Fuels for Schools: Western Montana
Experiences with converting school heating systems from fossil-fuel to wood energy has so far been successful - but almost all projects have been in the Northeast. One new wood system was recently installed in the Darby Schools in western Montana. BERC was project manager for that project, working with the Fuels for Schools program of the USDA Forest Service and with Bitter Root RC&D, the Forest Service's regional partner for the program.
BERC recently revisited western Montana, to help assess the potential in several communities for converting public schools to wood fuel.
Types of Projects that Can Succeed
Community schools that can convert cost-effectively to wood heat in the rural West, BERC found, tend to be those where:
- A new school is being constructed, or there is significant addition, renovation, or other capital project.
- Current heating fuel cost is above $50,000 per year, or when heating fuel costs are above these levels:
- fuel oil: $1.05/gallon
- LP gas: $0.75/gallon
- natural gas: $8/decatherm
- electric heat: $0.10/KWH
- The school building uses fossil fuels at these or higher levels:
- oil: above 0.5 gal/sq. ft.
- LP gas: above 0.7 gal/sq.ft.
- Natural gas: above 0.6 decatherm/sq. ft.
- The wood system is a "plug in," requiring little or no construction or heating system renovation work.
- The wood system project could be combined with a major heating-system replacement that must be done anyway.
Project Cost Considerations
The biggest lesson learned by the Fuels for Schools program so far in Montana is that the economics of heating schools with wood are more difficult in the West than in the rural Northeast. There are several reasons why:
- Rural western schools are smaller, and so have lower heating costs - fewer dollars to save.
- Wood system costs do not vary much with size. Small-school systems sometimes cost about as much as larger systems, but can save less in fuel costs.
- Montana has no program of state construction aid for schools.
- To use a wood system, many schools would require expensive retrofit or modernization work: steam-to-hot-water conversion, repairs to piping, installation of buried pipe, etc.
Schools where wood heat conversion is not likely to be economic are those where:
- Current heating costs are low;
- An expensive retrofit would be necessary for a wood system;
- Conventional fuel prices are low; and/or
- Buildings are efficient and have a low per-square-foot consumption of heating fuel.
Summaries of School Assessments
1. Polson High School
School is electric-heated. Annual total electric bill is about $110,000. But wood system would address only heat and hot water parts of electric bill: about $65,000.
Anticipated annual savings: about 75% of this, or $49,000. Estimated costs of conversion: $225,000 for wood system plus $200,000 in building costs. Total estimated cost $425,000.
Problem: project would also need significant, added expense of converting school to hot-water system for distributing heat. School could support about $150,000 of this and still have good cash flow (assuming a 20-year bond for about $575,000). More would require subsidy from Fuels for Schools, or other incentive to enable school district to maintain positive cash flow through project.
Adjacent junior high school already has hot water heating system from single boiler room. Wood conversion would be simple "plug in." School uses LP gas for heat, second most expensive fuel after oil. Wood system should reduce this bill by about 65%.
2. Thompson Falls
Very good candidate for wood heat: campus of four older buildings, already heated from single boiler house using steam distribution. Oil use high: about .63 gallons/sq. ft. Oil bill is about $43,000 per year; wood system should save about $28,000. If wood system cost about $350,000, project would be cost-effective without subsidy.
Another approach: build semi-automated wood system, for under $250,000. No subsidy needed.
3. Troy
Campus has old junior high with oil-fired steam boiler plant, and senior high with its own oil-fired steam boiler plant. Visit focused on technical viability of installing single, wood-fired steam heating plant for junior high, senior high, and electric-heated shop building. Economic viability will depend on cost of oil for both schools, and cost of electric heat, plus costs of retrofitting electric heat system and running distribution piping from new plant to both existing boiler rooms.
At smaller local elementary school, semi-automated wood system could cut combined oil/electric heating fuel bill by 65%.
4. Libby High School
Building heated by steam boiler plant. School is large, but quite efficient at retaining heat. Savings from converting to wood from fuel oil would be limited.