll raise the issue at any subsequent public hearings.

Some of the state's air quality advocates say more discussion would be good.

The lack of hard data on wood burning should lead the state to go slow on any policies that encourage it, according to Nick Bennett, staff scientist at the Natural Resources Council of Maine. Mainers are switching to wood heat to save money without any government help, Bennett said. The task force should do more to explore air quality impact, he said, rather than setting goals that will likely be reached anyway through market forces.

The rush to wood is understandable when Mainers are suffering from record high oil prices, said Edward Miller, executive director of the American Lung Association of Maine. Miller, a member of the task force, said he sees any decline in air quality as a short-term trade off that hopefully will move the state toward cleaner renewable energy sources, such as wind and solar.

"This is not the solution, but it's a step in the right direction," Miller said.