The eHighway works with hybrid diesel electric freight trucks equipped with retractable devices that collect electric current from overhead lines.
Until the day that EV batteries can provide a range comparable to that of legacy internal combustion vehicles, some sort of dynamic charging system, which can power vehicles while underway, would be very handy indeed. Siemens is developing a simple and obvious solution – using overhead wires. The company announced its new concept, which it calls the ‘eHighway of the Future,’ at this week’s Electric Vehicle Symposium in Los Angeles.
A Stanford University research team is currently working on a more futuristic solution, wireless dynamic charging, which uses inductive charging coils embedded in the roadway, but it isn’t likely to be ready for deployment for several years – by which time improvements in battery capacity may have made it largely unnecessary. Siemens’ system relies on a mature technology that’s been in use for decades on rail and trolleybus lines around the world.
The eHighway of the Future works with hybrid diesel electric freight trucks equipped with retractable devices (sometimes called “pantographs”) that collect electric current from overhead lines. The trucks automatically switch to electric mode when they detect and attach to the overhead lines, and switch back to diesel when they leave the lines. Siemens is currently testing the system in Germany, and pilot projects are planned for the ports of Los Angeles and Long Beach, which have long been interested in zero-emissions freight vehicles, and already use some EVs for short-haul drayage.
While some see dynamic charging as a transitional technology designed to overcome the limitations of today’s batteries, in some applications it could be an optimal solution. A tractor used to transport containers over short distances in and around a port facility, if it were powered by overhead wires, would never need to stop to charge, and could get by with a small battery pack, or none at all.