Transforming Waste into Energy

Transforming Waste into Energy
By Audrey McCollum

A herd of oxen grazes peacefully on a nearby meadow, treading between the cow pies that attest to active digestion. If only we could capture the methane gas rising from their waste, pipe it along the road and use it to heat or light our house, I thought.

My husband looked at me oddly when I recently voiced the idea, although Vermonters use that energy and term it “cow power”.

By chance, an e-mail soon arrived from Bob Walker of Thetford Center. A regional pioneer in conservation who founded and directs the Sustainable Energy Resource Group (SERG), he was aware of my recent columns about the Lebanon Solid Waste Facility. And he was ready, as always, to contribute useful information.

“Methane is the primary component of landfill gas and it is one of the primary greenhouse gases of concern, 22 times worse … than carbon dioxide,” he wrote (not specifically mentioning cow pies, but landfills surely include animal droppings). Interested in reducing the adverse environmental impacts of landfill gas and in bolstering the local economy through the circulation of benign “energy dollars,” SERG undertook a study of regional alternatives.

By the spring of 2006, SERG presented to the Lebanon City Council a report examining three options: Burning the gas to prevent its escape into the atmosphere (termed “flaming”); Piping the gas to a nearby business to use as fuel; Generating electricity in the landfill site. Readers wishing more technical detail may e-mail to SERG@valley.net for the study report.

Walker also commented, “In terms of technical ‘how to collect, clean and convert to energy’ questions, Marc may be more familiar.” Indeed, Marc Morgan, manager of the facility (who had come aboard after the SERG study was done) was extremely clear. On e-mail, he described the process in these terms:
• Collection pipes called gas wells are placed in the landfill.
• Those wells are connected to the pipes that transport the gas to a generator. Vacuums and fans are used to pull more gas out of the wells.
• At the generator, gas is used to produce electricity.
• The resulting electricity could be used on site and/or sent to the (regional) grid.
• If the gas is sent to an “end user” (such as Pike Industries or Carroll Concrete, which expressed interest to Walker in 2007), the gas would be piped to them. That gas would most likely be used for heating purposes.

Morgan, who has been working closely with facility engineers and Lebanon city management, notes that other possibilities are being considered too. Production of a compressed gas product to use in home heating or in vehicles is one; another is participating in the realm of carbon offsets. In that process, which I learned about while researching the topic of alpine skiing and climate change, facilities such as ski areas attempt to compensate for their production of greenhouses gases in snowmaking and operating lifts by investing in companies that are producing “green energy” (such as cow power!)

After reading my May 14 column about the Lebanon Solid Waste Facility (which Walker terms the landfill), a curious reader had e-mailed: “On gas to energy … this is so promising and we hope that it is beyond the talking stage. Did they say when this would be happening and where the methane would be taken?”

Morgan responded with reassurance, also noting the complexity of the undertaking.

“We are moving forward with this project. It just takes time to do sampling, testing, design and construction. Technology has changed a lot too. I want to be sure that the city is able to take advantage of new ideas to best manage this material,” he wrote.

“We have sent out a Request for Qualifications to landfill gas companies” (to determine which ones fit the needs of the city), wrote Morgan. “This is done before a proposal is developed for a project … It is our hope to have a Landfill gas company on board by the end of 2009 and a project designed in 2010, with construction in 2011.”

And maybe by then our neighborly oxen will help to warm and heat our house – or allow us to enjoy the fantasy.
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Audrey McCollum can be reached at amccollum@valley.net This column was published in the Spectator on 6/11/09