Toyota is going big on fuel cells.

Its latest effort expands on the Mirai sedan by converting semitrucks to hydrogen fuel-cell power.

The company has been testing a fuel-cell powered semi for more than a year at the Port of Long Beach, California, ferrying goods from the Toyota Logistics facility to distribution points headed for factories and other facilities throughout the U.S.

READ THIS: Toyota 'Project Portal' hydrogen fuel-cell heavy-duty semi tractor as proof of concept

The first truck covered 10,000 miles of zero-emissions driving throughout L.A. in a proof-of-concept operation in Toyota's Project Portal.

Now the company has created a second truck that it says will be more commercially viable.

The first truck, "Project Alpha," had a range of 200 miles. Giant hydrogen tanks stood where a sleeper cab would normally go.

Toyota Project Portal 2.0 fuel cell-powered semi-trailer truck

Toyota Project Portal 2.0 fuel cell-powered semi-trailer truck

The new model, "Project Beta," has a range of 300 miles and leaves room for a small sleeper behind the cab without increasing the truck's wheelbase, Toyota says.

Both trucks parallel two fuel-cell stacks from the Toyota Mirai fuel-cell car, to produce 670 horsepower and 1,325 foot-pounds of torque. They use a 12-kwh battery to buffer power.

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The projects are part of Toyota's commitment to eliminate CO2 emissions from its logistics facility in the Port of Long Beach. The company is building a combined power facility to produce hydrogen, water, and a megawatt of electricity at the port from agricultural wastes.

The ports of Los Angeles and Long Beach are a primary focus of California's efforts to clean up its air. About 40 percent of all imports and exports traveling to and from the U.S. come through the ports, creating a concentration of diesel trucks that has been linked to poor health in the area.

California is expanding efforts to replace those trucks with zero-emissions battery-electric and fuel-cell replacements.