Transcript Montpelier District Energy

Montpelier District Energy
Gwendolyn Hallsmith, Director
Planning and Community Development
City of Montpelier, Vermont
History
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2001 feasibility study by CANMET for heat
Voters passed $250,000 bond in 2003
“for the City's share of the development of the District Heating
System involving the State of Vermont's central heating plant in
the state complex and the installation of hot water transmission
mains from the plant to the City of Montpelier's municipal
complex in and around City Hall.”
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Energy Town Meeting in 2007
District Energy Team formed
2007 Clean Energy Development Fund Grant
for $25,000 for CHP feasibility study
Feasibility Study Tasks
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Study the technology required for a combined heat and
power (CHP) plant to optimize power generation and
heat using sustainably harvested Vermont forest
products.
Prepare a market study and identify buyers and
projected prices of the renewable energy credits (RECs),
the capacity, and the power.
Develop a financial plan that compares the long-term
viability of a CHP as compared to the original heating
plant proposals that had been studied in the late 1990s.
Prepare an outreach plan to the end users of both the
electricity generated and the heating system to
determine what incentives will be necessary to get
committed customers of the new system.
Review of Biomass Facilities
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Duke/St. Paul District Energy facility
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European models for biomass generation
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City of Växjö, Sweden
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Grève-in-Chianti, Italy
Canadian technologies
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Prairie Biogas: Pyrolysis and Synfuels
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Organic Power Technologies
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Plasco Conversion System
Wood to Energy Alternatives
1.
Burning wood chips
2.
Burning pellets
3.
Carbonization
Low temperature, very long residence time
Liquid 30%, Char 35%, Gas 35%
4.
Pyrolysis
Moderate temperature, short residence time
Liquid 75%, Char 12%, Gas 13%
5.
Gasification
High temperature, long residence time
Liquid 5%, Char 10%, Gas 85%
St. Paul Biomass Plant
Wood Burning
District Energy Plant
St, Paul, MN
April 2000 – Waste wood combined heat and power plant that
supplies steam to District Energy of St. Paul and 25 MW of
electricity to Xcel Energy (Northern States Power)
St. Paul Biomass Plant
District Energy St. Paul
currently provides heating
service to more than 180
buildings and 300 singlefamily homes, representing
over 30.7 million square feet
of building space, or 80
percent of St. Paul’s central
business district and
adjacent areas.
Confidential and Proprietary
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St. Paul Biomass Plant
Service
Hot water district heating delivered to customers yearround for space heating, domestic hot water and
industrial process use
Provider
District Energy St. Paul Inc., an independent, non-profit
company
Distinction
It is the largest, most successful hot water district
heating system in North America
Production capacity
Combined heat and power plant, four gas/oil-fired
boilers, two coal/gas-fired boilers, backup plant and
mobile boiler: total 289 megawatts thermal (987 million
Btu per hour); also 860-kilowatt, turbine-driven
generator
Confidential and Proprietary
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Växjö, Sweden: Fossil Fuel Free Växjö
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Since 1993, the city
has reduced carbon
emissions by 30%
per capita
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Results largely due to
biomass heating –
90% comes from
renewable sources
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Recipient of 2007
Sustainable Energy
Europe Award
Grève-in-Chianti, Italy
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Waste gasification
plant
Operating since
1992
6.7 MW electrical
power
Product gas for
cement kiln
Circulating fluidized
bed gasifiers
Organic Power Technologies
Carbonization or Fast Pyrolysis System
(Variable gasification)
Moderate Temperature (600 – 800C)
Liquid 12%
Char 23%
Gas 65%
Feedstock
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Wood Chips
Wood waste
Straw
Poultry litter
Horse bedding
Plastics
System Products/Outcomes
100 Tons of Wood Per Day
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105 MWh electricity from gas
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21 tons of charcoal
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506 GJ heat
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10500 litres of bio-gas
Prairie Biogas
System Components
1. Shredder
2. Pyromex Induction Heating System
3. Syngas-burning Engine
The Process
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Pretreatment
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Pyrolysis (syngas & heat)
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Electricity Generation
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Heat Production
Feedstocks
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Wood chips
Sewage Sludge
Farm Waste
Plastic waste
Waste from leather and
fur industry
Tannery waste
Fly ash from power
plants
Paper and cardboard
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Plastic packaging
material
Used oils and
hydraulics
Tires
Medical & Hospital
waste
Natural fiber products
Shredder waste
Plastic and rubber
Plasco Conversion System
Waste to Syngas
Syngas to Electricity
Plasco Plant
One ton of waste…
1.
1400 kWh electricity
2.
55 days of household use
3.
150 kg of vitrified slag (sold as aggregate)
4.
5 kg sulphur (soil enhancement)
5.
1.3 kg heavy metals and filter screenings
6.
300 litres of potable water
7.
5 – 10 kg salt
Questions to Consider
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Is waste a renewable resource?
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Does it qualify for RECs?
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Which is more sustainable – wood or waste?
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Will using waste for fuel undermine reduction,
composting, and recycling efforts?
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How would you structure the public/private
partnerships necessary to manage this kind
of plant?