Fuels to Schools Heats and Warms a Community

Wood Energy March 12, 2010 Print Friendly and PDF

Council is the county seat of Adams County, Idaho, and roughly a two-hour drive north of Boise. Situated in the Weiser River valley, it is surrounded by national forests and has a population of about 800. A major employer in town, a Boise Cascade sawmill, closed its doors more than ten years ago and the area since has found itself economically depressed. Nearly 60 percent of the students in the schools are either on free or reduced-cost lunch; unemployment is one of the highest in the state at 14 percent. The school system has virtually no room for major expenditures with such a little tax base.

In 2002, after many years of high heating costs, the superintendent of Idaho’s Council School District, Murray Dalgleish, faced a difficult situation. The district’s nearly fifty-year old diesel oil boiler and radiant electric heating system that serviced four buildings needed to be replaced. Due to the archaic nature of the equipment and the currently high costs of fuel, some monthly bills were as high as $10,000 to heat space used by approximately 300 students and teachers.

School administrators looked at a number of solutions, one of which was replacing the existing boiler with a modern biomass-fired boiler. While researching alternatives, administrators discovered a grant opportunity through the U.S. Department of Agriculture’s Forest Service called “Fuels for Schools and Beyond Program.” This innovative program assists public schools and other public facilities reduce heating costs while helping improve forest health by partnering with area national forests. The program began after severe wildfires in the summer of 2000 led a resident in the Bitterroots area of Montana to find ways to link economic development to fuels-reduction practices, thus reducing wildfire risk. After discovering a case in Vermont where waste wood was being used to heat schools, he approached the leaders of his community in Darby, Montana. Since then, six states in the western U.S. have joined the program.

But why not replace the aging boiler with a modern diesel oil boiler? Adding a new biomass boiler with its various system components would cost more than replacing the existing boiler with a modern oil boiler. Initially, yes, replacing the existing boiler with a fuel oil-fired boiler would have been cheaper. However, with the cost of fuel oil increasing, it would not take long before operating costs exceeded that of a biomass-fired boiler. Biomass supply in the form of wood is not a problem for Council; it is surrounded by the Payette National Forest, which is comprised of more than 2.3 million acres of forestland; with fuels reduction practices alone, there was plenty of wood fuel in the immediate area. Also, the financial incentive provided through the Fuels for Schools and Beyond Program required a wood-fired heating system.

After lengthy discussions, school officials decided to apply for the Fuels for Schools grant. Forest Service officials sent out an engineering team to evaluate the school facilities in Council and determine suitability as a part of the grant awards process. In 2003, the Council school district was awarded Idaho’s first Fuels for Schools grant. Siemens ESCO, the Council school district’s performance contractor drafted an estimate of $2.86 million to design and install a new woody biomass heating and cooling system. The Forest Service grant provided $510,000, representing less than 15 percent of the total costs. The ventilation ducts, lighting, wiring, and piping all had to be replaced. Further, the recent introduction of summer school classes required that there be some type of air conditioning capability. The school’s facilities called for a complete retrofit, requiring work in every classroom. The system, although expensive, when completed would be the first of its kind in Idaho and cutting edge in regards to energy conservation.

In April 2004, the district asked the community to vote on a $2.2 million public bond called a Qualified Zone Academy Bond (QZAB) to help pay for the new system. This is a federally backed, special zero percent interest bond for low-income rural districts to finance building renovations. The remaining $660,000 needed would need to come from the district, $510,000 of which would be provided via Fuels for Schools. With concerns about increasing the tax burden for an already impoverished community, the bond failed by 10 votes. At this point, it became clear, outreach was essential. School officials worked to inform the public about the situation. By hosting public meetings and visiting with individuals and select groups, school representatives presented the long-term cost savings a woody biomass-powered heating and cooling system would provide. The following November, the bond received more than 74 percent of the vote.

The energy costs savings for using wood fuel in place of fuel oil was estimated at $1 million over the length of the bond; the savings would be used to pay the bond down. To back their energy conservation estimates, Siemens ESCO guaranteed the $1 million energy savings quote with a performance contract. (A performance contract is an agreement that specifies the end results desired rather than the means to reaching said results.) The new woody biomass heating and cooling system became operational in September 2005. The design focused on system efficiency, employing heat pumps to heat water to 86 degrees Fahrenheit instead of the 175 degrees Fahrenheit typically required for conventional boilers. This practice extends the life of the system and allows it to function on half the wood fuel found in other Fuels for Schools related systems. The system requires only about 350 tons of wood fuel a year for heating. In comparison, a private lumber company located just North of Council uses this same amount of wood fuel to fire its boilers for one day. In addition, there is a propane-fired boiler back-up system to ensure heat if the main biomass boiler is out of service, and when the school is in its summer session, an evaporative cooling system uses the heat pumps to circulate air-chilled water through the cooling vents.

With hopes of preparing students for potential careers, the school district also applied for and received a grant from the Resource Advisory Committee for Southwest Idaho to build a 2,000 square-foot greenhouse that would be heated by the new system. The greenhouse, when complete, would house growing native plants for the Payette National Forest (NF) thus allowing students to collect, germinate, grow, and plant native species on school grounds. The biomass project made the greenhouse project viable, as the new heating system provided inexpensive heat to the greenhouse.

The greenhouse along with participation in the operation of the boiler added an academic element for students in the areas of new technology and natural resources development. As a pilot program, the schools see many visitors interested in the system. Selected students are trained to give tours, explain the science behind it, and describe the overall operation. Students are also involved in monitoring the fuel moisture content, British Thermal Units (Btu) output from differing woods, and emissions testing.

Operation of the biomass boiler is fully automated and can be controlled remotely via the Internet. Motion sensors control lighting and heating in each classroom. The sensors recognize when the rooms are empty and after 8 minutes lights automatically turn off and the temperature in the room returns to a preset energy efficient level. Although the system is self-correcting and requires very little maintenance, it does require 24-hour a day, 7 days a week monitoring. The school employs a full-time, on-call operator, and there is an incident command procedure for backup in case the operator is absent. Maintenance of the systems includes procedures for dealing with waste and keeping the equipment clean. One ton of the woody biomass burned produces about a gallon of ash. The amount of ash depends on the type of woody biomass used. Typically the supply comes from the Payette NF and is made up of several tree species including larch, ponderosa pine, Douglas-fir, Englemann spruce, and other western species.

The boiler is cleaned several times a week; the ash is used to fertilize the school grounds and football field. Slag, the accumulated glass-like by product that results from burning wood, contains silica but is not of sufficient quantity to be a marketable product and is discarded as garbage. In larger biomass boiler operations where it is economically feasible, slag can be refined to produce glass aggregates for asphalt paving, shingle granules, and ceramic tile. Though there have been many challenges, the community of Council considers the project a success. Annually, the biomass system saves the school district around $50,000 in energy expenses. It also provides student, teachers, community members, and visitors an invaluable learning experience.

Author Kiley Barnes, Southern Regional Extension Forestry, Athens, GA.

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There are many factors that help determine the use woody biomass for energy production.  Below we consider the decision-making points involved in the process.  

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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.