Lightning (Hydraulic Hybrid) Strikes Denver

[Fledermaus]

Since announcing the LH4 earlier this year, CEO Dan Johnson and his crew of 14 employees have been working almost non-stop to get a concept car ready for this week's Denver Auto Show. It delivered the car to the show just hours before the doors opened, and what they rolled inside is a not-too-shabby-looking facsimile of the car Johnson hopes to see rolling out of a factory by 2011.

"We have a very hard-working crew who have given everything they've got to make some time," Johnson said, in a statement, of the effort that went into building the prototype. "Yes, it was tight - really tight. But we are very pleased with the car and with the response we have received from the people at the show."

Johnson claims the LH4 will get 100 mpg and do zero to 60 in under six seconds. If all goes according to plan, the car will compete in the Progressive Automotive X Prize.

Johnson modeled the LH4 after the '63 Stingray Corvette he restored in high school. It features a 90-horsepower diesel engine plucked from a Volkswagen; it's mated to a 150 horsepower Rexroth hydraulic hybrid system - technology that has so far been limited to delivery trucks. Such systems ditch batteries in favor of hydraulic power, and Lightning says it offers better fuel economy and energy regeneration than conventional gas-electric systems.

http://blog.wired.com/cars/2009/04/lightning-hybri.html

[baldguy]

1. $40K and ugly wont help the US auto industry.

[drm604]

3. But it doesn't have to look like that.

The drive system is the important part, and that could be placed in any kind of body that can accommodate it. It doesn't have to look like the concept car.

Hopefully, the price would come down with mass production.

[drm604]

2. Interesting concept.

I'm no expert but it seems like a hydraulic energy storage system should be more durable and possibly less expensive than batteries. It also seems like there would be less energy loss during storage and release of the energy. Maybe someone more knowledgeable than me can confirm my hunches.

[Fledermaus]

4. Electric or hydraulic? Hydraulic Hybrid - The Most Efficient Lowest Cost Hybrids

Electric and hydraulic transmissions both offer power management, energy storage and flexibility. It is even possible to eliminate the mechanical drive train completely and have an in-wheel motor installed in the hub of each wheel.

These series systems are only feasible if all the transmission components have a high efficiency, also at part load and start up conditions. Furthermore the power density, especially for the wheel motors is a challenge.

Compared with electric series hybrids the Hydrid has an extreme high regenerative efficiency, more than double than that of electric hybrids. Furthermore challenges connected to hydraulic hybrids like weight, cost and packaging/NVH can now be met due to the new enabling floating cup technology.
http://www.innas.com/HD_EorH.html

Hydraulic Hybrid - The Most Efficient Lowest Cost Hybrids

World’s First Full Series Hydraulic Hybrid Delivery Vehicle Prototyped in a UPS “Package Car.”
Through the use of innovative hydraulic hybrid technology EPA and its industry partners have been able to create the most efficient and cost-effective powertrain technology in the world. EPA has been able to improve city fuel economy of a UPS package car by 70% and reduce CO2 greenhouse gas emissions by 40%. The unique energy recovery technology used while braking reduces brake wear by 75%, increasing the net savings substantially.

A fleet owner operating one of these high efficiency vehicles would save up to 1,000 gallons of fuel each year.

What is even more astounding is that the additional cost for this technology manufactured in high volume has the potential to be less than 15% of the price of the base vehicle. At current fuel prices, this technology will pay for itself in two to three years.

The net lifetime savings over this vehicle's typical 20 year lifespan would be over $50,000.

Hydraulic Hybrid Vehicles (HHVs) rely on proven innovative technology which can be applied to light duty work trucks, SUVs and heavy duty urban vehicles such as city transit buses and garbage trucks.
http://www.epa.gov/otaq/technology/420f06043.htm

[drm604]

5. Cool!

So why the hell have we been mucking around with electric hybrids?

The only advantage I can see from an electric hybrid is plug in capability, but surely this could also be done with hydraulics by using an electric pump to pressurize the hydraulics.

[exboyfil]

6. Electric Hybrid an intermediate step to all electric

I think part of the issue is that folks view electric cars as "greener" than alternatives because it is easier to generate electricity using "green" technologies (solar and wind). The problem then becomes justifying green electric cars using the current cost of electrictiy (using dirty coal) while not considering the "green" life cycle costs of producing the same electric power with "green" technologies which internalize more of the externalities.

I like the idea of hydraulic hybrids (I am in the hydraulics industry), but I am uneasy with a bunch of passenger cars and fleet vehicles driving around with highly pressurized accumulators. It appears a great deal of good work has been done to make these accumulators safer though.

[drm604]

7. So there's a safety issue.

I hadn't considered that. Assuming that issue were resolved you could have non-hybrid hydraulics. The hydraulics are simply a replacement for battery storage after all. You could use an electric pump to pressurize the hydraulics instead of charging a battery. That would be equivalent to all electric.

That said, the problem I see with all electric is that there are millions of car owners who have no easy way to plug in their car each night. For example, if you live in a row house in an urban environment you park at the curb every night and not necessarily even in front of your house. There would be huge infrastructure requirements needed to resolve this. My personal opinion is that the answer lies in some kind of hybrids that run on some sort of carbon neutral liquid fuel dispensed the way gasoline is dispensed now.

Of course a real answer needs to include greatly increased public transportation.

[zipplewrath]

8. Safety is relative

Let us begin by recognizing that we already have "millions of cars" driving around filled with gasoline, so a pressurize accumulator is only a "different" kind of safety hazard. Fire departments are already concerned about the PHEV and their large electric cables when having to cut into accident vehicles to extract people. So again, mostly this is a case of one danger vs. another. And all cars have coil springs which have a tremendous amount of energy stored in them. If you've ever replaced one, they'll scare the hell out of you.

If there is a "downside" to hydraulics, it is that the technology is probably about as mature as it is going to get, where as battery technology probably has nowhere to go but up. So if they are currently "comparable" or even if hydraulics have some advantage, it is probably not going to last long. Strangely, an advantage for them could be that they could be "recharged" rather quickly in some commercial setting (gas station).

[drm604]

9. Quick recharging is a good point that I hadn't considered.

That could be the solution to the all electric recharge problem that I pointed out.

I'm hoping that exboyfil responds to your points about hydraulics, since he works in the industry.

[Fledermaus]

13. I think an electric hydraulic hybrid would be cool

Actually the energy storage medium is inert nitrogen. The inside the accumulator hydraulic fluid press against a rubber bladder with the nitrogen on the other side. Nothing els can provide such rapid rate of charge and discharged endlessly. Its the best for stop and go traffic. For current regenerative braking systems hydraulic has 70% energy efficiency. Electric has what...10%

Better regenerative braking would give electric cars much better range particularly in city driving.

[Fledermaus]

10. Gosh, any high density energy storage device can be dangerous, batteries are no exception either.

I'm not saying any one is better than another its just a fact.

Laptop PC explodes violently
http://www.youtube.com/watch?v=tC0UWIYswKI&feature=related

PC Pitstop: Laptop Battery Fire
http://www.youtube.com/watch?v=WeWq6rWzChw

[drm604]

11. There are different levels of risk.

I don't know the risk levels of hydraulics versus batteries, but the issue can't be dismissed simply by saying that both can be dangerous. The question is, is one more dangerous than the other and if so, how much more dangerous?

[Fledermaus]

12. Safe Enough!

UPS First in Industry to Purchase Hydraulic Hybrid Vehicles
http://www.youtube.com/watch?v=cKLcPWRnTbs

BMW 530i Digital Displacement Hybrid
http://www.youtube.com/watch?v=CJw5AvvxBqg