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Factor in complete system requirements—cooling, casings, and safety systems—that 270 Wh/kg battery delivers only 170-180 Wh/kg of usable energy.

Jet fuel still maintains an 18-19× energy density advantage (3.2 kWh/kg vs. 0.17 kWh/kg) at the system level, which explains the fundamental range limitations we're seeing in electric aircraft development.

For VTOL applications specifically, it demands 2.5-3× more energy per mile than conventional flight, electric air taxi prototypes remain limited to 60-80 mile ranges—impressive engineering, but not yet practical for replacing most aviation applications.


I'm sorry, what? That is an absurd assertion. Batteries are incredibly efficient, like 95-99% discharge efficiency for capacity. They're already bad for this use case, exaggerating it just makes you look bad.


former engineer, but w/e.


I found it funny that you felt a need to comment on the “finance bro”-label while simultaneously labeling HN-users as “programmers”:

> I'm getting roasted by programmers, I'll survive.

… often chosen as a sufficiently insulting label to dismiss software engineers.

I may be interpreting your choice of words beyond what is reasonable - as you said: you’ll survive ;)


HSR infrastructure costs $50-80 million per kilometer in developed countries.

:(


At 10-15% conversion efficiency, you're burning 85-90% of your energy just making the damn fuel, requiring 6-7× more renewable infrastructure than direct electrification. Current production costs are $15-25/gallon (not the fairy tale $2-3/gallon of jet fuel), and the physics won't magically improve to hit their "3× oil prices by 2050" fantasy. To replace global aviation fuel would demand a staggering 32,000 TWh of new clean energy generation – that's roughly equivalent to building 900 nuclear plants just to make luxury jet fuel while the rest of the grid still burns coal.


You've not actually addressed the cost points he makes. You seem to bediscounting the sheer cost effectiveness of renewable power because if an ideological opposition to it.

The wonderful thing about looking at how much something actually costs is you don't need to do all the work yourself - just look at the expense of the inputs and calculate your output. Solar panel electricity is absurdly cheap.

In any case it's obvious that current direct electrification is not feasible using current battery tech, so alternatives need to be explored. Unless we find a battery tech with 10x energy density batteries aren't likely to be viable in the air.


Density is a must have in our civilizations....


fair point, but most people don't open up chemistry books.


impractical, the number of ships to install these things is already constrained, not to mention the dispatch, repair, and transmission costs.


The energy required to extract, process and manufacture lithium batteries (70% of total lifecycle energy occurs before the vehicle moves) Grid transmission losses (5-8% average, up to 15% in extreme conditions) Battery charging/discharging efficiency losses The dramatic efficiency reductions in adverse conditions (33% range loss in cold weather)

For aircraft and marine applications specifically (which was my focus), the energy density problem (60x worse than jet fuel) creates cascading inefficiencies as you need more battery weight, which requires more energy to move, which requires more batteries, and so on.

Electric cars have different economics than aircraft/boats and can make more sense in certain contexts. But my analysis was specifically about why lithium propulsion for aircraft and marine vessels faces fundamental economic and physics challenges that can't be solved with current technology.

The tires on an electric vehicle wear down about 20% faster because of the load bearing of the battery weight.


70% of total lifecycle energy occurs before the vehicle moves

that's partially because the operating costs are very low, which is a good thing.

Grid transmission losses

what about the cost of shipping gasoline?

The tires on an electric vehicle[...]

this is part of what leads me to think your entire article is just anti-EV sentiment wrapped in a facade of being about planes, so you can point to the planes when people criticize it. most people here are not arguing that it makes sense to put batteries in planes, they're pointing out the very obvious inaccuracies in basic calculations like the $5/KWh the article leads with. and I also take issue with the un-cited sources (a link to a home page is not a cited source).


I agree that planes are not likely to be electrified in the near future with current tech. Not sure about marine though.

Ships benefit from the square/cube law: square the hull area -> the volume is cubed.

E.g. if you double the size of a ship, the drag increases 4x but it can carry 8x the weight.

So larger ships are more efficient than smaller ones (at carrying containers/bulk/etc at scale).

Here in northern Europe, we already have electrified car carrying ferries etc.

Ocean going vessels will take longer though.


Sulfur Hexafluoride and Nitrogen Trifluoride proliferate under a CO2 minimization regime. Nobody is arguing with Arrhenius proofs.

Nitrogen trifluoride (NF3) is a potent greenhouse gas with a global warming potential (GWP) of 17,200 over a 100-year period, meaning it's 17,200 times more effective than carbon dioxide (CO2) in trapping heat in the atmosphere. This GWP value is used to calculate the CO2 equivalent of NF3 emissions.


Who said CO2?

Who came up with the idea that someones arguing with Arrhenius proofs?

What does our proof showing the existence of other greenhouse gases help us with?

Does any of this shed any light on whether it will be politically palatable to be doing fossil fuels i 20 years?


Yes.


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