A utility industry trade group calls them a “huge, albeit long-term opportunity” for the power industry, which could charge the plug-in vehicles overnight, when electric demand is low.

“Despite the significant opportunity … we are not yet leading by example,” the Edison Electric Institute said in a report last year.

It’s an opportunity that an early-stage company in Minnesota hopes to seize.

Universal Tactical Systems, based mainly in the founder’s home in Wyoming, Minn., has designed an electric-powered, medium-duty truck that could be equipped with an articulating arm and bucket used by utility workers to repair power lines.

The idea is that power companies could deploy such trucks all day, and plug them in at night. The truck, called Zeus, is expected to go 120 miles without a charge, enough for urban utilities, said designer and CEO Bob Grinstead.

“You have a work truck that goes from point A to B and sits there all day then comes back — it makes sense,” said Grinstead, who has designed vehicles, including fire trucks, and currently works on vehicle research and development for another, unrelated company in Minnesota.

While the idea may make sense, making a prototype takes dollars. The principals in the Minnesota company are not billionaires like Elon Musk, the co-founder of PayPal who launched Tesla Motors, the luxury electric carmaker.

To get the Zeus from design stage to rubber on the road, Grinstead and a partner, marketing and business development consultant Brian Graff of Eau Claire, Wis., seek angel investors willing to risk $500,000 on a prototype.

“They want to see it on the ground,” Grinstead said of utilities and other potential buyers.

Grinstead, formerly a project engineer for Michigan-based emergency vehicle maker Spartan Chassis, said up to 60 percent of the Zeus truck’s parts could be purchased from suppliers. While not exactly “off the shelf,” equipment like motors and regenerative brakes is available from suppliers with track records in fabricating such parts, he said.

Zeus’ chassis, designed to be lightweight but able to withstand the stress of an articulating arm, is a key component that will be built by the start-up company. Grinstead said his design takes ideas from ladder trucks used by firefighters that undergo the same stresses.

Even if the prototype gets built and lives up to its promise, it could be a hard sell to utilities. Fleet managers inevitably will compare the cost to that of a diesel truck.

“There is a general interest in electric vehicles,” said Doug Shoemaker, retired fleet manager for Xcel Energy in Minneapolis who now volunteers for the Minnesota Renewable Energy Society. “What everyone in the utility industry is concerned about is, ‘Will it add cost to my operation?’ ”

Nina Kisch, a fleet manager for Pacific Gas & Electric in California, said that utility recently acquired two plug-in hybrid bucket trucks from Efficient Drivetrains of Milpitas, Calif. Their batteries can export electricity to temporarily restore power in a blacked-out neighborhood, she said.

“When you look at bringing in new technology, if you are going to offer something that’s a benefit to our core business, which is keeping your lights on, then the costs are seen in a totally different light,” said Kisch, who was the lead author of the 2014 Edison report on utility EVs.

But Kisch said a pure plug-in, like the Zeus, may not be the best option for emergency utility work. “We have to go anywhere at any time,” she said. “For that reason an extended-range plug-in, something with a generator or an engine, is really the best of both worlds for us.”

Zeus’ developers acknowledge utilities’ interest in so-called “exportable” power and said they have chosen batteries capable of supplying emergency power. But the power-export feature is not designed into the truck yet.

Indeed, no pure plug-in electric utility bucket trucks are on the market.

Despite the start-up company’s focus on utilities, Grinstead and Graff said the Zeus could be fitted out for various purposes. Potential customers, they said, include universities, airports and municipal governments that rely on trucks during the day, but can park them for charging at night.