What happened

General Motors (GM -0.17%) stock is up 5.9% as of 12:35 p.m. ET Wednesday -- and PG&E Corporation (PCG 1.87%) has jumped 2.8% -- after The Wall Street Journal reported that the two companies are teaming up on a program "to test the use of electric vehicles to power homes during [power] outages."  

The companies themselves disclosed this project in a press release Tuesday.  

General Motors Electric Hummer SUV.

Image source: General Motors.

So what

General Motors will provide the electric vehicles (EVs), "equipped with cutting-edge bidirectional charging technology," for this test project, which is scheduled to begin this summer. "Multiple GM EVs" will be involved, but GM didn't say which models. The companies also did not say how many homes will be powered in the project, other than to advise that it will include "a small subset of customers' homes."

Assuming all goes well, though, the companies plan "to scale the pilot with the goal of opening larger customer trials by the end of 2022."

Now what

What does this mean for General Motors? Well, GM says its goal is that, "by the end of 2025, GM will have more than 1 million" EVs capable of doing such bidirectional charging in North America. If the PG&E pilot goes well, it "could help the company market its EVs as backup generators in emergencies, adding to their consumer appeal," reports the Journal  -- and thus help GM to grow its sales of electric cars and trucks.

Granted, this is not a unique idea that GM and PG&E have come up with. As the Journal points out, GM rival Ford Motor Company has also promoted the ability of its F-150 Lightning electric pickup truck to serve as a backup battery for consumers' homes. Still, even if GM didn't come up with the idea, now it must prove that it, too, can provide this functionality if it wants to compete with Ford in EVs.

The game of electric automotive one-upmanship has begun.