ZEBRA electric school bus

When looking at battery tech for (PH)EVs, I came across an interesting experiment converting a school bus into an electric vehicle.

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The battery used here is a ZEBRA (NiNaCl liquid salt) battery pack. These guys paid $53,500 for their 107 kWh ZEBRA battery (in 2003). In volume production, the manufacturer price sheet goes to about $20,000 for the same battery pack. Lots of benefits here over other battery technologies, most notably its cost, it's robustness, safety and its absense of 'rare' metals. Nickel and table salt (NaCl) are the main ingredients.

Technically, school busses (and city busses and most delivery vans) seem to be a great early adopter to become "electrified", not just because of their frequent stops (regenerative braking advantages), and air pollution (noone likes stinking diesels in urban areas), but also because they run short trips (no more than one day at a time).

ZEBRAs seem to have a very bright future in PHEV tech.

Rob

Reply to
Rob Dekker
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If they cycle thousands of times then they are already competitive with liquid hydrocarbon fuel in a lot of applications.

Bret Cahill

Reply to
BretCahill

Not if you count the cost of the batterys properly.

Reply to
Rod Speed

Reply to
John Fields

Reply to
John Fields

Any numbers ?

Yeah. I initially thought that was a problem too. But these things need only 40W to keep them hot (when they do not operate). So that's not a really big deal. Especially since most busses return to a spot where they can be recharged every night.

Reply to
Rob Dekker

Let me try something :

The battery (100kWh) costs $20,000 in volume (price in 2003). Heavily used ZEBRAs can cycle about 1000x before they need to be replaced. That is a capital write-off of about $0.0002 per kWh. That's negligent.

Even if everything goes wrong, battery hardly gets used, and the battery fails one day after the warrenty expires, it's still negligent cost.

That means that the main cost (of 'fuel') is electricity. Assume electricity costs $0.10/kWh. Cycle efficiency (of this ZEBRA bus) is between 78% and 85% (see report). That means a cost (of operating this bus) to about $0.13/kWh.

... Diesel has a heating value average of 38.6 MJ/liter, or 146MJ/gallon. That is 40.7 kWh. Efficiency of diesel engines, mmm, varies widely, but probably in between

30% and 40% (anyone has any better numbers?) in real life use in a large vehicle. That would mean that a diesel engine would release between 12 kWh and 16 kWh of work from one gallon of diesel.

At close to $5/gallon (current diesel retail price in California), this is $0.30-$0.40 per kWh.

...

Net savings : $0.17/kWh. Or in different words : fuel cost saving is certainly more than 56%.

And this is not even considering regenerative braking (typically another 20% of fuel cost saved).

Rob

Reply to
Rob Dekker

YOU made that stupid claim.

YOU get to provide the numbers to support that stupid claim.

THATS how it works.

to be kept hot.

Corse its a problem.

Easy to claim. Hell of a lot harder to actually substantiate that claim.

Wrong again.

Sure, THAT part isnt a problem.

Pity about the rest.

Reply to
Rod Speed

So, kind of emberrasing for an engineer : I made a factor 1000 mistake here :o( Battery cost of $20,000 for 100kWh is $200/kWh. With 1000 charges lifetime, that's $0.20/kWh. That's NOT negligent.

So make that $0.33/kWh. (13cts for electricity + 20cts for capital cost).

So with $0.33/kWh for battery operation, the (fuel) costs are pretty equal (w.r.t. diesel).

That's still the case, so battery operation should still be cost effective. But it's no longer a no-brainer.

My conclusion for now : Cost of batteries has to come down a factor of 2 to be truely competitive (no-brainer sort of thing) w.r.t. diesel.

Reply to
Rob Dekker

Rod, you are now officially a dick-head in my view.

First of, I did not make the claim, Bret did. Apart from the fact that he is right (see side-thread ; IF the battery survives thousands of cycles than it IS already competitive with liquid hydrocarbon fuel in a lot of applications), YOU made the claim that that's NOT true if you count the cost of the batteries properly.

So now it's up to YOU to provide some data to show what you mean with the "count the cost of the batterys properly" and that if you use that data that batteries are NOT competitive with liquid hydrocarbon fuel in ANY application. YOU need to show that because YOU made that claim.

Rob

Reply to
Rob Dekker

Actually that $0.0002/whr.

$20,000 / (1,000 cycles X 100 kilowatt hours) = $0.20/ kWhr.

If it can cycle several thousand times, however, then the price of is only a few cents/kWhr

The cost of diesel increases that much in one year.

That could drop with cheap PV.

In sunny areas the bus could be plastered with PV which would be a significant savings.

Olive oil has 120 cal/serving (actually 120 kcal/15cc) or 8,000 kcal/ liter or 33 kWhr/gallon.

And that's when they are always running at optimum rpm.

So using my battery cost figure diesel is slightly more expensice than battery-grid right now.

Since we know diesel fuel will continue to spiral, it would be foolish not to replace diesel with battery-grid as soon as possible where ever possible.

That'll be true in a couple years anyway.

I think that's 20% recuperation per stop, not overall.

Bret Cahill

Reply to
BretCahill

Rob Dekker wrote

You have always been, and always will be, completely and utterly irrelevant.

What your view might or might not be on anything at all in spades.

You're lying now. YOU made that claim about hydrocarbons.

No it aint, because of the cost of the batterys.

In response to the your stupid claim just above that.

Doesnt need data for something as basic as that.

I never ever said anything like that you stupid liar.

Reply to
Rod Speed

A Jap would at least have the decency to disembowel itself.

Dont make a mess of the carpet.

Dont make a mess of the carpet.

Nope, not when you include the cost of the money used to purchase that battery.

And that aint gunna happen and wouldnt be true even if it did when you include the cost properly.

Reply to
Rod Speed

Nope, because cheap PV aint gunna happen, you watch.

Wrong again. Pity about the cost of the PV and the kids vandalising it.

33 kWhr/gallon.

Different calories, stupid.

Which no bus ever does.

battery-grid right now.

Wrong again.

It hasnt even spiralled yet.

possible where ever possible.

Wrong again. It makes a lot more sense to see if it ever becomes economic.

Nope.

of fuel cost saved).

You're wrong.

Reply to
Rod Speed

Time to retire the slide rule. I understand the new fangled calculators keep track of the decimal point without need of paper and pencil. They can even add and subtract, if my sources are to be believed.

mike

Reply to
m II

I'm not a tweaker. Two orders of magnitude, OK, but _three_ orders of magnitude, well, that's stepping over the line.

My diesel heat content in another post was off by a factor of three, well within my margin of error.

Diesel will go _up_ 20 cents/kW-hr over the next year or so.

The idea that we should wait another year when we _know for sure_ the cost is going up is just plain $%#$@! stupid.

It's some kind of mental blindness going around.

For awhile I toyed with the idea that Big Oil, like Big Tobacco, paid Hollywood to somehow brainwash the public but that would be nearly impossible with farms which are run like a business.

The only explanation is everyone is in some kind of state of denial.

Bret Cahill

Reply to
BretCahill

Reply to
John Fields

Then why did you suggest it?

Care to try another strawman?

I haven't covered this issue yet but I'm guessing it would take up to six years, about the time diesel is $25/gallon, to electrify most basic food crop farms.

In overall costs, grid battery is already competitive or cheaper than diesel in many areas. It would be foolish to replace an old diesel with a new diesel when grid battery will not skyrocket in operating cost.

You don't think intellectual property requires work, both the original concept as well as the development? You think copyright laws and patent rights are a scam?

Maybe Madison screwed up with Art. I, Sec. 8 of the U. S. Constitution?

Or are you so ashamed of your "contributions" you won't share them with anyone?

Maybe you are a loser in your own mind.

If you are a loser in your mind, then you are certainly a loser in my mind.

Bret Cahill

"Only nobodies are ever modest."

-- Goethe

Reply to
BretCahill

in many areas.

We've done the math.

Diesel is already 35 cents / kW hr.

Battery + grid is only 30 cents / kW hr, 27 cents in the TVA area.

Where is this bio diesel being produced?

Is there a pipeline that delivers it anywhere?

Grid battery is all off the shelf.

Bret Cahill

Reply to
BretCahill

So you are not only a dick-head, you are also a retard. Just go back through the tread about who said what.

Reply to
Rob Dekker

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