A South Carolina company that’s building zero-emission electric buses made a stop in Spokane on Tuesday to show off the latest version of next-generation transit technology.

Spokane Transit Authority officials are considering using electric power for a proposed central city line that would run from Browne’s Addition on the west to Spokane Community College on the east, passing through downtown and Gonzaga University.

The battery-powered vehicle built by Proterra can be equipped with fast-charge technology that would allow the bus to operate all day long. The charging would take place on the line during five-minute breaks in service.

Proterra brought the bus to Spokane as part of a national tour and to show to STA officials who examined it at its operations center on West Boone Avenue.

The initial vision for the central city line was a trolley bus powered by electricity through overhead lines, but STA officials are considering options like the Proterra bus, which would not require overhead lines and would cost less.

The line, which is in the planning stages, would cost more than $70 million and is part of a broader effort to build a high-performance transit network across the Spokane urban area. The improvements would require a sales tax increase. Federal grants could pay for a large portion of the project.

Proterra said its electric buses are much more energy efficient than conventional diesels. Testing rated the electrical energy use as equivalent to 21 miles per gallon of diesel.

The $800,000 sticker price on the 41-foot model is high compared with the Gillig buses currently in the STA fleet. A conventional Gillig diesel bus costs $378,000 and a Gillig electric hybrid diesel is $550,000.

However, savings on fuel and maintenance would more than pay for the added cost up-front over the expected 12-year-life of the Proterra, said Dale Hill, company founder.

The bus sports curving lines intended to accentuate its modernistic corner of the bus market.

“It’s more the European appearance,” Hill said.

The design has limited the number of batteries on board to keep overall weight down. The body uses composites, carbon fiber and fiberglass. As a result, the exterior is very durable, Hill said.

The batteries are contained beneath the floor of the passenger compartment. In case of a crash, the electrical charge would be contained by nonmetallic construction materials, enhancing passenger safety, he said.

The bus, which has seats for 40 passengers, offers greater leg room than Gillig buses. Its aisle and exit doors are wider. It also has a rear window.

Proterra, of Greenville, South Carolina, was founded in 2004. Its buses are operating in nine U.S. cities.

King County’s Metro bus system has placed an order for the Proterra. The model brought to Spokane is on a national tour of 57 cities.

In March, STA did a monthlong trial of an all-electric Chinese bus through a U.S. branch of BYD Co. Ltd.