Bosch Reveals Electric Semi Trailer: Uses Regen To Recoup Energy


Bosch is electrifying semitrailers, pushing electromobility into even today’s semi trucks

Later this year, at the IAA Commercial Vehicles in Hannover, Bosch will be presenting an electrified axle that can easily be integrated into semitrailers.

The idea is to utilize the semitrailer’s axles, which are now simply rolling freely and unused, by integrating an electrical machine. In turn, this can then produce electricity during braking, and feed it into the trailer’s power units. According to Bosch, when used with a refrigerated trailer, this solution can result in savings of as much as 10,000 euros a year with as much as 9,000 liters of diesel fuel saved per year.

Furthermore, another positive effect of this solution is that the trucker can use an electrical start and acceleration boost function, which, in turn, helps save even more. Naturally, this provides a hefty reduction of CO2 emissions as well. Furthermore, when used with delivery trucks set for the urban environments, when heading to supermarkets, these electric cooling refrigeration units are much quieter than their diesel-powered counterparts. This allows for early morning or late night delivery to be performed, all without too much disturbance for the neighborhood.

“Bosch is making trucks’ rear axles electric and smart. Our electrification solution for trucks makes economic sense and shows how electromobility can work even in today’s trucks.” Dr. Markus Heyn, member of the Robert Bosch GmbH board of management

The German industrial giant is also eyeing another step toward automated trailer parking on logistics companies’ parking lots thanks in part to the axle electrification. With a powertrain added to an axle, the need for a tractor to shunt the trailer around the parking lot is negated, saving both costs and time. While the tech is currently offered for new trailers or as part of a retrofit option, the possibilities and demand is huge. According to Automotive World, there are roughly a quarter of a million trailers with a gross vehicle weight of more than 10 metric tons are newly registered every year in Europe alone. For those, one in five comes with a refrigeration unit, making for an impressive amount of vehicles that could benefit from such a solution.

Source: Automotive World

Categories: Trucks


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42 Comments on "Bosch Reveals Electric Semi Trailer: Uses Regen To Recoup Energy"

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This makes sense, the average big rigs gets less than 5 mpg loaded.

Since the SCR was added in 2010, mileage is much higher today, probably 50% in many cases.

What?? The new emissions have killed fuel economy, and made the trucks less reliable.

The point being millions of big rigs are not getting 10+ mpg, this could help.

Even out dump trucks do better then 5 mpg, and they spend part of their life on site, and dumping. More efficient highway trucks are closer to 6-9MPG today, 7 being a number I hear often..

So 6 mpg is fine?
How about we get millions going 12+ mpg.

Average on new semis is around 8, with a national fleet average of 6.5 mpg.

And they are pushing for 10 mpg, though electrics will probably give 20+ MPGe.

Most new trucks under load are close to consistent 8 mpg or better, even back to 2005 or so was in the 6.5 range. Running empty I get close to 12

Bunny, when you say empty, I assume you mean trailer, but no payload? Or bobtail?

When I say empty, that would be with a trailer with no load. Otherwise I would say bobtail meaning with no trailer.

But in truckspeak shorthand

“MT” means “empty trailer”
“BOX” means “dry van trailer”
“CAN” means “container”
“Skateboard” means flat bed trailer
“Parking Lot” means auto hauler truck

“Zipper” means the dashed line in the middle of the road that divides the lanes.


Thanks for the lesson in lingo! 🙂

Highway, yes. Urban delivery cycles they are much, much lower mpg, depending on the route. Where I am it’s hilly and congested, and I’m surprised there’s not already a market for electrified delivery trucks and vans. This tech doesn’t help enough on highway routes to make it a good ROI, but could be very economical on urban routes such as grocery delivery.

Two other benefits are noise. Noise is huge, we used to have to spend a lot on upgraded exhaust for trailers and trucks due to neighborhood complaints for routes that all started from 4am to 6am. The savings on brake wear would also be substantial.

Yeah, those jake brakes are LOUD. Thanx for adding mufflers to that.

I saw that BMW has ceramic brakes now. In the back of my mind,I keep wondering if electric Semis should go that route? I think that they would last forever, due to combining with regen.

No word on the battery size…

Because this isn’t a product. This is a demonstration of what you could build using the Bosch eAxle. They are not going to start building trailers or cars or anything like that. They make building blocks others can use.

To shunt it around, you’d still need some front wheels, unless they are only talking about the tandem trailers.

Adding some simple retractable running gear shouldn’t be much of a challenge I guess? These would only be for manoeuvring parking lots at walking speed, not for going on highways…

That is a good idea,

This has been around for years

good find!

Bunny; what do you think?

I think for companies like SYSCO it’s a good idea, I know Thermo King has been working on prototype solar reefer units that they have gotten to work pretty well for produce type loads (34 -38 degrees) but they haven’t gotten the tech down to frozen food / ice cream levels. The regen for reefer, it’d be great to keep batteries charged for the reefer because even losing a produce load is like 100K

I’m just going to mention something else is passing, more so with regular dry vans, not reefers, trailers take a huge amount of abuse when they sit at customers, shippers, rail yards, just drop lots in general, large companies that have tens of thousands of trailers
Some trailers might sit in a parking lot for 10 months and nobody has used it, it’s very common for trailers to have their inspection stickers out of date, all that being said, companies don’t like expensive options on trailers, don’t like extra maintenance on trailers.

I think for reefers though, good idea

Here’s a question – what’s the deal with refrigerated trailers riding on flatbed train cars? Are they always empty, or running on some sort of reserve?

Reefer trailers normally have 25 to 40 gallon diesel fuel tanks so each trailer is self contained.

With reefer containers it really varies because some get plugged in etc

huh. Surprised they are not using aerogel on those.


Glad Bosch is waking up. George Bower and I discussed the potential for trailer regen several months ago here at IEVs.

However, isn’t it rare that the truck owners actually own trailers and if so, why not just add this to one of the semi’s axels?

“why not just add this to one of the semi’s axels?”
It’s out there I think hyperion makes it.
just google it

Large companies that have their own distribution network will want this. At least at first.

You still have to brake the trailer axles too, either regenerate or let it heat up the brakes. So with an electric trailer and electric semi, you get double the benefit (approx).

AIUI with the jackknifing protection on the Tesla Semi, they can avoid the need for trailer breaking most of the time…

Bacardi said:

“However, isn’t it rare that the truck owners actually own trailers and if so, why not just add this to one of the semi’s axels?”

Exactly, thanks.

Doesn’t really matter who owns the trailers. The important point here is that there are about 6 trailers around for each tractor, so nobody wants to spend money on ~6 trailer upgrades instead of just one tractor upgrade.

If Bunny says this might make sense for reefers I certainly won’t argue with him; he’s our forum expert on the trucking industry and I value his contributions. But aside from reefers, I would be surprised to see many semi trailers with this sort of equipment installed. It makes no sense, economically.

Yeah, but if you can simply replace an axle or two and plug it into an EV tractor, then it would be easy to simply re-fit the trailors. I think the flatbeds, etc are probably cheaper to buy new with the axle,but it is really a matter of how low they can get that costs down.

That’s true on non reefers ( dry vans) most companies won’t even pay for air ride suspensions or tire self inflation systems, they keep the cost of the trailer as cheap as possible not only upfront investment but also in maintenance costs.

It’s funny to see Bosch doing what I’ve suggested for sometime. The ability to accelerate, along with stopping without jackknifing and recapturing some of the energy is huge.

I used to work for a bus company and we had some Volvo hybrids. The idea was simple, the retarder was replaced by a motor generator and would regen on braking and use pure EV until 10mph. On our older DAF buses we used to get 5 to 7mpg but these hybrid buses would give a minimum of 9mpg. I held a bus license and would occasionally help out by covering late shifts, if you had the time to make the most of EV mode you could get them to drive in EV for several miles up to 20mph and attain up to 14mpg.

Nice. The big thing is….is their an industry standard for hooking up that regen trailer to the upcoming EV tractors?

The way they describe it, I think it’s supposed to be a self-contained system.

That’s how I read it, too.

I’m sure we will continue to see articles suggesting that putting an EV drivetrain into a semi trailer makes sense.

But it never will. Trucking fleets typically have about six trailers for every tractor. Trailers need to be as cheap as possible, all else being equal. It makes no sense at all for a trucking fleet to pay for and install six EV drivertrains for trailers, instead of just one for the tractor. Any upgrade to the drivetrain or powertrain needs to be in the tractor, not the trailer.

It truly is about costs. In particular the large for hire companies you almost have to experience it to see just how far these guys will go to cut costs and still stay compliant with the DOT and not lose their drivers over cost cutting policies. I was still driving for SNI when the economy blew up back in 2008 and I mean they even went down to 1” duct tape as driver supplies because somebody in Green Bay figured it was cheaper than normal 2” duct tape, sounds silly but even that kind of stuff multiplied by 13,000 drivers , anything you do becomes real money because of the shear volume of whatever it is. They used to say if you as a driver can save just one gallon a day of fuel (driving habits, idling, etc. ) it’s equal a million dollars a year savings across the fleet in expense, thus the trailer skirts, wheel covers, idle sensors ( shuts the truck off after 4 minutes) governed down to 63 or 60 mph always chasing even one tenth of a gallon of an improvement on your mpg. They became almost OCD on micro managing their drivers and truly… Read more »