A Yarmouth-based company is moving forward with plans to build Maine’s largest solar energy farm on vacant land at Sanford’s municipal airport after winning key support from the city.

The Sanford City Council on Tuesday unanimously authorized City Manager Steven Buck to sign a lease allowing Ranger Solar to use 226 acres of city-owned airport land to build a 50-megawatt photovoltaic array. The utility-scale commercial project would generate power to be sold through the region’s electricity grid.

Ranger Solar intends to start construction in 2018. The project will include 176,000 solar panels and could provide enough electricity to power more than 8,000 homes. There are roughly 9,700 households in Sanford, according to the most recent U.S. census data.

“It is going to be the largest project in the state of Maine and one of the largest in New England,” Buck said in an interview Wednesday.

The project has been in the works for three years. When the city started discussing the proposal with Ranger, a Federal Aviation Administration moratorium on solar installations at airports was in place, Buck said. The proposal meets the agency’s rules on wind and glare and has since received approval from the FAA and the Department of Defense, which used to own the airport, Buck said.

Ranger estimates that the project will add $29 million in taxable investment to the city, as well as millions of dollars in rent if the lease is extended to the maximum 40-year term stipulated in the agreement. According to Ranger, the project will employ 94 full-time construction workers while it is being built, and nine full-time operations employees once it is up and running.

The project still needs to get environmental permitting from the state and authorization from ISO New England to hook into the electricity grid.

Ranger plans to build transmission lines to a Central Maine Power substation on Route 4, then sell the power it produces through private purchase agreements, Buck said. At least one local business intends to buy power from Ranger, the city manager said.

The dropping price of solar power equipment has made utility-scale projects more attractive. Utility solar comes at the same time a lot of older conventional power plants are reaching the end of their operational lifespans, and clean power alternatives such as mountaintop wind energy are facing opposition because of the aesthetic impact.

“Solar has a much more benign footprint, it’s not as visible and produces clean, on-peak power,” said Aaron Svedlow, Ranger’s director of environmental permitting.

A 1.2-megawatt array at Bowdoin College in Brunswick is now the largest solar installation in Maine, but Ranger and other companies are planning larger projects. Last year, the Maine Public Utilities Commission awarded an energy contract to Portland-based Dirigo Solar to provide 75 megawatts of electricity, and Ranger proposed a 50-megawatt project in Winslow, but the plan fell through because Ranger could not reach an agreement with the landowner. The company also is pursuing similar projects in Vermont.

Solar power advocates had hoped that a bill introduced in the Maine Legislature during the just-completed session would give the industry a boost and modernize Maine’s solar regulations. But the Legislature failed to override a veto by Gov. Paul LePage, who said the solar plan would benefit a small number of people who could afford to install solar panels at the expense of other electricity ratepayers.

Although the bill would have been positive for the industry at large, it would not have affected Ranger’s project directly, Svedlow said.

Sanford Mayor Thomas Cote said the solar project fits into the city’s other long-term plans, such as building the state’s largest technical high school and installing a municipal broadband network. Reaching an agreement on the Ranger project also shows that the city can build public-private relationships, he said.

“For the city, it is obviously very positive. Projects like this take a long time and it speaks to our ability to successfully manage these types of public-private partnerships,” Cote said.

“From a practical perspective, it allows Sanford to add value to our businesses that really care about their carbon footprint because they can buy locally produced clean power,” he said.

Under the terms of the initial five-year lease, Ranger will pay the city $10,000 up front and another $5,000 when construction starts. After construction begins, it will start paying $700 an acre per year in rent, or $158,200 annually. The initial lease can be extended for four five-year periods up to the 25th year and for 15 years in the final extension. In each extension, the per-acre rent can go up $100 or a percentage tagged to the consumer price index, with the increase capped at $150.

That income is enough to make the airport self-sufficient without using taxpayer money, Buck said. The solar arrays are considered personal property and don’t qualify for state tax breaks for businesses, so Sanford will get an increase in tax revenue from the development.