Biomass District Energy: A Roundtable
District energy uses the distribution of thermal energy from one or more central plants to multiple buildings. This replaces the need for individual, building-based boilers, furnaces, and cooling systems. District energy is now used in much of downtown Manhattan, at the Pentagon, in small cities like Cornwall, Ontario and Jamestown, New York, and in hundreds of colleges and universities around the country.
Biomass district energy uses biomass fuels - such as waste wood, low-value forest residues, or agricultural crop wastes - in place of conventional fossil fuels. Biomass district energy can make sense in areas with a readily available supply of biomass, such as the forested Northeast. Biomass district energy heats most of St. Paul, Minnesota and Charlottetown, Prince Edward Island, along with Vermont's two state office complexes and a score of college campuses in forested parts of the country.
- sharply reduces the emissions of climate-change gases;
- offers fuel pricing that is generally lower and much more stable than fossil fuels; and
- can be a powerful tool for economic development.
The Roundtable: A Chance to Learn and Clarify
Biomass district energy has drawn interest from community leaders, facility managers, utility executives, environmental activists, and forest resource professionals. But while the promise is clear, the path to implementation is largely uncharted.
In 2003, funding from the U.S. Dept. of Energy enabled the Biomass Energy Resource Center (BERC) to host a two-day Biomass District Energy Roundtable in Grand Isle, Vermont. Participants included government officials, foresters, energy researchers, environmentalists, utility executives, community activists, engineers, facility managers, and boiler plant operators from the U.S. and Canada.
After presentations on biomass district energy in Canada and St. Paul, attendees divided into five discussion groups. Each looked at a specific, Vermont-based case study in a specific project type:
- small community
- medium-sized community
- large community
- educational campus
- industrial site.
Biomass District Energy In Action
1. Canada's System
In Canada, where some 80 public and private systems are in place, district energy is closely linked with the development of community energy strategies. To its customers, district energy brings a value-added service: it provides warmth, not fuel; security of supply, not a maintenance headache; and economic benefit, not a monthly invoice.
The federal CANMET Community Energy Systems group does pre-feasibility studies on a cost-recovery basis for communities with limited fiscal resources. These studies help raise stakeholder awareness of the contribution that district energy can make to a community. CANMET also provides communities with an unbiased information resource.
2. St. Paul, Minnesota
The non-profit District Energy St. Paul system heats over 75% of the city's downtown - more than 23 million square feet of building space. It also provides chilled water to over 8 million square feet of building space, along with domestic hot water, process heat, and electricity. The plant is located downtown, and has the flexibility to use a variety of fuels: coal, natural gas, and wood waste.
District Energy St. Paul recently finished building a 25 MW combined heat and power (CHP) plant that is fueled with wood waste. This $52 million project is now the largest wood-fired district energy system in the U.S.
Vermont Case Studies
1. Small Community: Richford Energy Project
A grassroots organization of community members in this northern town is committed to implementing the Richford Wood Initiatve, a planned, combined heat and power (CHP) plant and district heating system using advanced, low-emission wood gasification technology. The project aims to use locally available, low-grade wood to fuel the plant on a sustainable basis, improving local woodlots and boosting the economy.
The preliminary plan is first to develop a small, wood-fired district heating plant downtown, in a renovated industrial building, then to build the biomass CHP system at an industrial facility just outside town. Planners envision a three- to four-year project costing $1 million to $5 million.
2. Medium-Sized Community: Montpelier Community Energy System
Montpelier's Capitol Complex of state office buildings has been heated by a central, wood-fired steam plant for about 18 years. The proposed project will expand this plant, perhaps move it, improve emissions controls, and run hot-water piping to serve municipal and commercial buildings in downtown Montpelier.
A preliminary feasibility study found the proposed system could deliver heat to downtown buildings at slightly less than current costs, with revenues from the sale of thermal energy supporting the system's financing and operating costs. In 2003, city voters passed a $250,000 bond issue that was the first capital commitment to the project.
3. Large Community: Burlington Community Energy System
Built in the mid-1980s, the McNeil Generating Station is a 50 MW, wood-fired power plant that generates electricity for the New England power grid. The plant was also designed with capacity to supply thermal energy for district heating. If such a system were built, the nearby University of Vermont (UVM) would account for half the total heat load. UVM's gas- and oil-fired central heating system serves 85% of campus buildings; connecting it to McNeil would effectively move the entire campus heat load from fossil fuels to biomass.
The most significant barrier to this project is the nearly $10 million cost of installing a mile-long steam pipe connection between McNeil and UVM. The current proposal is to connect UVM first, along with the neighboring medical center, then hook up the downtown and last the neighboring city of Winooski. A 2001 resolution by UVM's Board of Trustees supported the community energy proposal. But the university remains concerned about district energy prices and reliability - and is now considering a competing proposal for a 15 MW gas cogeneration plant, which would commit UVM to a fossil-fuel future.
4. Educational Campus: Middlebury College
Begun in 2002, Middlebury College's Carbon Reduction Initiative aims to greatly lessen the college's contribution to climate change. The project is focusing on the central heating plant, which consumes 1.7 million gallons of heavy fuel oil per year and is the campus's chief emitter of carbon dioxide.
The college is actively assessing the policy issues and technical options for establishing a biomass central heating, and perhaps also power-generating, plant on campus.
5. Industrial Site: St. Albans Commercial/Industrial Park
The manufacturing firms in the St. Albans Town Industrial Park require about 4 MW of electrical power capacity, plus a natural gas distribution infrastructure. The Franklin County Industrial Development Corporation, which owns the park, is interested in developing a cost-efficient CHP plan that would provide stable energy prices through district heating and cooling, for current and future park tenants.
Two Key Findings from the Round Table
For more biomass district energy projects to be developed, the group identified two components that are critical:
- Every successful project requires a strong advocate, supported by true stakeholders - people or groups who stand to gain, lose, or be significantly affected by the proposed system. Identifying and engaging stakeholders is key to success.
- There is a strong need for information and education about biomass district energy. The path to implementing these projects is difficult: the lack of readily available educational or technical material may derail first efforts to engage stakeholders, and impede efforts to present a convincing story.
Identifying Informational Needs
1. Educational resources.
These include:
- objective, useful information about projects, both biomass and district energy;
- working examples of biomass district energy systems;
- funding options and financial models for operating a system;
- reliable information on environmental benefits and risks; and
- information on economic benefits, both project-related and more far reaching - such as job creation, and retention of energy dollars in the community.
2. Guidance in policy development.
Because biomass district energy and community energy systems are relatively new, policies to govern these systems do not exist - and the choice to develop them are not generally promoted by the average user or local utility. To help develop consistent state and federal policies, legislative bodies and government officials need information about the main advantages and attractions of biomass district energy.
3. Financing mechanisms.
Biomass district energy systems require significant capital investments; yet there are no financing instruments designed for this kind of project. Banks and conventional funders of community infrastructure projects and energy facilities need to be educated about biomass energy, its costs and benefits.
4. Community participation.
Winning "buy-in" from a wide variety of people and organizations - including energy users, local officials, potential system owners, and financiers is vital, and depends on communication. Especially vital is scientifically supported information about biomass district energy and its benefits. Because each project has its own unique benefits, a cookie-cutter approach cannot work; this underscores the value of community energy planning, and the vital role of the pre-feasibility study.
5. Logical development path.
There is a need to develop a logical path, including readily available resources and technical assistance, to ease the process of assessing feasibility, development, and implementation.