School's new bio-heat boiler funded by Colorado Governor’s Energy Office

This old coal boiler was one of the last in operation in a Colorado school district.  The new heating system includes a wood chip boiler and geothermal heat pumps. (Photo by McKinstry)

Proving that there is more than one way to efficiently heat and cool a facility, South Routt School District in northern Colorado is replacing its old coal-fired boiler with geothermal heat pumps, a woody biomass boiler and a back-up propane furnace.

The new heating systems are part of a $4.1 million energy makeover of the district's schools and buildings. The need to get rid of the 35-year-old, failing boiler drove the project, but it expanded to include lighting upgrades, installing system controls and Vending Misers and replacing pump valves.

The school district looks forward to reduced operating expenses, thanks to the package of energy-efficiency measures. Just using wood pellets from nearby plants for fuel instead of propane will save county taxpayers about $10,000 annually. "For almost any building with 15,000 to 20,000 square feet, woody biomass is an economical alternative to propane," said Stacey Simms of the Colorado (GEO) Governor's Energy Office. Simms manages GEO's Community Woody Biomass for Thermal Usage program, which funded the installation of the new boiler. "The system can yield a return on investment in as little as three years."

Program looks for community support

The GEO established the woody biomass program in 2007 to support communities in choosing bio-heating systems for municipal facilities. The initial capital costs of the system can be a barrier, even when a local supply of biomass is available. The program is intended to provide the final push of financial support the project may need to get off the ground. "The GEO doesn't go it alone," Simms explained. "We like projects that benefit more than one facility and that leverage other funding in the community."

The South Routt School District project fits that description. Voters approved a $1.57 million bond issue in November 2007 to improve energy efficiency in the high school, middle school and elementary school and administration buildings. The bond matched funding from the state departments of Education and Local Affairs. "The South Routt school board was very proactive in gaining community support," recalled Leslie LaRocque, business development manager for the McKinstry Company. "And the community was very supportive of a clean energy solution."

The Seattle-based engineering firm, a pre-approved GEO contractor, became involved in the South Routt project while working on a performance contract for the nearby Hayden, Colo., school district. "The Hayden school superintendent knew that South Routt was going to have to replace its boiler, and suggested we call them," LaRocque said.

An energy audit that the GEO had already done at South Routt determined that replacing the coal boiler would not generate enough savings to qualify for a performance contract, even with the other efficiency upgrades. "Coal is such a cheap fuel that any other system is probably going to cost more to heat," LaRocque observed. "Fortunately, the school district raised enough funding that we could approach the project as a standard construction contract."

The audit also indicated that bio-heating would not be cost-effective for the entire complex, and it wouldn't provide cooling. McKinstry analyzed the school district's needs and recommended installing geothermal heat pumps. But even the most efficient heating and cooling system won't work in every building. The middle school's turn-of-the-century steam-pipe system could not be converted to ground-source heat pump (GHP). "McKinstry frequently installs GHP systems, but we'll look at any current technology to find the best system for the application," LaRocque said.

Woody biomass beats other fuels

The biomass boiler was back on the table, along with several other options—including a new coal boiler. But coal technology—and safety regulations—have changed since the 1970s. Coal boilers are now manufactured primarily for much larger facilities than the middle school building, LaRocque discovered. "A small boiler would be a specialty system, which would add to the cost," she said.

Air quality issues added more complications. Even if the installation received a permit—not guaranteed, in LaRocque's view—a separate building would have been required to house the boiler. "When all those things were factored in, the overall cost of a coal system became comparable to other, cleaner technologies," she said.

The wood pellet boiler was certainly cleaner than coal, and it could use the school's existing infrastructure for storing and delivering fuel. Initially scrapped for district-wide use, bio-heating turned out to be the best alternative for South Routt's middle school.

Simms noted that it is not uncommon for communities to apply for one GEO program and then find  a solution from a different GEO program. "If one specific technology isn't an option, we'll keep talking—maybe weatherization or demand-side management is what they need," she said. "Once we have that contact, we like to turn it into a success story." 

McKinstry sized the biomass boiler to heat the entire school, but also installed a propane back-up system. Propane is the most common heating fuel in parts of Colorado not served by natural gas, and it is the system McKinstry used for cost comparisons. Although a propane boiler would have cost less initially, long-term fuel costs made the wood boiler a better investment.

The biomass boiler, the last piece of the school district's energy makeover, will be delivered in September. The lighting upgrade was completed last spring, and the ground loops for the heat pump were laid during the summer. Yampa Valley Electric Association, which serves the South Routt administration buildings, worked with McKinstry to upgrade the buildings' single-phase line to a three-phase line to accommodate the GHPs. The new electric heating system will boost the cooperative's electricity sales to the school district. 

Energy programs for Colorado

Simms would like to see more Colorado utilities use the GEO as a resource for incorporating biomass systems. The woody biomass program focuses on commercial bio-heating projects, rather than power production, but helping customers reduce operating costs is always a good relationship builder. "I meet with many communities to discuss the  woody biomass program, and the interest in the New Energy Economy is definitely there," she stated.

The GEO resources to help commercial buildings and schools improve energy efficiency include performance contracting, high-performance building design and renewable energy opportunities like the woody biomass program. Residential customers can find information about home efficiency, incentives and rebates, utility bill assistance and free energy services.

The GEO's programs are not for end users only, though—the utility program provides a resource to help power providers implement the Governor's Climate Action Plan and the New Energy Economy goals at the utility scale. The program focuses on increasing utilities' use of demand-side management and renewable generation, and on building new transmission to meet Colorado's growing demand for electricity. 

Colorado utilities and their customers can visit the GEO Web site to learn more about partnership opportunities, and to download program applications.

Resources

South Routt School District

Colorado Governor's Energy Office

Community Woody Biomass for Thermal Usage program

Colorado Department of Education

Colorado Department of Local Affairs.

McKinstry Company

GEO performance contracting program

Yampa Valley Electric Association

GEO utility program

Colorado's New Energy Economy

GEO partnership opportunities

People

Stacey Simms

Leslie LaRocque

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