Biomass Heating Plant
This year marks the 30th anniversary of Longwood's use of biomass (sawdust) to produce steam for providing heat and hot water to campus buildings. Longwood is the only public institution of higher education in Virginia and one of only two state agencies that burns biomass for heating fuel.
Longwood University completed construction of an 11,420 sq. ft. replacement heating plant in 2011. The $14 million facility located on campus contains two biomass boilers (one new boiler and one relocated boiler from the original heating plant). The new heating plant was designed to contain three boilers but due to escalating costs, the design was modified to include the installation of only two boilers and reserved space for additional boiler capacity. The two wood-fired boilers currently provide approximately 80% of the campus’ heat and hot water. Number two oil provides the additional 20% of the campus’ steam demand.
The new facility also includes two sawdust storage silos, sawdust handling system, pollution control devices, auxiliary equipment, administrative space, and space for additional boiler capacity. Sawdust is stored in two silos with a combined capacity of 18,500 cu. ft. approximately one week’s worth of fuel. Sawdust is loaded into the top of the silos by way of a bucket elevator; augers at the bottom of the silos distribute the fuel using a first-in, first-out method to each boiler minimizing fuel degradation and ensuring consistent moisture content. Augers and pneumatic tubing at the base of the silos transport sawdust from the silos to the metering bins of each boiler. Pneumatic tubing then feeds the sawdust into the boilers.
Biomass Processing Facility
In addition to the biomass heating plant, the University is constructing a biomass processing facility to provide adequate storage space for sawdust and expand its wood fuel stream. This facility, located 11 miles from campus, consists of 17.68 acres. Once site preparation is complete, the facility will include a truck tipper, truck scales, and space to stockpile sawdust. Future plans include purchasing additional equipment, such as a chipper, to manipulate wood waste from sawmills, logging and tree trimming operations, land clearing, weather-related disasters, and municipalities. Once the wood is processed, the wood fuel will be stored at the processing facility until it is transported to the new heating plant.
- Test firing of new boiler occurred in July 2010
- Campus uses 10,000-35,000 lbs. of steam/hour
- Each boiler produces a maximum of 20,000 lbs. of steam/hour
- Purchase sawdust from several local sawmills
- Permitted to burn 34,000 tons of sawdust/year
- Utilize 20-40 tons of sawdust/day (approx. 1-2 truckloads)
- Each silo is 48 ft. in height and has a capacity of 18,500 cu. ft.
- Produces approximately 700 lbs. of ash/week
More information about the biomass heating plant:
- Longwood University Biomass Heating Plant (QA Graphics, YouTube video)
- Longwood University: Dusting up power from sawmill scraps. (CBSNews.com, July 24, 2013)
- Warming a Campus With Wood: Longwood University is recognized for a three-decade commitment to biomass. (College Planning & Management, April 2013)