Andrew Kahrl, left, a solar design specialist at ReVision Energy, reviewed the first draft of a solar power agreement with Bath city councilors Wednesday. Kathleen O’Brien / The Times Record

BATH — Bath could shave 20% off its annual municipal electric bill if it adopts a new solar power agreement.

The city is considering a partnership with solar power company ReVision Energy to build a 1.8-megawatt system that would supply 80% of the city’s power usage, not including schools and the wastewater treatment plant.

If the city agrees, it would contract with ReVision Energy or an investor to buy solar-produced power at a lower rate rather than purchasing the solar panels themselves, which would cost $3.8 million.

Bath pays about $400,000 per year for electricity. Town officials say solar power would save $80,000 in the first year. Over the 20-year contract period, that savings would total about $2.5 million, according to ReVision solar design specialist Andrew Kahrl.

City Manager Peter Owen was cautious when reviewing the proposal with the city council Wednesday.

“Municipalities aren’t businesses; we don’t make investments at the taxpayer’s expense,” said Owen. “We have to make sure when we make an investment it’s going to be for savings.”

Kahrl said Bath would need 7 to 8 acres of solar panels to power its facilities. While the company isn’t yet certain where the solar panels would be built, he said the company is looking at two possible locations — one in Dover-Foxcroft and one in Waldoboro.

Adopting solar power would also eliminate 2.6 million pounds of carbon dioxide from being released into the atmosphere, the equivalent of taking 250 cars off the road, according to Kahrl.

“The Gulf of Maine is warming faster than any other part of the North Atlantic Ocean and our fisheries are incredibly vulnerable to acidification so these things are really critical items to the citizens of Bath, the surrounding area, and our whole economy,” said Kahrl. “Even if someone doesn’t care about the climate, there’s a strong fiscal case for the project.”

Rockport, Portland, South Portland and Limestone all have contracts with ReVision Energy, among others.

Kahrl encouraged Bath to invest in solar power this year because the price of solar power contracts is expected to increase after 2020.

“In 2020, the Federal Tax Credit is worth 26% and next year it’ll be worth 22%, so the cost of power purchase agreements is going to increase for projects built next year,” said Kahrl.

He also pointed to Maine’s current “pro-solar” administration, adding Bath’s potential solar power agreement would align with Gov. Janet Mills’ plan to make the state carbon neutral by 2045.

Mills, who installed solar panels at Blaine House in November, signed an executive order last year directing agencies to develop and implement sustainability plans to meet or exceed the state’s carbon reduction goals.

Owen said the city has looked for environmentally-friendly alternatives to power municipal buildings for the past year. City councilors are now able to entertain ideas of using solar power to power municipal buildings after Bath voted to amend a charter that limited the city’s ability to enter into long term contracts two months ago.

The charter previously limited contracts on multi-year fund commitments for goods and services to five years. The intent was to prevent a city council from making decisions that would force the panel to uphold a commitment of funds five years down the road.

Under the approved amendment, the council would review any contract running more than five years on a case-to-case basis, and six councilors would have to approve a waiver.