Gas from cow manure could help heat Maine homes and businesses starting in 2021, under an innovative proposal announced Thursday by Summit Natural Gas of Maine.

Summit says it wants to build a $20 million anaerobic digestion facility on a farm in Clinton, where it will receive dairy manure from multiple family farms in town and from other areas in Maine. The manure will be heated and decomposed, creating renewable natural gas, or biogas. The gas will then be cleaned of impurities and injected into Summit’s pipeline distribution system.

Clinton was selected because it’s on the pipeline route in the Kennebec Valley and is considered Maine’s dairy capital, with five farms that make up 17 percent of the state’s milk production.

Summit is partnering with Flood Brothers Farm, Caverly Farms, Misty Meadows Farm, Wright Place Farm, Taylor Dairy Farm, Veazland Farm, Simpson View Farm and Gold-Top Farm to obtain organic waste for its facility, which will be located at the Flood farm.

Summit anticipates the digester will supply approximately 125,000 MMBtu of gas a year, equal to roughly 45 percent of the company’s Maine annual residential gas demand.

Summit expects the digester will be operating early in 2021, pending approvals and permitting.


In announcing its program, Summit is at the vanguard of an emerging trend among natural gas distribution companies.

Earlier this year, Southern California Gas said it plans to replace 20 percent of its conventional supply with renewable natural gas by 2030. To get started, it’s pursuing a plan with state regulators to replace 5 percent of its supply with renewable gas by 2022.

In 2018, SoCalGas began pumping so-called RNG from an anaerobic digester built by a waste hauling company, fed by organic waste collected from California cities.

In Maine, making biogas from dairy cow manure isn’t a totally new idea.

Since 2011, the Exeter Agri-Energy operation at Stonyvale Farm, northwest of Bangor, has been converting both cow and food waste into heat and electricity. It also produces organic fertilizer, soil additives and animal bedding.

Biogas or RNG is considered to have strong benefits for fighting climate change. Besides replacing fossil fuels, it creates a use for the methane that otherwise rises into the atmosphere from livestock waste. Methane is a more-powerful greenhouse gas than carbon dioxide.


In the United Kingdom, one million homes now are heated with what’s known there as green gas, according to a report picked up by the Coalition for Renewable Natural Gas.

The farm-to-pipe program is one of three steps Summit announced on Thursday, as part of an effort to stimulate the local economy while fighting climate change.

It also plans to match 5 percent of its Maine residential gas demand for the next year by purchasing renewable gas attributes, which are similar to carbon credits. This action has no cost to ratepayers, the company said.

Summit also want to develop a voluntary option for Maine customers to fund the purchase of RNG attributes to help reduce their carbon footprint. This would be similar to programs in which electric customer buy green power from sources such as solar and wind.

A subsidiary of Summit Utilities in Colorado, Summit Natural Gas of Maine began building a pipeline system here in 2013. The company says it has invested more than $340 million and installed more than 250 miles of pipe throughout the Kennebec River valley and in Cumberland, Yarmouth and Falmouth. Recently, it announced a $4 million plan to expand into the business district of West Falmouth.


This story will be updated.


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