Managing the Resource: Another Crack at Local Energy
Paul Kando
Camouflage hides it from view on Google Earth. Even seen from campus across a state road, the undulating roof line of this low profile building suggests any number of possible functions: a museum? Classrooms? Laboratories? In fact, this is the Biomass Power Plant the visitor journeyed here to see. It heats the entire campus of Hotchkiss High School in Lakeville, CT, a campus housing 600 boarders in 85 buildings that total 1.2 million square feet. The fuel is locally sourced wood chips designated a carbon neutral fuel by the International Panel on Climate Change. They replace 150,000 gallons of fuel oil per year, cutting the school’s heating bill in half.
photo credit: Centerbrook Architects and Planners
The campus district heating system circulates 180º water to all buildings. The combustion temperature of the boiler is 2000ºF while the stack temperature is only 340º – a good indicator of the system’s high efficiently. Two stage combustion ensures a near-complete burn. Sulfur dioxide emissions have been cut by 90% and the carbon monoxide content measured at the stack is under 100 parts per million. What remains is mostly water vapor. Ash from the plant is used as fertilizer around this campus, which plans to become carbon-neutral by 2020.
The wood chips come from Forest Stewardship Council (FSC) certified forests. FSC promotes environmentally, socially and economically sound management of the world's forests. FSC-certified forests comply with all applicable laws of the country in which they are located, including international treaties and agreements to which the country is a signatory. Long-term tenure and use rights to the land and forest resource are clearly defined, documented and legally established. Forest operations recognize and respect the rights of indigenous peoples to own, use and manage their lands and resources.
Forest management encourages efficient use of the forests’ multiple products and services, conserving biological diversity and its associated values, water resources, soils, unique and fragile ecosystems and landscapes . It maintains the ecological functions and integrity of the forest, ensuring economic viability and a wide range of environmental and social benefits, including the long-term social and economic well being of forest workers and local communities.
FSC forests operate on the basis of a written management plan in which long-term objectives and the means of achieving them, are clearly stated. Ongoing monitoring assesses the condition of the forest, yields of forest products, chains of custody, management activities, and their social and environmental impacts. Management decisions are guided by a precautionary approach.
FSC plantations are planned and managed in accord with the same principles. While they can provide an array of social and economic benefits and help satisfy the world’s needs for forest products, plantations don’t replace natural forests. Instead they complement natural forests, reducing pressures on them and promoting their restoration and conservation.
Who says that a heating plant must be out of sight in some underground hole? The Hotchkiss plant sits at the bottom of a gentle slope between marshes and a golf course, blending harmoniously with the landscape. It hides its industrial character under a green roof, which collects and filters rainwater. And it doubles as a 16,500-square-foot living class room. Designed by Centerbrook Architects, it exposes ecology-friendly technologies and sustainable construction materials to students and visitors alike. A mezzanine walkway overlooks the boiler room. Here an informal exhibit of explanatory charts, maps, and several interactive computer terminals track the plant's performance.
The exhibit also highlights locally abundant wood products and renewable building materials used throughout the building for framing, trusses, railings, veneer, and wood composite boards. FSC certified wood or indigenous timber was used whenever feasible. For example, the railings were locally harvested, milled, kiln-dried, and fabricated. The trusses are glue-laminated, optimizing the structural values of this renewable resource. Glulam trusses have less embodied energy than either reinforced concrete or steel, yet they can be used for much longer spans, heavier loads, and more complex shapes.
Other indoor features include water-conserving plumbing fixtures, the use of high recycled content local materials, abundant daylight, and highly efficient mechanical systems and lighting. Outdoors, the visitor may follow a nature trail with views of the green roof, which absorbs and filters rainwater runoff. There is also a rain garden. There are bioswales, and nearby wetlands.
To this visitor two things are obvious: First, utilizing local energy is a better economic deal than laying gas pipelines. After all, hot water pipes are cheaper and safer and, no matter how cheap the gas, after the cost of one time improvements is recovered from fuel savings, renewable energy and energy conservation are cheaper yet: they are free. Second, it helps to be educated abut all this. The Hotchkiss campus is a good place to start.