Preliminary Assessment: New Biomass Heating System, and Combined Heat and Power Plant, at Johnson (Vt.) State College

From 2003-04, the Biomass Energy Resource Center (BERC) carried out a preliminary study of the potential for converting the central district steam-heating plant at Johnson State College (JSC) in Vermont from oil to biomass fuel - including the potential that a biomass system could also generate electric power.

This study was requested by Johnson State, with approval from the Chancellor of the Vermont State College system. It was made possible by U.S. Department of Energy funds available to BERC.

Here in brief are the study's recommendations:

• BERC assumed that the college will eventually build a new central heating plant to replace its oil-fired central plant, now in the basement of the main campus residence hall. The college desires to make this change, due to fire-safety concerns in the residence hall. This move would open up the potential for a wood-chip biomass system.
• The most promising of several potential locations for a new central heating plant is close to the main campus, just east of a parking lot and Arthur Hall, site of the current heating plant. A second choice is the Maintenance Garage. Both locations would provide good access for woodchip deliveries, and could service any future development on the east end of campus.
• A new, biomass-fueled central heating system in a new facilities building could provide either steam to the campus's existing distribution system, or hot water to a new, piped hot-water system. Switching to a hot water system offers technical, efficiency, operating, and maintenance advantages - but it would involve issues of cost, along with the best means of adapting or converting existing building heat systems.
• A one-time project to convert to a new hot water distribution system would be prohitively expensive. B- but the new system could be built in stages, with buried pipes gradually extending throughout campus, and with building systems converted to hot water over time as buildings are modernized and improved. Ultimately, the existing steam system could be retired, and its boiler equipment removed or converted to produce hot water as a backup system in the new plant.
• A more complex approach would be to build an advanced, biomass-fueled combined heat and power (CHP) plant, to meet some or all of the college's electricity needs while also producing heat. A CHP plant could be based either on traditional steam generation or on new biomass gasification technology, when that becomes commercial.

On a preliminary basis, a biomass central-heating project at JSC offers clear advantages. However, as with any new biomass facility, many factors need to be considered. These include capital costs, technology, plant location, availability of wood chips, plans for building upgrades and campus expansion, biomass fuel's stabilizing effect on long-term energy costs, the need for training and/or for new trained personnel, and the impacts on the local economy and environment.

Here are the preliminary study's key factual findings and projections:

1. A new woodchip boiler, with capacity to meet all the campus's heating needs, during a "peak" winter hour, would replace about 1,450 gallons of fuel oil during peak heating season with about one ton per hour of wood chips - requiring roughly one truck delivery per day during the winter.
2. The woodchip boiler would provide heat at about half the operating costs of the current oil-fired plant. Based on 2003 energy prices, this would create annual savings of about $70,000. Converting campus buildings currently heated with electricity to biomass heat would save up to 75 percent on their heating costs.
3. A new, 750 kWe biomass CHP plant would generate waste heat in the form of steam and hot water. Additional heating capacity would be required to meet the college's total needs, and could be met by the current central heating plant, or by a new woodchip boiler.
4. Because biomass as a fuel source is neutral in terms of carbon emissions, either a new biomass central heating plant or a CHP plant would dramatically reduce JSC's carbon emissions. Historically, wood chips are also a much cheaper, more stably priced fuel - and supplying woodchip fuel from local forest-harvesting operations would positively contribute to the area's economy.
5. A campuswide district heating system, fueled with biomass, could possibly be expanded to serve nearby buildings in the town of Johnsonthe surrounding community as well.

Stages of the Study & Follow-Up

In approaching BERC for this preliminary study, JSC's main objective was to reduce its energy costs. Other potential benefits recognized by the college included significantly cutting its consumption of fossil fuel, developing an aggressive renewable energy program, creating a "carbon neutral" heating plant on campus, and contributing to local economic development.

Before requesting this study, Johnson State had already installed many energy-efficiency and other upgrades to its buildings: new roofing, windows, insulation, thermostatic controls, more efficient lighting, remodeled shower facilities, and new carpeting.

This study assumed that the college will be expanding in the future, though no official expansion plans are yet in place. Clearly, the area of campus that would permit any major building expansion is to the east of the main college buildings. The study considered the energy- and heating-related impacts of potential growth in this area.

After meeting with JSC and with the Chancellor of the state college system, BERC met with officials of the municipal power utility, and with the Vermont Public Power Authority, to explain the study's objectives. It was agreed that the municipal utility and the VPPA would receive this study's results, and that they would be invited to join in a more detailed feasibility study if the preliminary results were positive, and if a combined heat and power plant appeared feasible.

In March 2004, the Institutions Committee of the Vermont State Senate convened a hearing in the State House to discuss the potential for campuswide renewable energy at JSC. Such a project, it was noted, might be expanded to serve the surrounding community with a district heating system, possibly biomass-fueled. Participants - including BERC, JSC, VPPSA, and the municipal power authority - agreed to report back to the Institutions Committee after the preliminary study was complete, to develop support for the needed next steps.

As a result of these efforts, the Vermont Legislature in 2004 authorized $20,000 in state funds for a more detailed planning study of the potential for wood-chip heating to meet current and expected growth at JSC, and for serving nearby parts of the town of Johnson, with wood-fired district heating.