It’s not just solar panels. Electric cars can be contagious, too.

We already know that solar power can be contagious. Studies have found that if you install a rooftop solar system, it increases the odds that your neighbors will too.

Now along comes tantalizing evidence that electric vehicles have a similar dynamic. When charging stations are more visible, people become much more likely to consider buying a plug-in car:

Placing charging stations at workplaces, where cars spend much of their time, will be uniquely powerful. When a workplace installs a charging station, employees are 20 times as likely to buy a vehicle with a plug, according to a survey from the U.S. Department of Energy.

That’s from a very smart piece in the Wall Street Journal by Christopher Mims titled “Why Electric Cars Will Be Here Sooner Than You Think.” The core of his argument focuses on economics: Batteries keep improving, and newer electric cars keep getting cheaper and are able to go farther on a single charge. Current EV models — the Nissan Leaf gets about 80 miles on a charge — are already sufficient to handle the vast majority of daily trips. Future models will be even better.

But the social angle is also important here. Right now, electric cars are still a niche technology, making less than 1 percent of the US fleet. But as the cars proliferate, more and more people will become comfortable with the idea of owning one. They’ll see their neighbors driving them. They’ll chat with co-workers about the ins and outs of recharging. They’ll see enough charging stations pop up that a plug-in vehicle no longer seems impractical.

Such network effects have, historically, been powerful in accelerating the adoption of new consumer technologies, whether it’s DVD players or smartphone apps. It’s a reasonable bet they’ll prove potent for electric vehicles as well.

Lately, some environmental groups have focused on a slightly different (but related) social aspect of adoption — car dealerships.

The Sierra Club recently sent its members out to see how easy (or hard) it was to buy electric vehicles at 308 car dealerships across the country. It’s fairly easy in California, but less so in other states trying to boost their EV fleets.

Many dealerships surveyed didn’t even have an EV in the lot. And those that did often didn’t display the cars prominently, or their dealers didn’t offer great information. From the report:

Of our respondents who asked to test drive an EV, they were told at 14% of the dealerships that the car was not sufficiently charged, including 22% of the Chevy dealerships and at 21% of the Ford dealerships visited.

Of the visits to dealerships with at least one EV on the lot, volunteers indicated that about 33% of the time the salesperson did not discuss the federal and state tax credits and rebates available to lower the cost of an EV.

Of the visits to dealerships with at least one EV on the lot, volunteers indicated that only about 50% of the salespeople they spoke with provided information on how to fuel the EV while traveling.

Of the visits to dealerships with at least one EV on the lot, volunteers found that 42% of the time EVs were either “not prominently displayed” or were only “somewhat prominently displayed.”

The Sierra Club report offered automakers and dealers some advice on making these cars more visible — such as making it easier to certify dealers in EV sales or providing more EVs on lots. (Tesla gets around this hurdle by selling its EVs directly in its stores, although many states have banned direct sales, so there’s no alternative to dealers there.)

Now, this is not to say that everyone would buy an electric car if they were more prominently displayed and salespeople were more conversant about their pros and cons. But again, the idea is that as EVs become less strange and more commonplace, adoption rates will presumably pick up — and even accelerate.

Here’s Mims’s conclusion (and you should read his whole piece): “It is the nature of disruptive technological shifts that it seems like nothing is changing — until it seems as if everything is changing at once.” Electric cars aren’t guaranteed to take over the world, but it’s not hard to see how they could be primed for a big lift-off.