There are more electric-car charging points in Japan than there are gas stations.

That surprising discovery comes from Nissan Motor Co., which reported that the number of power points in Japan, including fast-chargers and those in homes, has surged to 40,000, surpassing the nation’s 34,000 gas stations.

The figure shows that in the relatively brief time since electric vehicles were introduced, the infrastructure to support them has become bigger than what the oil industry built over decades in the world’s third-biggest economy — at least by this one measure.

Why that matters is obvious. Nissan’s battery-powered Leaf can travel 135 km on a charge, and the anxiety of being stuck away from home without power has restrained consumer demand. As the charging network expands and batteries become more powerful, that concern will wane.

“An important element of the continued market growth is the development of the charging infrastructure,” Joseph G. Peter, Nissan chief financial officer, told analysts on a conference call.

As charging stations become more common, electric-car support services are also emerging. Open Charge Map, for example, operates an online listing of public charging points worldwide. A mobile app combines the data with GPS technology to guide drivers to the nearest site.

Of course, gas stations typically have multiple pumps and can serve more vehicles in a day than an electric-car charging point.

Also, one criticism of Nissan’s number is that many of those charging sites are in private garages. Considering the emerging so-called sharing economy, such as the online home-sharing service operated by Airbnb Inc., homeowners may soon be willing to make their chargers available to other drivers.

And more charging locations are being built all the time. Automakers have recognized that oil companies are unlikely to install plugs next to gasoline pumps, and are building their own networks.

Tesla Motors Inc. has its own network of charging stations, and Bayerische Motoren Werke AG, or BMW, and Volkswagen AG announced in January that they are joining the network operated by ChargePoint Inc., and plan to build as many as 100 fast chargers along the busiest corridors of the U.S. coasts, from Portland to San Diego in the west and from Boston to Washington, in the east.

Utilities are joining in. Great Plains Energy Inc., the Kansas City, Missouri-based utility holding company, announced in January plans to build a network of more than 1,000 charging stations in the region by mid-2015. Charging will even be free to everyone for the first two years.

Given that there are only about 9,000 public charging stations in the entire U.S., the initiative gives Kansas City, the nation’s 29th largest metropolitan area, a chance to become the nation’s electric car capital with as much as 10 percent of the nation’s chargers.

Kansas City may not be able to retain that position. PG&E Corp., owner of California’s biggest utility, asked regulators Feb. 9 for permission to build a network of about 25,000 chargers in public areas over a five-year period.