Although California leads the nation in electric vehicle sales, with about 40 percent of the market, it is under pressure to meet aggressive goals that would require 100,000 chargers that are faster than traditional home outlets — enough to support one million vehicles — by 2020.

Beyond California, automakers face strict federal mandates to improve fuel efficiency and reduce carbon emissions. By 2025, their fleets must average at least 54.5 miles a gallon, more than double the current average of about 25 miles a gallon.

To reach that goal, analysts say, automakers have little choice but to expand the consumer market for vehicles that require a plug-in charge beyond the 120,000 sold last year. Over all, automakers sold about 16.5 million vehicles in the United States in 2014.

But developing that electric market has proved difficult, with charging companies struggling to figure out how to make money and even going bankrupt, despite generous federal support and, in some states, prohibitions on utilities entering the market for fear of stifling competition. California regulators had enacted one such ban but overturned it at the end of last year.

Mindful of what Dan Bowermaster, manager of electric transportation at the Electric Power Research Institute, a nonprofit utility organization, called the speed-bumps of developing the network, regulators and the industry were beginning to turn to the electric companies. Some private companies, like Ecotality, went out of business — even after receiving generous taxpayer support — and had difficulty maintaining the stations.

“Everyone has different opinions about whether or not the utility model is the right one, but it is regulated and every stakeholder can get involved,” he said. “What the utilities can do is, they have scale, so they can drive costs down.”

For the utilities, whose revenue is being squeezed by slowing growth in electric demand and, especially in states like California, the explosion in residential solar power, the charging business represents a potential boon.