While battery-powered semi trucks remains years away for many prominent makers, the German tech company Siemens is experimenting with a well-known source of electric power delivery to make a different kind of electric semi.
Much like electric trams or streetcars used by public transit agencies for more than 100 years, the method employs a catenary system to provide power drawn from overhead wires.
An active pantograph on top of each truck stays in contact with the overhead line, continually charging an onboard hybrid system as long as the semi runs under the wires.
Siemens set up its first pilot "eHighway" utilizing the system in Sweden back in 2016, and now California's South Coast Air Quality Management District has picked up the idea as well.
Siemens and SCAQMD will test the system on a 1-mile-long pilot stretch of roadway between Los Angeles and Long Beach.
When the trucks aren't running on electricity, their hybrid powertrain reverts to its combustion engine, using either conventional diesel fuel or compressed natural gas.
The engine switches on automatically when the trucks disconnect from the catenary system to pass another vehicle or change lanes, or simply when the system doesn't need further charging.
It also allows the trucks to leave the lane equipped with the overhead wires.
The growth in freight traffic may contribute to a doubling of global CO2 emissions from today's levels by 2050, according to Andreas Thon, Siemens’ head of Turnkey Projects and Electrification, North America.
Siemens' system could prove useful in highly congested areas where charging-station infrastructure is lacking.
The Port of Los Angeles continues to experiment with multiple initiatives to reduce emissions from the area.
The Clean Air Action Plan developed by the Port calls for harmful emission levels to fall consistently over a 12-year period.
Another such experiment tests a different zero-emission powertrain altogether: hydrogen fuel cells for large trucks.
Notably, Toyota introduced its Project Portal semi truck with the Port and California Air Resources Board (CARB) this past April.
The semi truck utilizes a pair of Toyota Mirai fuel-cell stacks and a 12-kilowatt-hour battery to produce 670 horsepower and 1,325 pound-feet of torque.
Toyota began carrying out feasibility tests this past summer with the semi truck, while Siemens' eHighway is now operational in California.
Siemens' technology will help SCAQMD understand potential avenues to further decrease emissions in the near future.
Residents of the port area have long pushed for reductions in the diesel exhaust emissions from both the trains and the thousands of trucks that haul freight in and out of the busy port, one of the largest on the West Coast.