More than three months after the Summit Stage integrated its first electric buses into its fleet, the organization is optimistic about the future of the program, despite some hiccups along the way.

In October, the Summit Stage added three new Proterra electric buses to its fleet, part of an effort to eventually transition to 100% electric vehicles. Summit County Transit Director Chris Lubbers said the buses have largely met expectations, though officials continue to experiment with the buses to determine their full capabilities.

“We have found that they do perform well,” Lubbers said. “They’re quiet, and so far, the heating isn’t a problem in the extreme temperatures that we’ve endured recently. … Obviously, the range of electric buses hasn’t matched the range of diesel buses. We knew that going in. … We’re experimenting with that range. We don’t have exact numbers right now, but we have found them to be effective and to work well on multiple routes.”

The buses have been successfully used on the Copper Mountain and Frisco-to-Silverthorne routes, and Lubbers said they plan to begin using them on routes to Park and Lake counties in the near future.

But not all has gone according to plan. One bus has been out of working condition for more than 60 days due to a defective drive motor from the manufacturer. Lubbers said Proterra worked quickly to help address the issue, sending a core engineer to diagnose the problem, providing a new motor and installation, and extending the warranty.

Lubbers said the parts have been delivered, and the Summit Stage hopes to have the bus running again as early as this week. He noted that the other Proterra buses also have dealt with maintenance “downtime,” but for minor issues that he’d expect from any bus.

“Although disappointed, we are satisfied with the response we’ve received,” Lubbers said about the defective bus. “It’s still new technology. We are at least aware of the potential for bugs to be worked out.”

Lubbers said the buses are able to run for five to six hours at a time before they’re “cautiously” brought back in for charging when they have about 30% of their battery life left. Charging takes about four hours, Lubbers said. By comparison, the diesel buses equipped with auxiliary tanks can run for about 17 hours, though they frequently stop for driver changes and logistical reasons.

“We do expect (technology) to improve,” Lubbers said. “The organization will be careful, and at any point if we see any type of operational need that cannot be served, we’ll make sure that we have the proper equipment out there regardless of fuel type. But we are very optimistic that it will be electric.”

The buses cost about $875,000 each — compared to $570,000 for a diesel bus — plus $40,000 for charging infrastructure. About 80% of the costs were paid for via state and federal grants.

Summit County Sustainability Coordinator Michael Wurzel said that about 33% of the community’s emissions come from transportation and that the more a vehicle drives, the greater the impact of switching to electric.

“I think the diesel buses get about 4-5 miles to the gallon, and every gallon that is burned produces a little over 20 pounds of CO2,” Wurzel said. “Transitioning to electric, there’s zero tailpipe emissions. … So really the only way to reduce our emissions in the transportation sector across the board is to adopt electric vehicles.

“We do fundamentally believe here at the county that electric vehicles are superior to conventional ones, not just for their environmental benefits, but we think we’ll see fuel savings — electricity is cheaper than diesel — that these buses require less maintenance and that the technology will continue to advance and get better.”