State regulators say they've begun to review the wood boiler regulations, with an eye to selectively easing the restrictions.
"We want to be careful,'' said Angelo Bianca, deputy director of the agency's air management division. Much of Maryland still has a problem with air pollution, he said, adding, "We want to make sure we're not opening the floodgates."
While some environmentalists are fully behind expanded reliance on wood-burning for heat, others say that newer stoves and boilers still generate potentially harmful air pollution, especially particulates that can aggravate asthma and cause serious long-term health problems.
They also worry that expanding government incentives for wood heat may slow development of other energy sources they think are much greener, such as solar. And since burning anything to produce energy also puts carbon into the atmosphere, they doubt that promoting wood heat truly helps combat climate change.
"Quite a few questions remain," said Greg Smith of Community Research, a Montgomery County group that focuses in part on environmental issues.
Wood already is the fastest-growing residential heating fuel in the state, proponents say, with consumption increasing by a third in the decade since 2000. More than 190,000 Maryland homes have wood stoves, and another 13,000 have "pellet" stoves, which burn fuel made from compacted sawdust and wood scraps.
But there's room for growth, advocates say. While the costs of heating with wood can't compete with natural gas, they see potential in the more than 800,000 homes in the state that depend on electricity for warmth and the 240,000 residences that use heating oil.
Prompted by Mizeur's legislation, the state energy agency earmarked $50,000 toward giving rebates to homeowners for new wood or pellet stoves — enough for perhaps 100 grants. Wood advocates say it's a small boost, compared to the grants and tax breaks offered for solar energy installations.
"This is for rural people, low-income people, not just the Montgomery County folks who are putting solar panels on their homes," said John Ackerly, head of the Alliance for Green Heat, a nonprofit group in Takoma Park.
Proponents also want to encourage businesses and institutions to switch to wood. In what the state energy agency calls a "game-changer grant," it's helping Catoctin Mountain Growers in Detour spend an estimated $3 million to install a "biomass" boiler. It will replace the oil- and propane-fired heating system the nursery now uses for 14 acres of greenhouses where it raises poinsettias, pansies, mums and a variety of other plants.
Richardson's wood-heated chicken house is another pilot project, underwritten and overseen by the University of Maryland Eastern Shore.
With an estimated 5,100 chicken houses on Delmarva, wood energy proponents see great potential if growers and poultry companies there can see similar benefits.
"My job is to find out whether it's grower-friendly to work with and whether it keeps the house warm enough," said Richardson, who raises chickens for Salisbury-based Perdue.
Instead of propane-fired heaters blowing warm air inside the house, a large stove that burns wood pellets has been placed outside, with heated air blown into the house through new ductwork. The stove was donated by an Alabama company hoping to make some sales in Maryland, and the university extension service is paying to have wood pellets shipped to Richardson's farm from a supplier in Pennsylvania.
Richardson is taking a wait-and-see attitude.
"I still have my gas in there," he said. "If it doesn't do the job, I've got backup."