The company Lincoln Renewable Natural Gas has filed a petition to construct a renewable natural gas plant at a farm in Salisbury.
If the plant is approved by the Vermont Public Service Board, it would be just the second of its kind in the United States.
Dan Smith, president of Lincoln RNG, says it's similar to the Cow Power program. Traditional methane digesters process manure to produce bio-gas and then burn the gas in a generator to create electricity. Creating renewable natural gas will start with the same step, producing bio-gas from cow manure, but the bio-gas will be processed to become bio-methane.
"Once you upgrade bio-gas into bio-methane at that point, it's interchangeable with pipeline natural gas. It's methane and it can be injected into a pipeline or compressed and delivered to a customer who can use it in the same form as natural gas delivered into a pipeline, used for heating fuel or it can also be used for vehicle fuel as well," Smith explained.
Most of the output of the plant will be piped to serve Middlebury College, which has a sustainability objective to take all of their number 6 heating oil offline. Smith says the college has achieved half of that goal with a wood chip heating plant, as well as conservation efforts. "This project will produce the equivalent for them of 640,000 gallons of number 6. Once the switch the number 6 to RNG [renewable natural gas] they'll be pretty close to being completely renewable fuel-sourced."
The remaining output of the plant will be sold to Vermont Gas, which is in the process of extending their natural gas pipeline from Colchester to Middlebury. The pipeline was approved, but is currently under review by regulators again. If it is built, the Lincoln RNG plant will connect to that pipeline.
In the meantime, some businesses in Middlebury, such as cheese-maker Agri-Mark Cabot are already using natural gas through a "gas island." That's a small distribution pipeline network that is filled with compressed natural gas, trucked by the company NG Advantage. That distribution line will be extended to Middlebury College this week. Vermont Gas will build a spur line from the gas island facility to the Lincoln RNG plant, about six miles south of Middlebury.
"The gas at that point will be piped in from the south to the gas island, and trucked in from the north to the gas island and serve the college, and the additional amount will go to the other customers that Vermont Gas serves in the gas island," Smith said.
While the larger Vermont Gas expansion project has been hampered by difficulty securing the landowner easements needed to build the pipeline, Smith says the spur pipeline to the Lincoln RNG plant will be placed in the road right-of-way.
The renewable natural gas plant has been in the work since 2008. Smith says new applications of technology are cumbersome. "My objective was to establish something on the leading edge. This technology is being employed all over the world, so it's proven technology, just not in the United States," he said, noting that he had hoped it would be the first of its kind in the country. "It just takes time to work through all of the different issues that are involved with a new type of technology. There are a lot of layers of every kind, regulatory, financial, and engineering that's involved with putting this together. It's the same discussion, yes it's new, but no it's proven-technology elsewhere and it's a question of getting the different folks comfortable with that idea, and it just takes time."
Lincoln RNG has asked for an expedited Public Service Board review process, which could take three to four months. If it's approved, the plant would be up and running by the end of the year.