Brattleboro Thermal Utility, Inc.
Marlboro College Technology Center, 2nd Floor
28 Vernon Street
Brattleboro, VT 05301
What is District Energy?
District energy systems produce steam, hot water, or chilled water centrally and distribute it to multiple buildings through a netwrok of buried, insulated pipes. Buildings connected to that network use this thermal energy for space heating, domestic hot water heating, or air conditioning instead of having separate heating or cooling equipment.
What is Combined Heat and Power (CHP)?
Thermal power plants producing only electricity operate at a thermal efficiency of about 30% with the remainder rejected as heat into the atmosphere. Combined Heat and Power (CHP) utilizes both the heat and the power, significantly boosting plant efficiency and reducing air emissions. District energy systems can use CHP - also called cogeneration - as a low-cost source of thermal energy.
How Might a District Energy System work in Brattleboro?
The basic district energy system proposed for Brattleboro would distribute heat produced in a biomass-fueled CHP plant. The plant would sell renewable power to the electrical grid and deliver hot water to industries, businesses, and households through an underground piping network. The plant would primarily utilize clean wood residues from sawmill opperations, in-town tree trimming, and sustainably managed forests. Additional wood fuel could be provided by short rotation energy crops grown by local farmers. The initial plant would produce about 5 to 6 megawatts (MWe) of electricity and provide 15-20 MWt of thermal energy in the form of hot water, which would provide roughly one-third of Brattleboro's electricity and heating requirements. Additional plants would be built as needed to meet heating demand.
Why Brattleboro?
With cold winters, expensive imported fuels and a relatively high percentage of low-income households, Brattleboro needs less expensive heating. With high downtown densities of residential, commercial, and industrial facilities, Brattleboro could support an efficient heat distribution network. By using clean renewable fuel from local farms and forests, Brattleboro's energy dollars would stay in the local community instead of leaving the state to pay for fuel imported from other states and countries. New local electric generation would also increase Brattleboro's electric reliability. A community-wide district energy system would also create jobs for construction and ongoing operations, and low-cost energy could be used to attract new businesses to town. The project would also firmly position Brattleboro as a national leader in the transition to sustainability.
What is Brattleboro Thermal Utility, Inc?
Brattleboro Thermal Utility, Inc. (BTU Inc.) started in 2007 as an ad hoc group of local citizens exploring the feasability of implementing a biomass-fueled CHP district energy system in Brattleboro. BTU Inc. became a registered nonprofit on March 6, 2008 with the objective of creating a community energy system for the town of Brattleboro generating both electricity and thermal energy, using biomass as a fuel for the benefit of multiple stakeholders and the town as a whole. Many of the nonprofit's board and members have businesses or homes within the downtown area and related expertise.
How can I help?
Spread the word, and please contact us if you would like to get more involved. Please let us know if you have any expertise to share. Come to a board, committee, or public meeting
Where are systems like this being used now?
District energy systems are used very widely in northern Europe. In Denmark and Sweden, for example, more than half of all homes are heated with district heating systems. There are hundreds of wood-fired CHP plants that provide heat to district energy systems in Europe. In the United States, there are about 6,000 district heating systems using old technology (including steam instead of hot water as a heat-transfer medium). Most serve university campuses, hospital complexes, military bases, and downtown areas of large cities, although a handful serve smaller communities. Wood chips are currently used fairly widely in Vermont for heating schools and a few downtown areas. For example, a wood chip boiler heats Brattleboro Union High School and Middle School, and the Windham County Career Center, but it provides heat only, not electricity. There are a small number of woodchip-fired CHP district systems across the country, ranging from Mount Wachusett Community College in Massachusetts to the City of St. Paul, Minnesota where a 25 MW wood-residue CHP plant serves the largest hot-water district energy system in North America, and one of the only examples of a technology that is now commonplace in northern Europe.
Is district energy reliable?
Most district energy systems operate at a reliability of greater than 99.9 percent and have backup systems readily available. In addition, this CHP system would be designed to operate independently of the electrical grid, providing at least some of Brattelboro's electrical needs in the event of a widespread transmission systems outage.
How hard is it to retrofit a building for district heat?
Houses and commercial buildings with hydronic (hot water) heating systems can easily be connected to the district heating system. In the case of electric baseboard heat, an entirely new heating system would need to be installed. Ideally, a process would be established to implement additional energy conservation measures at the same time, and also provide long-term financing to reduce or eliminate up-front conversion costs for building owners.
How much will the project disrupt downtown activities?
Installing the distribution piping is a major task, but much of the piping in Brattleboro can be routed along rights-of-way and alleys rather than under major thoroughfares, to minimize disruptions. Also, development could be planned to coincide with other improvements such as municipal sewer and water pipe upgrades, or installation of fiber-optic cable. This kind of coordination can improve the economics of the system as well as minimize disruptions.
How much will it cost?
A detailed financial model has not yet been developed, but initial calculations indicate that the system would reduce heating costs for participating consumers, with the amount of savings largely dependent on the number of customers who choose to participate. Connecting a majority of buildings along the pipeline route, for instance, would reduce costs for every customer. The capital cost of the plant and distribution system could be financed in a number of ways to minimize energy costs to consumers.
How will it affect the environment?
This system would greatly help efforts to reduce Brattleboro's impact on climate change, and would reduce local air pollution emissions significantly. By using sustainably grown wood-chips, the system would be 'carbon-neutral.' New biomass growing to replace the wood that is burned absorbs as much carbon as the CHP plant emits. In addition to being very efficient, the new plant would use advanced emissions controls and would generate significantly lower emissions than the many smaller fossil fuel and wood heating systems it would replace.