McNeil Generating Station
111 Intervale Road, Burlington, VT 05401 | (802) 864-7446
Table of Contents
McNeil Generating Station Q&A
The McNeil Generating Station is jointly owned by BED (operator and 50% owner), Green Mountain Power (31%) and Vermont Public Power Supply Authority (19%). There are 40 people employed at the station. Employees include a maintenance crew, equipment operators, fuel handlers, foresters and administrative and engineering support personnel. A minimum staff of four is needed to operate the station at any given time.
How much electricity is produced?
At full load, the plant generates 50 megawatts (MW) of electricity, about enough for the needs of Burlington.
How much fuel does the McNeil Station use?
At full load, approximately 76 tons of wood chips are consumed per hour (about 30 cords). When the plant is operating at full load on gas, it uses 550,000 cubic feet of gas per hour.
Does the McNeil Station use other fuel sources?
Yes. It can run on natural gas and oil. In 1989 the Burlington Electric Commission accepted a proposal from Vermont Gas Systems to supply gas to McNeil on an interruptible basis between May and November of each year. In October 1989, the capability to burn natural gas was added. While wood remains the primary fuel, the addition of gas allows McNeil to diversify its fuel options. The station can also use fuel oil or any combination of wood, gas or oil.
What about air emissions from McNeil?
McNeil is equipped with a series of air quality control devices that limit the particulate stack emissions to one-tenth the level allowed by Vermont state regulation. McNeil's emissions are one one-hundredth of the allowable federal level. The only visible emission from the plant is water vapor during the cooler months of the year. In 2008, McNeil voluntarily installed a $12 million Regenerative Selective Catalytic Reduction system, which reduced the Nitrogen Oxide emissions to 1/3 of the state requirement.
How is the wood inventory controlled?
The station has a wood procurement and storage plan. The wood chip piles at McNeil are limited in size and are monitored to ensure they do not reach the early stages of decomposition. The wood fuel is consumed on a first-in, first-out basis to control the age of the material.
Where does the wood for the McNeil Station come from?
Mostly the wood comes from within 60 miles of the station. Ninety-five percent comes from logging residue and cull material created when harvesting higher value wood products. Harvests are conducted in accordance with strict environmental standards specified by the Vermont Public Service Board.
The wood is chipped at the harvest site and delivered in trailer trucks to the plant or to a railcar loading facility in Swanton; at least 75 percent comes by rail. A small portion arrives in an unprocessed form that can be stored and chipped when needed. McNeil Station also purchases lumber-making byproducts such as bark and shavings or clean urban wood waste.
What does a wood chip harvest look like?
Most harvests are partial cuts designed to improve growing conditions for the remaining trees. When a new crop of trees needs to be created or when wildlife habitat improvement practices require it, small areas may be cleared after approval from a professional forester. McNeil also receives wood from site conversions for development or agricultural expansion. BED’s foresters monitor each harvest operation to see that wood is harvested properly. The station’s wood suppliers are required to conduct their activities in accordance with strict standards to protect the environment.
How much does wood fuel cost?
The wood cost depends on such factors as hauling distance, transportation method and the type of material. Wood hauled directly to the plant is less expensive than wood that is reloaded and shipped by rail. Current wood costs range between $22.00 and $33.00 per ton delivered by truck. Rail transport and extra handling adds about $7.00 per ton.
Where does McNeil's water come from?
There are four wells located approximately 4,000 feet north of the station. The output of any one well is enough to replace water losses at the plant. Most water losses occur in the cooling tower by evaporation.
What happens to "waste" water?
Water removed from the McNeil Station is monitored for pH, temperature, flow and metals. It is treated to maintain a balanced pH, allowed to cool to a temperature that will not adversely affect aquatic life and then pumped to the Winooski River (located about 1,000 feet east of the plant). Except for dissolved mineral salts, the regulated discharge of waste water going to the Winooski River is comparable in quality to the water drawn from station wells.
What is done with the ashes?
Wood ash, the end-product of burning wood fuel, is temporarily placed on site in a landing area. BED works with a private contractor who transports the ash and markets it as a soil conditioner for pH control and a source of potash and potassium. McNeil ash is approved as a soil conditioner for organic crops. The heavier portion of the ash (bottom ash) is used as a base for building roads or an additive for manufactured topsoil.
McNeil Station & Equipment Facts
|Generator gross output||55 megawatts|
|Net station electrical production||50 megawatts|
|Generator voltage||13,800 volts|
|Turbine/generator speed||3,600 revolutions per minute|
|Steam pressure at the turbine throttle||1,275 pounds per square inch|
|Steam temperature||950° Fahrenheit|
|Steam flow||500,000 pounds per hour|
|Fuel consumption (wood)||76 tons per hour|
|Fuel consumption (gas)||550,000 cubic feet per hour|
|Cooling water flow||42,000 gallons per minute|
|Electrostatic precipitator voltage||30,000 volts DC|
|Air temperature on the top floor||110° Fahrenheit|
|Stack height||257 feet|
|Building height||132 feet|
|Boiler firebox height||80 feet|
|Heaviest boiler section, upper drum||72 tons|
|Weight of turbine/generator||183 tons|
|Largest electric motor, induced draft fan||2,500 horsepower|
|Number of electric motors||320 motors (approx.)|
|Number of condenser tubes||5,362 tubes|
|Cooling tower basin capacity||500,000 gallons|
|Boiler capacity, water side||39,300 gallons|
|Length of electric wire||32 miles (approx.)|
Director of Generation
Dave MacDonnell, our Director of Generation, grew up as the second of seven children in Bath, Maine, known as "The City of Ships" for its place in our nation's shipbuilding history. A 1980 graduate of Maine Maritime Academy in Castine, Maine, Dave received a Bachelor of Science in Marine Engineering, and a U.S. Coast Guard license to operate boilers and turbines on merchant vessels. Dave has been an employee of BED for over 30 years.