AUGUSTA — The entire south side of the Augusta Civic Center would be covered in solar panels, filling the large auditorium inside with hot air, as part of a proposed series of $2.1 million in energy efficiency improvements.

However, plans for renewable energy systems at other city buildings were scrapped in favor of still new, but non-renewable, systems because the renewable energy solutions just wouldn’t save enough money to make the numbers work, officials said.

Together, proposed energy efficiency upgrades at Augusta Civic Center, Augusta City Center and Buker Community Center are projected to save the city $4.3 million over 20 years, based on current and projected future increases in the cost of the fuels used in those buildings now.

Ralph St. Pierre, assistant city manager and finance director, said the upgrades would save enough every year to more than pay the cost of borrowing funds to pay for them. The cost of borrowing the funds, St. Pierre estimates, would be about $133,000 a year, and the upgrades are expected to save about $144,000 a year. Once the loans were paid off, the city could save the $144,000 a year through reduced energy costs.

The proposal was originally based largely on renewable energy systems, including the solar panels still being considered for the Augusta Civic Center and a wood pellet boiler system proposed, but since rejected, for Buker Community Center.

“As (consultants) looked further at each of the buildings, and with the prospect of natural gas coming, it became apparent the renewables, other than potentially at the Civic Center, were not going to be a cost-effective solution,” St. Pierre told city councilors Thursday night. “So instead, they looked at energy efficiency upgrades that would have a positive cash flow tailored to the particular buildings.”

The lone remaining renewable energy proposal would put 4,000 square feet of solar hot air panels on the wall of the Civic Center which faces the University of Maine at Augusta and Maine Municipal Association building.

“At peak efficiency, at noontime, we can convert 80 percent of whatever energy is hitting this wall and convert it to usable energy to heat the space,” said Mick Dunn, of Biddeford-based Shift Energy, the supplier of the solar panels. “There’s a bypass damper, for the warmer seasons, we use as soon as we see higher temperatures than we want in the space. This is a wintertime application.”

Bob LaBreck, facilities manager, said the solar panels will also act as siding on the building, and the Civic Center’s 1970s siding is likely going to need to be replaced soon. So the solar panels could save the city from having to put new siding on one side of the building.

At Buker Community Center, an antiquated, oil-fueled steam heating system would be replaced with an entirely new heating system, first fueled by propane but with the potential to be easily converted to natural gas if and when gas becomes available in Augusta. LaBreck said the inefficient system now at Buker takes about $100,000 to heat the former school building.

The new system is expected to cut that in half.

At Augusta City Center, two 25-year-old cooling towers would be replaced with one new cooling tower and two oil boilers would be replaced with a new gas-fired boiler. LaBreck said the two oil boilers, which are only about five years old, would be reused elsewhere — one as a backup at Buker, the other as a new boiler for the city’s public works facility, where it would replace a 1940s boiler.

City councilors asked St. Pierre to draft a council order, with all councilors sponsoring it, for them to authorize city staff to put together bid specifications and seek bidders on the projects.

“It’s a good deal, regardless of what form of energy we end up using,” said Councilor Michael Byron.

Two competing companies, Maine Natural Gas and Summit Natural Gas of Maine, have proposed to build a natural gas pipeline from an existing pipeline in Windsor into Augusta, potentially laying pipe in the ground as soon as this summer. However, the work is currently on hold as the state considers an appeal, filed by Summit, of the state’s award of a bid to Maine Natural Gas to build a natural gas pipeline to state facilities in Augusta.

“I don’t think there’s any question natural gas is coming to Augusta; the question is when,” Mayor William Stokes said. “The momentum to get natural gas here is ongoing and I think it’s going to happen.”

Keith Edwards — 621-5647

kedwards@centralmaine.com