Did you consider the Honda Clarity before your Prius Prime?

No, you said

And your "model" presumes the same, which is why your results are garbage.

May I recommend a $2 calculator. You need one.

SURPRISE ! We are discussing EVs here, specifically the energy consumption penalty from adding range.

I'm pretty much done here, you have bored me with your stubborn unwillingness to accept simple facts. I do admit to some amazement though that I show you fuel economy data from comparison cars that are no where near what your "model" would imply and you somehow ignore what is staring you in the face.

 

When looking at the kinetic and potential energy of an object in space, there is conservation of energy. At perigee, the altitude is minimum and velocity maximum. At apergee, minimum velocity and maximum altitude. The total energy remains the same minus a very small drag from the nearly perfect vacuum of space.

In your case, deceleration heats the brake pads. The energy is transferred to heat but there is a loss of entropy. But these are trivial effects any high school physics would cover.

In a perfect machine, the energy accelerating a mass can be recovered slowing it. That is how Muther Nature works.

It was in differential equations a long, long time ago I learned the math term, ‘conservative field’ that describes what happens in some cases. Non conservative fields are not reversible.

Bob Wilson

 

I know way more about orbital mechanics than I probably should, but we were talking about automobile mechanics (and electrics), not frictionless space.

 

PriusChat thread drift is a thing of wonder and horror.

Bob Wilson

 

Believe it or not next on the agenda is a discussion about the advantages of electrically powered spacecraft vs. chemically powered spacecraft for deep space missions.

Actually there really is a method of electric propulsion for spacecraft, but please don't ask me about it here just Google it

 

Jay can huff and puff until he is purple that adding miles of range is going to require huge batteries to offset the increased energy consumption per mile from the added mass, but the data speaks for itself: An EV with 95 miles more range has BETTER fuel economy than an otherwise very similar if not identical car with a smaller battery.

 

I just tried to get a price for 1 kg of hydrogen purchased at the Anaheim station. A young lady answered the phone, and then had to take my phone number and then told me that they would have somebody call me with the pricing! RIDICULOUS!! They just want to milk me for my info to promote their product. What a crock! I'm now sitting on the edge of my seat, waiting for their callback, like some little teeny bopper in love!!

Posted via the PriusChat mobile app.
AChoiredTaste.com

 

Those cars are only 194 pounds different in weight, and probably have other differences in the propulsion system.

Apples-to-apples, adding a thousand pounds of dead weight for 100% of your driving will substantially reduce your energy efficiency.

 

Hydrogen Production Cost Analysis | Hydrogen and Fuel Cells | NREL

 

Mr. Jay,
Someone had asked me to get the current price of fuel at the Anaheim hydrogen station; didn't have time (for now) to drive there (not really that close to my house), so I called. I posted the results on the post to which you replied. I'm holding my breath til they call me!

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AChoiredTaste.com

 

I found it interesting that hydrogen stations have two types of nozzles, H35 and H70. The only difference is the delivery pressure, 350 bar (approx 5,000 psi) for trucks and buses, 700 bar (approx 10,000 psi) for cars. The nozzles are slightly different, H35 vehicles cannot use the H70 nozzle, however apparently cars can use the H35 nozzle, which they would do in case the H70 pump is not operating for some reason. However then they will only be able to fill up their tank halfway, and if they are already at half a tank or more, trying to use the H35 pump will do nothing.

I would guess the price is the same, however H70 is run through additional compression which presumably costs the station something in electricity, maybe they pass that cost on via slightly higher price for H70. When they call you back see if you can get the price for both. If they ask you why you need both prices, tell them you haven't decided if you will be driving your car or your bus today

 

Oh it will definitely be the BUS!

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AChoiredTaste.com

 

The relative weight of the battery pack or curb weights would be useful. Let me offer my BMW i3-REx as another example:

Adding the REx, about my weight, does the following:

• 10.9% increase in weight - 264 / 2635
• 11.1% decrease in EV range - (81 - 72) / 81
• 85.2% increase in range - (150 - 81) / 81
• The BEV version uses a heat-pump versus resistance heating of the Rex.

Later, BMW increased the capacity of the battery pack, ~50%, with these curb weights:

• 2961 lbs - BMW i3
• 3234 lbs - BMW i3-REx
  • 273 lbs REx

Bob Wilson

 

Granted, but this is the type of "dead weight" that Jay talks about. I am specifically referring to extra battery weight. The distinction is important because the acceleration losses are mitigated, perhaps even improved upon compared to an otherwise identical car with a smaller battery.

What effect did a larger battery have on fuel economy in the i3 models ?

Last year Tesla published a first look at the Roadster 2.0. TWO HUNDRED kWh battery that weighs 863 Kg, in a 2+2 car. 620 miles range at highway driving, 3.1 miles a kWh (104 MPGE). I'll be the first to guess that the Roadster 2.0 has a more efficient motor and a lower CdA than the Model 'S', but that is the key point here: whatever mass losses the heavier battery adds to the car can be offset elsewhere. This is possible because the extra mass related losses are no where near his prediction. Jay's "model" of horrible fuel economy in extra-super long range EVs is not born out in practice.

The Tesla Model 3 LR has a 324 mile range. Another 200 lbs of battery weight will bring the range to well over 400 miles and I'm willing to bet that the current 130 combined MPGe will at most drop a couple of percent. Quick arithmetic says that an extra 100 Kg of mass will increase rolling losses 2.5 Wh/km. Compare that to the ~ 25-30% PV to H2 car wheels efficiency.

Incidentally, another data point will show up in the next couple of months when the Model 3 SR comes to market. It has ~ 25 kWh smaller battery, ~ 100 miles less range, and weighs some 300 lbs less. I expect a ~ 2% better MPGe compared to the LR model.

 

Why the negativity to this new high tech means of propulsion?
(and arguing a few MPGe between models. Such a minor thing. Maybe they changed the recommended tire pressure between MY's.)

Now if the beef is with turning a fossil fuel in to Hydrogen and the 'Well-to-Wheels' is less efficient and produces more CO² then the current fossil fuel favorite, I'm with you.
But I believe part of this research is based on storing excess Clean Electricity production in the future. (Solar/Wind-to-Wheels)
(I'm sure there were critics within toyota when some engineers started researching GM's Power Split Transmission.)

Especially in this thread which is about PHEV's that operate as EV's in limited conditions.
For example:
Press the defrost button - cold gasser lights up to make heat.
Press on the Go Pedal too much - cold gasser lights up to make more power than the limited EV power.
If you manage to keep that gasser hibernating as much as possible - you still throw perfectly fine, expensive, synthetic oil into the bin at 10k miles.
If you park outside in Tucson in the summer and charge - the pack is stinking hot.
If you park outside in St. Paul in the winter and charge - the pack is very cold.
TMS (warming AND cooling the pack, plugged in and while powered on) is a nice thing to have in a modern PHEV.

Which brings up extremes in ambient temps and Hydrogen and Fuel Cells.
Can I leave my Fuel Cell Clarity outside in -5° F winter nights unplugged? (I don't do that to my BEV...)

 

Dead weight, yes, but the BEV version also has a heat-pump versus resistance heating of the REx version. I woke up from my nap and realized I'd forgotten to mention this important omission.

In this I agree.

Part of this is choosing the right tool for the right job.

Storage is an interesting concept even though there are pretty significant conversion losses.
Robert Llewellyn's FullyCharged series details the Orkney Island hydrogen experience:

• http://www.fullychargedshow.co.uk/orkney-surfnturf/
  
• 
  
• 
  

They chose to generate and export hydrogen in a small semi-trailer. This Orkney Island experiment would be consistent with someone thinking wind-power and solar are 'free' so efficiency doesn't matter. Perhaps in Orkney but if they'd chosen battery semi-trailer or a modular Tesla battery system, their net energy would be about 2x larger. A practical example is the ferry.

A diesel electric, conversion to battery would be trivial. But even the abundance of Orkney wind and tidal power, hydrogen generation and transfer is too inefficient to support replacing the ferry diesel. So the exported hydrogen provides pier power and not a whole lot of that.

Owning a Prius Prime, I'm up to my usual tricks including finding out what happens when the battery is fully discharged and the tank runs dry. PLEASE DO NOT REPEAT! . . . LEAVE THIS TO EXPERTS (or crazy Bob Wilson.)

Temperatures like that in Huntsville, people would die. My wife would kill me.

Bob Wilson

 

That is only cost to make it at a plant.
It doesn't include transport to stations where it will need to be recompressed and chilled, the operating overhead of the station, any taxes on the hydrogen, nor a profit margin for all the parties involved.

What will the stations do if they call for a switch to the 12k psi standard that Japan is rolling out? The Mirai was already designed to use it.

The Model S is about a ton heavier than the i3, with the larger pack adding about 200 pounds. The 100D has the same drive train as the 70D. Increasing the battery capacity(why does BMW use amp-hrs? Google hits are saying 22kWh for the 2014 battery and 33kWh for the 2018) by more weight on the i3. I suspect it needs to increase the cooling system and case also, whereas the 70D Tesla could be using the 100D parts.

Either way, increasing the capacity buy 42(S) to 50(i3) percent increases weight by 200(S) to 33(i3)0 pounds or so, increases range by about 40% for each, and reducing efficiency by 5% for the I3 and 1% for the Model S. The weight increase hurts the i3 more. Which could be because it starts out so light with skinny wheels.
Compare Side-by-Side


Either way, the weight increase for longer range is not a major determent to efficiency.

My negativity is over the push for commercialization while the technology is still in a development stage. The standards for the hydrogen tanks and filling aren't completely set yet. I mentioned that Japan is already going to a higher tank pressure than the current one, and there are other potential changes there, anyone of which would require upgrading already expensive stations, and could make cars on the road obsolete.

Then the cost for distribution infrastructure would be huge. The car companies pushing hydrogen want us, the tax payer, to foot the bill for it. Tesla takes advantage of incentives and government help, but they didn't state they were car company, not a fuel one. They went ahead and made their own fast charge network, and their cars don't absolutely need it like hydrogen ones do.

Hydrogen from fossil fuels might be a carbon emission reduction. If so, it will be expensive for the decrease. It needs to be made renewably to really help, but that requires government regulations forcing the market to make it, because that costs more. If people were willing to pay, we would be making renewable diesel and gasoline now.

I said hydrogen and fuel cells could work as green power storage. In that use, the size and weight of how you store the hydrogen doesn't matter. Hydrogen tanks for cars aren't as heavy as batteries, but they are bulky. This makes packing them in a car difficult without space loss; the Clarity FCEV trunk is 3cu.ft. smaller than the PHEV model. It is easier to pack in a battery for a plug in.
2017 Honda Clarity | Features and Specs | Car and Driver

 

• Model S weight change - the incremental weight change of the longer range Tesla is closer to a rounding error. So I offered my light-weight BMW i3-REx vs BMW i3 BEV where there is a significant weight change. The range extender is an example of the weight effect on vehicle performance.
• BMW Ahr vs kWh - ordinary and 12V batteries are listed by Ahr. It is really just another battery metric and somewhat interchangeable. Typically Ahr is measured at either 1 C or 0.1 C (charge rate.)
• 22kWh (60Ah) vs 33kWh (94 Ah) - those are the rated, battery capacity, a lab measured full charge and discharge. In real life there are margins on the top and bottom that the car doesn't use. Our 2014 has an operational charge that I've measured, ~18.6-18.7 kWh at 30-31 A.

After the motor mount bolt break, the replacement parts were substantially larger and made of aluminum instead of a plastic-aluminum part. I suspect several other weak area might have been re-enforced with heavier parts. The small offset test would be another like area beefed up.

Bob Wilson

 

I googled the weights of the 60 Ahr and 94 Ahr BEV i3 and noticed that the weight increase per kWh in the i3 was quite a bit higher than the Tesla so these details you mention are no doubt part of the explanation. It also means that the decrease in fuel economy seen in the 94 Ahr i3 compared to the 60 Ahr model is a mixture of dead weight and battery weight.

One way or another, Tesla has proven that extra long range EVs can be made that are fuel efficient, in fact just as efficient as the lower range models.