CHARLOTTE — Charlotte is now in the solar energy business, following a City Council vote last week to partner in building a 35-megawatt solar farm in Iredell County.

The city says that, with Monday’s vote, Charlotte became the most populous U.S. city to obtain renewable energy through a utility “green tariff” such as Duke’s Green Source Advantage program. At peak capacity, the solar farm will produce enough energy to power 10,000 homes a year, the city says, and reduce carbon emissions by the equivalent of taking 12,000 vehicles off the road.

Under a Duke Energy program that lets large customers negotiate directly with solar developers, the company’s headquarters city will team with two companies, Carolina Solar Energy and Ecoplexus, to build the solar farm north of Statesville. It’s expected to be operating by 2022.

The city expects emission-free solar energy to offset about 25% of the carbon emissions from city-owned buildings over the next 20 years, jump-starting a goal set in 2018 of becoming a low-carbon city by 2050. As part of that goal, Charlotte aims to achieve zero net carbon emissions from municipal buildings and its fleet by 2030.

“Not only does this 35-megawatt solar energy project get us 25% of the way towards our (carbon) goal in a very short time, but it contributes to building the green economy and improves our citizens’ quality of life,” Heather Bolick, the city’s energy and sustainability coordinator, said in a statement.

Under the program, customers enter into trilateral agreements among the customer, the solar developer and Duke. Duke buys the solar energy generated by the projects and credits the customer’s account. The customer keeps renewable energy certificates that prove that a percentage of its energy use is from a renewable source.

The city won’t pay any upfront costs for the project, which will be borne by the developers, Bolick said by email.

The solar farm is expected to save the city nearly $2 million in energy costs over 20 years. That’s because Duke’s costs of generating electricity are likely to rise over time, Bolick said, while the cost of energy produced by the solar project remains flat.

Charlotte is making other moves to reach the 2030 zero-carbon goal, she added. Among them are designing five new police stations last year that either have or can be readily fitted with solar panels, buying electric vehicles and making city buildings more energy efficient.

Duke tested the concept — teaming large customers with solar developers to reduce their carbon footprint — in 2015 and 2016. Tech giants Google and Cisco, which operate in North Carolina, were among the initial takers.

Last August, the state Utilities Commission gave Duke approval to let the Green Source program offer up to 600 megawatts in solar agreements. Of that amount, 100 MW was reserved for military installations and 250 for UNC institutions.

Customers, now including Charlotte, snapped up the 160 MW allotted for customers of Duke Energy Carolinas, the utility that serves western North Carolina. Duke has asked the Utilities Commission for permission to open up to customers statewide the 90 megawatts that had been reserved for Duke Energy Progress, serving the state’s eastern end.

Charlotte is the first municipality to take part in the program.

“It’s really very positive for the program that more cities are talking about lowering their carbon footprint, and this is a reflection of a program that cities can take advantage of,” said Duke spokesman Randy Wheeless.

Duke itself owns 40 N.C. solar farms and says it connected more than 500 MW of new solar capacity in 2018.