When Car2Go launched its car-sharing service in San Diego about five years ago, its entire fleet was composed of electric cars.

It was a move that made San Diego officials smile, as the city is undertaking an ambitious plan to cut carbon emissions.

But now Car2Go is withdrawing the fleet of Smart Fortwo Electric Drive city cars and replacing them with gasoline models.

The switch from electric to gasoline was prompted by a lack of charging infrastructure in the area, reportsĀ The San Diego Union-Tribune.

Car2Go, which is owned by Smart parent Daimler, made San Diego the only city in North America with an all-electric fleet when it began operations there five years ago.

That decision was based on an assumption that San Diego’s charging infrastructure would grow more rapidly than it actually did.

Car2Go Smart ForTwo Electric Drive in San Diego

In particular, Car2Go expected Ecotality to follow through with a promise to install 1,000 public charging stations in San Diego.

Instead, Ecotality went bankrupt in 2013, after installing only 400 of the stations.

With the currently available infrastructure, range anxiety remains common among customers, Car2Go said.

ALSO SEE: Utilities To Lead Surge Of Electric-Car Charging In Southern California

An average 20 percent of the fleet is also unavailable at any given time because cars are being charged or are in need of a charge, the company said.

In January, local utility San Diego Gas & Electric announced plans to install 3,500 charging stations across its area of operations.

But that project won’t get underway in time to affect Car2Go’s decision.

Zipcar

The company plans to begin switching over its fleet May 1, and expects the switch to be completed by the end of the month.

Local environmental leaders and city officials reacted strongly to the decision, with some describing it as a regression.

Car2Go presently operates 400 vehicles in San Diego, and has 40,000 members in the city.

MORE: Car2Go Cutting Out Portland’s Lower-Income, Racially Diverse Areas? (Aug 2015)

The fleet represents a small fraction of the thousands of cars on San Diego roads, but officials feel electric-car sharing is an important part of a plan to cut carbon emissions in half by 2035.

Car sharing plays a major role in San Diego’s transportation plans because official view it as a way to fill gaps between mass transit and shorter-distance solutions like bicycling.

The city recently announced Zipcar as its second car-sharing operator. That company uses hybrids in other cities, but no electric cars.

BMW DriveNow service launches in San Francisco

San Diego is also reportedly looking to land BMW’s DriveNow as a third car-sharing service.

DriveNow previously operated with a fleet of electric cars in San Francisco, but shut down service there last November.

[hat tip: John Higham]

This story originally appeared on Green Car Reports. Copyright 2016