SCARBOROUGH, Maine — Town councilors on Wednesday approved a contract to outfit municipal buildings with solar panels and a new heating and cooling system.

By unanimous votes, with Councilor Kate St. Clair absent, councilors authorized Town Manager Tom Hall to reallocate more than $157,000 as the final funding needed to install a Tri-Gen system in Town Hall that will provide electricity, heating and cooling to the building, and possibly electricity for the high school.

Councilors also authorized Hall to sign a power purchase agreement with Scarborough Solar LLC to place solar panels on the North Scarborough fire station on Saco Street and the Community Services building on Quentin Drive near Wentworth Intermediate School.

Hall was also authorized to sign a revised $255,000 purchase option agreement with Habitat for Humanity of Greater Portland for the sale of five acres of land near 75 Broadturn Road in order to build affordable housing. The option is good until Sept. 30.

The final funding for the Tri-Gen system completes about $873,000 needed for equipment, construction and consultations and means installation work could begin this spring, Hall said.

The bulk of funding was set aside with $500,000 in the current Capital Improvements Plan; a grant from Efficiency Maine added $216,000. The 2009 CIP fund for Sawyer Road improvements was tapped for almost $66,000, and more than $91,000 was taken from the Public Safety Building Reserve Account.

The system was designed by Scarborough-based Self-Gen to be installed outside Town Hall. Fueled by natural gas to generate electricity, the system also recaptures what Hall called “high-temperature exhaust” to heat and cool the building.

Because more electricity will be generated than consumed, the excess power can be delivered to the high school. A presentation about the system in March 2013 also cited U.S. Environmental Protection Agency claims that “harmful emissions” can be reduced by 25 percent.

The entire system is expected to run at 75 percent efficiency. Conventional systems operate with about 49 percent efficiency, according to the data supplied by Hall.

The system is also expected to pay for itself in four years through reduced energy costs and electricity credits for powering the high school.

Former Council Vice Chairwoman Judy Roy participated in discussions leading to the plan and praised the town for stepping forward to reduce energy costs and emissions as part of a long-term strategy first considered as long as eight years ago.

“It’s an exciting order and I wish I could vote on it,” Roy said.

The power purchase agreement to buy solar energy is essentially the same plan already in place at the South Portland Planning and Development Office at the corner of Sawyer and Ocean streets.

The 20-year agreement with Scarborough Solar LLC allows the company, set up by Portland-based Revision Investments, to install the solar panels and gain the federal tax credits, while selling the town the generated power at 2 cents per kilowatt hour less than the market rate.

The sales agreement lasts for at least six years, and the town has an option to buy the set-up for a minimum of $72,000. Revision Investments has pledged to donate any sale proceeds above $73,000 to the town.

The town is not required to spend any money for the installation of the panels.

The option signed with Greater Portland Habitat for Humanity was revised to scale down the project from 13 homes to 17, but the nonprofit will remain as the primary developer. The land was obtained by the town from the Maine Turnpike Authority.