Why no hybrid trucks yet?

[oil pan 4]

That's only for a 100% efficient system with no friction.
To get a vehicle such as my suburban up a hill, I calculated at a speed of 100fps, I think that was about 70mph a 4% grade doubles the amount of horsepower needed to maintain speed.
Unfortunately interstate commerce isn't as efficient as an elevator.

Soon electric hybrid tractor trailers may become common and I think they are going to have really big packs
Even then I really only expect to see them mostly in the city.

[redpoint5]

Originally Posted by oil pan 4

A hybrid truck with anything over a 10kw pack would likely be a plug in hybrid and would have a starting cost around $10,000 higher than the non hybrid.

Well, let's examine this a bit more...

What would be the ideal pack size to provide enough energy to pull a load up a mountain pass? What is the ideal power output of the electric motor to give the needed acceleration given an undersized ICE engine? What would be the ideal pack size to soak up the enormous amounts of power that regen would create?

Perhaps 20 kWh would be the ideal battery size? That's roughly the size of the gen I EVs such as the Leaf, Spark, and i3. The i3 has a 170 horsepower electric motor, which should be plenty for a hybrid truck.

Battery cost is somewhere around $190 per kWh, so a 20 kWh pack would be $3,800. If the truck could run on EV alone, which it should if it had a 170 horsepower motor, it might get 50 miles of EV range.

Who knows how much the other hybrid components would add to the cost? From what I'm finding, hybrid technology adds about a 10% premium to a vehicle.

It seems to me that a 20 kWh battery and 170 HP motor might add $6,000 to the price of the truck, but that doesn't factor in the cost savings of a smaller engine and transmission, and no driveline to the rear.

Based on my estimate of fuel savings above, it would take somewhere around 12 years to recover the extra cost, but that doesn't factor in the fact that trips under 50 miles could be completed on EV power alone.

I'm just spitballing here, so what are your thoughts on battery size, motor size, and cost?

[RedDevil]

Originally Posted by oil pan 4

That's only for a 100% efficient system with no friction.
To get a vehicle such as my suburban up a hill, I calculated at a speed of 100fps, I think that was about 70mph a 4% grade doubles the amount of horsepower needed to maintain speed.
Unfortunately interstate commerce isn't as efficient as an elevator.

Soon electric hybrid tractor trailers may become common and I think they are going to have really big packs
Even then I really only expect to see them mostly in the city.

Battery to wheels is typically better than 80% efficient for EV's.

There's been research if one could gain back electricity from elevators by making them go up empty and down fully loaded. But it isn't, the sheer weight of the cabin, cables and counterweight and the friction over the wheels and motor cause losses any way.

An EV of hybrid can harvest energy doing down...
Electrified interstate commerce would be far more efficient than an elevator.

[fusion210]

I'm sure they're coming. It might not count by your definition but the Ram 1500 now comes with a standard v6 mild hybrid system. The hybrid system is also available with the 5.7l hemi.

We're supposed to be getting a plug in hybrid F-150 for the 2020 model year.
2020 Ford F-150 Plug-In Hybrid: Spied - PickupTrucks.com News

[Angel And The Wolf]

Originally Posted by RedDevil

There's been research if one could gain back electricity from elevators by making them go up empty and down fully loaded. But it isn't, the sheer weight of the cabin, cables and counterweight and the friction over the wheels and motor cause losses any way.

Properly counter weighted, an empty elevator can ascend with little use of electricity. However, add passengers, and going up needs more energy or more counterweights. If weights could be connected and disconnected as needed, every passenger load could be equally counter weighted. Probably the most efficient counterweights would be water gravity piped from a source above the top floor, and dumped for up trips. No need to return the water to the top.
Possibly, flowing water could run a water turbine to lift the elevator through reduction gears, and the source need not be above the top floor.

[jamesqf]

Originally Posted by RedDevil

60 kWh is the energy needed to lift a load of 30 metric tonnes up 720 meter (about 2400 foot).
That would in itself be enough to clear most hills...

Not around here :-)

[redpoint5]

Originally Posted by Angel And The Wolf

Properly counter weighted, an empty elevator can ascend with little use of electricity. However, add passengers, and going up needs more energy or more counterweights. If weights could be connected and disconnected as needed, every passenger load could be equally counter weighted. Probably the most efficient counterweights would be water gravity piped from a source above the top floor, and dumped for up trips. No need to return the water to the top.
Possibly, flowing water could run a water turbine to lift the elevator through reduction gears, and the source need not be above the top floor.

I built a pulley system in a tree I used to sleep in during summer nights in my youth. Attached to one end of the rope was a burlap sack of rocks nearly my weight. I climbed the tree, connected to the rope, and lowered myself to the ground. Then I attached the rope to a hook I buried in the ground. Going back up required very little pulling effort.

Solid weights would probably most efficient for counterweighting an elevator since they can quickly be attached or detached and involve no pumping losses. That said, multiple floors complicates things, and moving people up and down floors doesn't cost much in energy. The added efficiency of dynamic counterweights would never offset the cost of the system.

[cajunfj40]

Unfortunately, I think it boils down to "Corvettes always have more horsepower than Camaros", at least in the consumer market.

If you take a look at the GM Two-Mode Hybrid system from 2008-??, the powertrain was quite a bit more capable than what it was constrained to.

The 2ML70 transmission was, roughly speaking, a 4L80E with two Remy HVH-250 cores in it. Those cores can do 80hp/147lb-ft continuous and 110hp/240lb-ft peak each at 350V - more with higher cooling fluid flow and voltage. Add that to the 332hp/367lb-ft 6.0L V8 it has, and you should have a blistering 672hp/847lb-ft available on full-combined-power takeoff, with at least 160hp/294lb-ft available in all-electric mode - enough to drive a modest load at freeway speeds.

As delivered and tested, you got a lower payload and a lower tow rating than the conventional 6.2L gas-only version, it accelerated slower, and electric-only was only available up to 32mph flat, 10mph uphill towing. As redpoint5 noted, GM only claimed a net 379hp - lower than the big 6.2 V8.

My guess is, much like how they substituted a constricted intake manifold on the V8 in the Camaro so it performed worse than the *identical* engine in the much pricier Corvette, they intentionally detuned the hybrid so it didn't beat the big V8. That also allowed them to go with a smaller battery pack, to keep the cost down. Have to keep the profit margins in line, so they mostly built them as fully optioned high-end vehicles. So they got some good ad copy from "Hybrid!" and "20mpg truck!", got some EPA fleet fuel economy benefits, and got to test out a bigger full hybrid system. I never really heard anything "bad" about them - unlike the variable displacement tech of the same era - and the 4x4 Tahoe Hybrids still go for over $10K on the used market.

Since then, we've been seeing steady improvements in power and payload ratings in fullsize trucks - but mpg has been relatively constant, or slightly improving, with a few "ringer" high-mpg offerings on stripped-down 2WD models. Engine sizes have also been dropping, without a loss in power or payload. So efficiency gains are still being made - at least per EPA tests. As fusion210 notes, there are mild hybrid options on most consumer trucks, either now or soon, and auto start/stop has been steadily improving.

I think we'll continue to see steady incremental improvement, and the manufacturers pretty much all have the tech available to spin up a plug-in hybrid relatively quickly if the market opens up for it. It will still need to "not beat the big engine" and not lose any profit margin, though.

[S Keith]

EDIT: I didn't read Cajun's post before I posted this. His is better.

Originally Posted by redpoint5

Maybe that was a decent attempt for 2009, but it's still lousy. It uses NiMh batteries. "On its own, the V8 is rated at 332 horsepower and 367 pound-feet of torque. GM engineers say that combined output with the electric motors is 379 hp." That's just a 47 HP boost, or 14% of the rated engine power. They didn't decrease the engine size at all. It still has a V8 and a driveline.

When I mean hybrid, I mean something capable of a 100hp or more boost of EV power, ability to regen most of the energy rather than use brakes, and tool around at low speed on battery only. Perhaps something with a 20kWh battery.

IIRC GM 2-mode hybrid motors are capable of 160hp combined (think Prius MG1 and MG2) and are integrated into the transmission.

Combined hp ratings are given at the peak power output (typically near redline) and are slave to design limitations. At that rpm, you don't get the full oomph of the EV motors.

If looking at economy boost, they were very good implementations, NiMH or not. The big downside is relatively poor battery management. Even so, they frequently push 200K miles before their batteries crap out. Up until about a year ago, one could get the 40 module pack (big as a GS450h) for as little as 2800 installed. Unfortunately, that's up about 1K.

Using the Tahoe Hybrid as an example, it's 21 mpg rating improvement over the non-hybrid at 15mpg is massive and about as good as one could expect.

For the Tahoe/Yukon/Escalade there were only 22,000 sold across all years. The Silverado/Sierra hybrid sold a total of 6,300 across all years.

The answer to your question is that there is no market for hybrid trucks/SUVs. That's why GM stopped making them, and everybody took a lesson from their experience and stayed out of the US market.

[oil pan 4]

It's still going to take a pickup around 22 to 30 kw to maintain highway speed. I would say closer to 3kw because my leaf uses about 20kw to maintain 74mph.
So there is some way to recover energy used to over come air drag?
I would love to see this.

I said $10,000 because the plug in hybrid Hyundai sonata is about $10,000 more than the gas only version, has a 9.8kwh pack and only a 40 or 50hp electric motor.
So I think a $10,000 price increase for a hybrid truck with a 10kwh pack is very realistic.