Semi-Trailer Trucks Test Converting Into Plug-In Hybrids
1 48Long-time Slashdot reader necro81 writes: There are several companies, such as Tesla, trying to make semi trucks fully electric. The capital cost for such a truck, and the MW-scale infrastructure to recharge it, may be a hard sell for some operators. [IEEE Spectrum notes that's a charging infrastructure "that most freight corridors do not yet reliably provide."] But some companies are instead adding batteries and an electric motor to the semi-trailers that trucks haul behind them.
"The Nivalis Powered Trailer Kit centers on an electric axle [rated at 50 kilowatts-peak]... capable of both propulsion assistance and regenerative braking. It draws on a 60-kilowatt-hour, 400-volt lithium-ion battery pack charged from three sources: the axle itself during braking and deceleration, a full-rooftop array of photovoltaic panels generating up to 3.7 kilowatts-peak, and a 32-amp, three-phase AC grid connection available during parking stops."
This approach is more akin to a plug-in hybrid: the truck may still be diesel-powered, but the electric assist from the trailer allows the truck to run more efficiently. Replacing diesel with kWh can save operators money while also reducing emissions. This incremental approach may be more accessible and less capital-intensive than replacing the truck itself.
From the article: The driver's only window into the system is a small display readable from the cab's side mirror that shows the system status and battery charge level. Nothing about the trailer's handling or licensing requirements changes. The partners project savings of up to 7,000 liters of diesel per trailer per year, which is enough to keep about 19 tonnes of carbon dioxide out of the air...
Trailer Dynamics, an Aachen-based company, has conducted field tests with BMW Logistics, DB Schenker, Duvenbeck, and Volkswagen Konzernlogistik, reporting average fuel savings of around 40% for diesel tractor combinations, substantially higher than the up to 18% reduction implied by the Nivalis projection... Trailer Dynamics prices its system between €145,000 and €195,000 and targets a payback period of no more than five years. Nivalis targets five to six years at current costs.
1 comments
This seems dubious... (Score: 5, Insightful)
by dgatwood ( 11270 ) on Monday July 13, 2026 @02:36AM (#66235542)
This seems dubious at multiple levels.
Solar panels: The roof of a trailer is about 450 square feet. In the northeastern U.S., you would average only 3.5 hours of full sun, so you'd get only a little over 13 kW per day.
Tesla semis are pretty efficient, and they use about 1.7 kWh per mile. So in an entire day, covering the entire roof of a trailer with solar panels would add a whopping 7 miles of range, or 15 minutes of extra driving — the equivalent of plugging into a Tesla Megacharger for maybe 30 seconds or so.
Let's optimistically assume that the vehicle can carry 48,000 pounds. If those panels occupy the full roof area, then at about 3 pounds of weight per square foot, those solar panels would weigh 1500 pounds, or about 3% of your cargo, all to reduce your fuel usage by as little as 1% if you're doing long haul at 65 MPH. And that weight number may be wildly optimistic. Trailers like that aren't designed to have weight on the roof, and would require additional structure to hold that extra weight. The real losses could be significantly higher. Unless you're driving less than a couple of hundred miles in a day, the solar panels won't break even. And if you're driving less than a couple of hundred miles per day, there's no reason you can't go electric.
Battery and motor on the trailer: I would expect most trucks to be used primarily for either short-haul or long-haul purposes, not both. If you're doing long-haul, you'd probably be better off with an actual hybrid tractor so that you get the benefit no matter whose trailer you're hauling. If you're doing short-haul, there's likely no reason not to go full electric.
I just don't get it.