Thread by @enn_nafnlaus

@nikolatrevor (1/*): Now, for the real world.

This game where we pretend that hydrogen gets super-cheap renewable power and EVs get super-expensive coal gets old. Neither gets some sort of special offer different from the other.

EV charging stations don't pay $0,26/kWh residential rates.

@nikolatrevor (2) (Ignoring that even for residential that's way over average,) just like a hydrogen production plant, chargers pay wholesale rates, which include demand charges (per kW) and per-kWh rates (far lower than residential), which may or may not vary with time or load.

@nikolatrevor (3) Depending on the pricing structure, it may be cheaper to use a battery buffer to get cheaper off-peak power. This is an expense. But the same logic applies to hydrogen: if you want cheap energy, you have to shut off your plant when it's not cheap, meaning you need more...

@nikolatrevor (4) ...capital investment per unit H2 output, which has to be amortized, just like a battery pack. And capital on hydrogen production is anything but cheap.

A BEV truck is not "300 miles". Tesla's Semi will launch in well under a year at 500 miles.

@nikolatrevor (5) Contrary to Trevor's claims, it is not "10k pounds heavier"; the tractor weight is the same as a normal diesel tractor. The reason being that you're not just subtracting the weight of a fuel tank, fuel, gearbox, driveshaft, cooling, APU, etc; the pack is also a structural...

@nikolatrevor (6) ... (stiffening) element. Also, the larger the pack, the closer the pack kg/kWh to the cell kg/kWh - which is also rising.

Trevor also glosses over what actually is involved in a fuel cell vehicle. First off, FCVs *also* have battery packs - just smaller ones, but...

@nikolatrevor (7) ...optimized for higher power (more like a hybrid vehicle's battery). Such high-power batteries are significantly less kWh, but more exxpensive per kWh, and more kg per kWh. They also have to undergo many more cycles, which involves a narrower depth of discharge - which...

@nikolatrevor (8) ... further increases the pack size. So there's still a large battery. Furthermore, fuel cell stacks are not trivial in volume or mass themselves. And the smaller you want to keep your stack, the harder you have to drive it, which decreases its already terrible efficiency.

@nikolatrevor (9) You have to deal with more waste heat, get rid of exhaust (steam) without it freezing, and in general have a more complex system.

Re, fuel cell vs. battery lifespans: you'll note that Trevor ran no numbers on fuel cell lifespans, or mention that FCV battery packs are...

@nikolatrevor 10) ... stressed *more* than BEV packs, due to having to cycle more often at higher C rates. DOE fuel cell lifespan *targets* are 5000 hours for transportation fuel cells.

Trevor wants to compare to a semi that's being driven through a full cycle twice a day.

@nikolatrevor 11) First off, let's note that you *can't* drive a Tesla Semi (500 miles range) through a full cycle twice a day with the same driver, due to legal rest requirements - and even with multiple drivers, that's a stretch. But let's go with it. 17 hours driving per day.

@nikolatrevor 12) Hey google, what's 5000 hours divided by 17 hours per day divided by 365,24 days per year?

Answer: 0,8 years. Not even a single year.

But of course, like everything, I'm sure Trevor's answer is "we'll have a magically better system that's way above the state of the art,...

@nikolatrevor 13) ... that we'll unveil at some point in the future" - said day which never actually comes. He's claimining 20k hours. But even that would only be 3,2 years - the same length of time he's damning his own (wrong) battery calculatons for!

@nikolatrevor 14) His battery prices are of course over $100 per kWh, and he doesn't bother to discuss FCV battery and fuel cell stack prices ;) This isn't even state of the art pricing today. And of course we'll ignore that you use longer cycle life products in stationary service than you...

@nikolatrevor 15) ... do in vehicles. Let's just go with Trevor's (wrong) $244k figure. For vehicles that he's wants to push the (500 mile) Semi through two daily cycles, e.g. 1000 miles per day, 365000 miles per year. A diesel semi typically average 6 miles per gallon diesel, so at...

@nikolatrevor 16) ... $2,50/gal diesel, an equivalent diesel truck would be spending $151k on diesel per year, vs. $51k in electricity, so saving $100k per year. So even in Trevor's fantasy scenario, yes, you can justify his fictional battery replacements at his fictional prices.

@nikolatrevor 17) There is no free lunch. The exact same electricity is available to hydrogen production as to EV cast chargers, under the same pricing structures - and working to optimize consumption around getting the best pricing requires additional capital investment for both.

@nikolatrevor 18) But the problem is that the hydrogen fuel cell cycle is fundamentally 2-3 times more energy consuming than the EV cycle. And if you want to be on the "2" side of that spectrum, you can't drive your fuel cells as hard, which means more of them, more mass, more expense, and...

@nikolatrevor 19) often more battery buffering. On top of all of this, hydrogen production capital costs are also significantly more expensive than EV chargers per mile of output per day.

(/end)