It's long been assumed that while passenger vehicles may well start to transition to electric drive over the next decade or two, heavy commercial trucks won't.

The energy density of liquid hydrocarbon fuel is particularly well suited to moving vehicles that can weigh 10 times the 2-ton weight of a passenger car.

But a handful of companies are forging ahead with electric and series-hybrid trucks anyhow, one of them being Nikola Motor Company.

DON'T MISS: Nikola One 2000-hp natural gas-electric semi truck announced

In May, Nikola (pronounced NEEK-oh-la) unveiled its design for a natural gas- and electric-powered Class 8 commercial semi truck to be called the Nikola One.

The company, which had operated in stealth mode before April, now claims it has achieved "100 percent zero emissions" on its prototype, without providing specific test details.

Founder and CEO Trevor Milton said yesterday that Nikola had achieved "the Holy Grail" of the trucking industry: "a zero-emission truck ... that can haul 80,000 pounds [for] more than 1,000 miles ... without stopping."

Nikola One electric semi truck

Nikola One electric semi truck

After that, he said, "the Nikola One requires only 15 minutes of downtime before heading out for the next 1,000 miles," presumably for refueling.

The company, named after famed electrical engineer Nikola Tesla, plans to unveil a running prototype of its truck in Salt Lake City, Utah, on December 2.

The Nikola One is fueled with natural gas, though the turbine it uses to generate electricity can run on a variety of fuels.

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A 320-kilowatt-hour battery pack is charged by the turbine, and energy is also captured via regenerative braking.

[NOTE: An earlier version of this article erroneously claimed that the Nikola One did not include a plug to recharge its battery pack from the grid. It does, but that is not anticipated to be the main energy source for the truck during continuous operation. We apologize for the error.]

It is powered by six electric motors, rated at a combined 2000 horsepower and 3700 pound-feet of torque.

Nikola One electric semi truck

Nikola One electric semi truck

With its compressed natural-gas tank fully filled, Nikola claims a 1,200-mile range for the truck—and operating costs that will be half those of conventional diesel trucks.

Yesterday's announcement indicated that the company plans to lease each Nikola One tractor for $4,000 to $5,000 per month, depending on configuration and options.

It will also include enough fuel for the first 1,000,000 miles in the sale price, which it says can potentially offset 100 percent of that monthly lease cost just in savings over diesel fuel.

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The average Class 8 truck today burns approximately $400,000 in diesel fuel annually, Nikola says, as well as requiring $100,000 or more in maintenance costs each year.

Famed electrical engineer Nikola Tesla, scanned image from postcard c. 1890.

Famed electrical engineer Nikola Tesla, scanned image from postcard c. 1890.

Nikola claimed in June that it had received reservations for more than 7,000 of its trucks, including deposits, totaling more than $2.3 billion. (That would appear to indicate that each reservation was worth roughly $300,000.)

In the press statement, Milton responded to a hypothetical question about why no company had previously offered a natural gas-electric hybrid Class 8 truck.

“It requires a specific zero-emission refinement process of fuel, and gutsy engineering and product execution," he stated.

"A traditional manufacturer would have to partner with an oil company, environmental group, electric vehicle engineering firm, a broad spectrum of suppliers and a world-class consulting firm to have figured it out."

Milton was previously CEO of dHybrid Systems, which specialized in natural gas storage, so the use of natural-gas fuel for Nikola's semi truck appears to be an extension of that work.

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The company's claim that it has "achieved 100 percent zero emissions" on its truck would most logically be interpreted as fully battery-electric operation without the turbine generator in operation.

We'll learn more in December.

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