The city will spend $3.8 million on four battery-powered buses, which will join the transit system’s fleet this summer.

The purchase will make Greensboro the first city in North Carolina with all zero-emission, battery-electric buses.

The new buses will replace diesel buses that have been driven past the recommended 12-year, 500,000-mile life. Officials estimate that each new bus will save taxpayers $325,000 over their lives, since they use less energy and need less maintenance than the diesels.

The city will pay for the buses with money from the transportation bond that voters passed in 2016, along with federal and private grants.