AUGUSTA — City councilors reacted favorably Thursday to a proposal to invest $375,000 to bring three-phase electrical power to the Hatch Hill landfill, which could allow the city to make electricity using methane gas produced by rotting garbage.

While using methane gas already being produced and captured at the landfill to produce electricity would require roughly $2 million in additional investment beyond adding three-phase power, that investment, city administrators and a consultant say, could be paid back, and then some, in savings in the city’s electricity bills.

However, that payback 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 would 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.

The PUC is considering changes that could make net metering less beneficial to small power producers, which the city would be. However, Richard Silkman, a founder and partner of Competitive Energy Services, an energy services consultant working for the city on the proposal, said the currently proposed new rules before the PUC still would allow the city to pay for the energy project and bring the city savings beyond the investment payback.

“Net metering arrangements are essential to this kind of project, because there is (little demand for electricity) at the landfill; so whatever you generate there, you’ve got to bring it somewhere to be used,” Silkman said. “Should those rules, or law, change at some point, then you’d have to re-evaluate. But we think there is value, to the city, in savings to be realized.”

Ralph St. Pierre, finance director and assistant city manager, said if the city gets a system up and running and then the net metering rules change, he anticipates the city would be grandfathered, and would be allowed to continue getting a credit for its electricity produced by the system under the rules in place at the time the system went online. He said that has been the PUC standard practice previously.

But before the city could build a system to generate power at Hatch Hill, three-phase power needs to be in place.

And having three-phase power would have other benefits at Hatch Hill, Public Works Director Lesley Jones said, by allowing heavy equipment there to run more efficiently and reliably.

But perhaps the most intriguing benefit of having that higher-grade form of electricity at Hatch Hill landfill is that it could allow the city to move forward with the proposal to build a system to use methane gas produced as mountains of garbage at the landfill decompose, to produce electricity that would be fed into the electrical grid and reduce the city’s electricity costs.

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

City Manager William Bridgeo said a recently completed engineering report by Competitive Energy Services confirmed city staff’s previous assessment that the city could generate enough electricity at Hatch Hill for the potential project to return a positive payback on the city’s investment.

But three-phase power would be needed at Hatch Hill to handle the new system, and the landfill has only singe-phase power, which comes via a line through the woods from Route 3 installed in the 1960s, according to Jones.

Bridgeo and Jones said even if the city never moves forward with a proposal to build a facility to convert methane to electricity, having three-phase power at Hatch Hill would have benefits.

Jones said several pieces of equipment at Hatch Hill should operate on three-phase power, such as recycling balers and leachate pumps. Without access to it, the city instead uses converters and variable frequency drives to run that equipment, but she said doing so makes it less efficient and shortens the life span of the motors.

Bringing three-phase power to the site would cost about $375,000, which Bridgeo said could come out of the Hatch Hill enterprise fund, with no effect on the city’s property tax rate. Jones said Bob LaBreck, the city facilities manager, has been working with CMP on a proposal to bring three-phase power to Hatch Hill from South Belfast Avenue, which would be less costly than bringing it from Route 3.

Jones said three-phase power also would be more reliable, resulting in fewer power outages at the landfill.

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

Bridgeo said the city also, longer term, plans to study the potential for installing solar panels at Hatch Hill, which could allow the site to produce more electricity on top of that potentially produced by the methane conversion system.

Councilors are scheduled to vote on the proposal to bring three-phase power to Hatch Hill at their next business meeting, scheduled for Thursday.

Bridgeo said if councilors approve and the proposal move forward, the system could go online in early 2018.

Over the last several years, the city has made other energy system upgrades at city facilities, including installing heat pumps and microturbines at Augusta City Center, as recommended by a study.

St. Pierre said the energy-producing part of the proposal will come back to councilors for consideration later, and consultants and the city staff will work to provide details on the cost and potential payback of the proposal.

Keith Edwards — 621-5647

[email protected]

Twitter: @kedwardskj