School's biomass boiler entering 'junior year'

Students start classes at Glacier High School today and tomorrow, but the school's biomass boiler has another few days left of summer vacation.

The boiler probably will start sometime next week, said Chuck Cassidy, Kalispell Public Schools' director of transportation and facilities. That's about a month earlier than it has started in its previous two years in operation. In 2007 and 2008, the district fired up the boiler in October.

"The biomass boiler can't save you money if you don't turn it on," Cassidy said.

Chilly September mornings make heat necessary at the school, and the boiler is less expensive than natural gas.

For most of the summer, Glacier High School's heat sources were turned off. The gas supply was turned back on a couple weeks ago, when sports teams began practicing and athletes needed hot showers. Food services, which also needed hot water, began operating around the same time, Cassidy said.

"Hopefully we'll bring the biomass boiler on next week," he said. "We'll try to run it throughout the year."

This year, the boiler will run primarily on wood chips, supplied by a Kalispell vendor, John Jump Trucking. For its first two years of operation, the boiler ran on hog fuel - shredded and ground wood and bark fibers. The hog fuel caused problems for the boiler during the 2007-08 school year.

The boiler's conveyance system was ill-equipped to handle the fuel, despite school officials' specifications. They had told the manufacturer, Hayden, Idaho-based Precision Energy Services, that they wanted a system that could handle all types of fuel, everything from hog fuel to pellets. While Glacier High's boiler was designed to run primarily on wood chips, the manufacturer thought it could work with hog fuel.

It did work, sometimes, but it wasn't reliable enough for the district. The boiler went through a $167,000 retrofit last fall, and its new conveyer system handled the hog fuel much better than the original.

However, according to an analysis performed by CTA Architects Engineers in June, Glacier still used much more natural gas than biofuel throughout the school year.

CTA attributed this in part to the biomass boiler not operating on weekends or holidays until January, increased student population thanks to the addition of seniors in Glacier's second year of operation, and not having boiler operators as consistently on scene as they had been the previous year, when problems with the conveyer system required constant supervision.

The biomass boiler accounted for about 32 percent of Glacier's energy consumption during the 2008-09 school year, according to CTA. It accounted for 48 percent of the school's energy consumption during 2007-08.

CTA recommended aiming for 65 percent this year. The company estimates that meeting that goal would save almost $49,000 from last year. By its 30th year of operation, the boiler could save the district more than $226,000 a year, according to the analysis.

Despite the potential savings, the district has never studied how much money it could save by installing biomass boilers at other school sites, Cassidy said.

"The only one large enough to justify it is Flathead," he said. "You have to look at the economy of scale."

Installing a boiler at Flathead High could be problematic, largely because of the logistics of supplying the fuel, Cassidy said. There is little room for a semi truck to drop off a load of fuel in Flathead's downtown location, he explained.

The wood chips that Glacier's boiler will burn this year are a little more expensive than the hog fuel it has used for the last two years. Wood chips are costing the district $57.67 a ton, compared to the $45 per ton the district paid T.B. Gray for double-grind hog fuel. In the past, chipped fuel has cost between $100 and $150 a ton, which is why the district opted not to use it in the first place.

But wood chips are a better, more energy-efficient product with fewer byproducts than hog fuel, Cassidy said.

"It conveys better, flows better," he said. "We ran some of it last year on a trial basis, and it worked fine."

The chips should produce less gas, ash and other impurities, he added, "and it should be more user-friendly for us, from a maintenance and operation viewpoint."

Right now the cost of wood chips is reasonable, but if the price should jump in the future, the district can purchase another fuel type. John Jump Trucking, which also supplies fuel for the biomass boiler that heats Eureka's public schools, offers a variety of fuel types, Cassidy said.

"We don't know that chips won't be expensive again if the economy turns around and there's a market for it," he said, adding that the ability to provide a variety of fuel types was a requirement for the companies that bid on the contract last spring.

"We would like to be able to see what they could provide across the spectrum. Jump was able to give us all of them," he said.

Reporter Kristi Albertson may be reached at 758-4438 or by e-mail at kalbertson@dailyinterlake.com