AUGUSTA — City councilors on Thursday approved a plan to spend about $240,000 to design a system to use methane gas produced by decomposing garbage at Hatch Hill landfill to make electricity and reduce the city’s electric bills.

The city-owned landfill that takes solid waste from residents in several area municipalities is expected to produce enough methane gas from decomposing garbage to power generators for the next 15 years, according to a report produced as officials consider building the system to use landfill gas to produce electricity.

The electricity the system produces would be fed into the electrical grid, for which the city would receive a credit on its Central Maine Power electric bill to offset the cost of powering up to nine different city and school buildings.

Councilors voted 5-0 on Thursday to appropriate $240,000 from the Hatch Hill expense fund to be used to pay for the system to be designed.

At-Large Councilor Marci Alexander reminded city staff they need to do a more in depth analysis of the return on investment expected from the project before it proceeds too far.

“I want to make sure we’re still in agreement,” she said. “We’re going to have the life-cycle cost analysis done at the beginning of the project.”


Ralph St. Pierre, finance director and assistant city manager, said that would be done. St. Pierre told councilors last week an estimated return on investment could be produced by June. He said, however, he’d like to keep work on the proposal moving.

St. Pierre said if the numbers don’t look good, the city can halt the project at any time, though he expressed confidence the project will be able to pay for itself, and then some.

Engineers with Portland engineering firm Woodard and Curran who studied the landfill’s potential as a source of fuel said it should produce enough gas to produce 350 kilowatts of electricity a year, for 15 years, and potentially more.

City officials said the project could be considered viable if it can reliably produce 350 kilowatts of electricity a year, which would be enough to pay back the estimated $1.9 million cost of building the system in 12 to 15 years, with the potential to return revenues beyond that.

Projections in the Woodard and Curran report indicate it can produce that much electricity.

The city already captures, and burns off with a flare, methane gas produced at the landfill to prevent it from escaping into the environment.


The payback on the project would rely on controversial net metering rules, which could be changed by the state Public Utilities Commission. Under net metering, utilities credit the bills of small energy generators for the full retail price of all the electricity they send into the grid. The city proposal would rely on net metering provisions that could allow the city to get about 8.5 cents per kilowatt hour in credits it could use to pay electricity bills at some of the city and schools’ biggest energy-using buildings, such as the Augusta Civic Center and Cony High School. And it would cost an estimated 6 cents per kilowatt hour to generate that electricity at Hatch Hill, using methane from the landfill to power generators that would produce electricity, according to a previous study.

The city could designate up to nine sites where the electricity usage would be included in the net-metering plan.

The PUC has recommended changes that could make net metering less beneficial to small power producers, which the city would be. However, an energy services consultant working for the city on the proposal said previously the currently proposed new rules still could allow the city to pay for the energy project and bring the city savings beyond the investment payback.

Producing electricity at Hatch Hill would require the addition of three-phase power at the site, which could be done as part of a separate, approximately $375,000 project. Councilors approved that project in a previous vote.

While the current landfill is projected to be full in 12 to 15 years, the facility is expected by city officials to still be used as a disposal site, where three-phase power would be needed. And the waste there will continue to produce methane gas, Public Works Director Lesley Jones said, for about 25 years after the last day solid waste is put there.

Keith Edwards — 621-5647

[email protected]

Twitter: @kedwardskj

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