Craig sees savings with biomass
Southeast community first to try wood-fired energy at municipal level
An 18-month-old biomass plant in Craig is saving the city money on its heating bills, but the transition hasn't been without complications, according to City Manager Jon Bolling.
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The plant in the small town on Prince of Wales Island is the only one operating in Southeast Alaska. It burns wood chips from a nearby sawmill to heat water that is piped through three municipal buildings previously heated with oil or propane.
While Craig cut its energy bill by $40,000 last year to heat its municipal pool, savings have not stretched to help the school district's bottom line. An elementary school and middle school also are hooked up to the wood-fired heating system.
The city faces challenges running the biomass plant to optimal capacity, Bolling said. While they've worked out kinks over the past year and a half, high water content in the fuel source - wood chips bought from a local mill - still causes inefficiencies.
But savings last year of more than 50 percent to heat the expensive aquatic center make Bolling feel optimistic about the decision to switch to biomass.
"I am pleased," Bolling said of the project, somewhat of an experiment since it's the first in Southeast. "I think in the long run this will be really good for Craig."
The city is on track to recoup its $500,000 investment in 12 years. The project actually cost $1.5 million but two-thirds was funded by grants.
The year before installing the biomass plant, the city spent $110,000 on propane to heat the aquatic center - a 15,000-square-foot building with three pools where the air temperature must be kept above water temperatures to prevent evaporation.
The biomass project came about because the city wanted to get away from propane. They considered oil but a 2005 trip to Montana by Bolling and his staff convinced them biomass was a better choice. They decided to include two nearby schools.
Last year, the city paid about $20,000 to Viking Lumber for 780 tons of wood chips. The mill transports the chips to the city's plant, located among the municipal buildings it heats. The wood source in Southeast presents a challenge because the region is so wet, Bolling said.
Maintenance staff in Craig designed a drying system to blow heated air into the stockpile and remove moisture before the wood is burned. The drying takes a significant portion of energy the system creates, making the system less efficient.
As a result the two schools are not benefiting as much as the city hoped, Bolling said. He could not say how much of the energy generated is used to dry the wood.
"It's a significant enough volume that it's made a difference," he said.
Adjustments to the boiler system, working with fuel supplier Viking Lumber and special staff training helped increase efficiency somewhat and caused Bolling to predict more savings for the schools this year.
The city still uses propane to heat the pool in the summer and when it's very cold in the winter, and oil is still burned at the schools. But the amounts are less, and Bolling said the city has a smaller carbon footprint.
He said the learning process is worth it.
"For every day the cost of oil is $75 a barrel we're that much better off," he said.
• Contact reporter Kim Marquis at 523-2279 or kim.marquis@juneauempire.com.