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Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

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Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#101

Post by kumarski »

decimalenough wrote: post #11

I can buy these arguments for airplanes. I'm more intrigued by the throwaway tweet claiming "electric scooter companies can never be profitable", because I don't see why this should be the case, unless "scooter" here is referring specifically to Ola style light motorcycles that compete directly with ICE equivalents, and not Lime style electric kick scooters that don't?

Fair point, check the post again, I've posted on twitter about the benchmark for productively profitable venture and PE dollars.

It's our taxpayer dollars at work.

As a public market pegged to the same grid constraints, I prefer $POWL over most of the private lithium companies being pitched.

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#102

Post by kumarski »

MiguelHudnandez wrote: post #22

I appreciate by default any attempt to make a full accounting of the costs involved in energy transmission and storage. Many of these grid & battery costs are abstracted away from consumers and great effort must be made to understand them fully. That said, have you done a similar analysis involving the costs of removing finite organics from the ground, burning those, and releasing the byproducts into the atmosphere?…

Yes.

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#103

Post by kumarski »

refulgentis wrote: post #80

This is a really nice article, in that its long and provides a good example of knowing everything yet nothing. Setting aside individual problems with it, this is because it suffers from a broad and blindingly obvious problem: investment is occurring in this area b/c it will be absolutely politically unpalatable in 20 years to still be emitting CO2. A long analysis showing lithium is more expensive than just using gas…

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.

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#104

Post by asn007 »

wkat4242 wrote: post #90
retrocryptid wrote: post #64

Earlier quoted context omitted.

but the metric the OP was using was power density. nuke fuels are MUCH more energy dense than hydrocarbon fuels. but putting a reactor on each plane would probably have negative externalities. but mixing your comment with a few others, maybe a nuke plant on the ground that cracks the co2 in the atmosphere to make carbon neutral hydrocarbon fuel.

> but putting a reactor on each plane would probably have negative externalities. Probably? It would be a disaster every time one crashes, would carry a huge proliferation and terrorism risk. Oof. In the 50's some countries were that crazy and they even put reactors in space. Two of which crashed and one contaminated a huge area in Canada. Luckily common sense prevailed and these things don't happen anymore. Though n…

Correct me if I'm wrong, but I thought we still use RTGs in space on some satellites? Not counting extraterrestrial research, since those are definitely still powered by RTGs

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#105

Post by kumarski »

Workaccount2 wrote: post #73

Your being a bit disingenuous by not comparing the relative efficiencies of electric vs gas propulsion. Electric motors are ~3x as efficient. They also can recharge by capturing energy during use. In a car for example, you need about 9 gallons of gas in a 33mpg car to get 300 miles. This is equivalent to a 75kWh EV. On paper though, with the conveniently leaving out details math this guy is using (or maybe it's too p…

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.

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#106

Post by svnt »

MostlyStable wrote: post #25

Just going off the tweet about electric scooters being a scam: Nothing in that tweet is convincing. Let's just take at face value the assertion that a KWh of energy in an electric scooter costs $5 (as an EV owner: I'm skeptical). I'm going to use Lime (an SF based scooter rental company, chosen at random) as an example. I tried finding exact battery specs, and couldn't, but based on the range and some general scooter…

He is for some reason comparing the levelized cost of energy. This is a metric used to analyze energy generating devices, not energy consuming devices.

His tweet says that if you wanted to buy electricity from an electric scooter and use it to run your house, it would cost the utility providing it $2 to $5/kWh, assuming that the sole function of the scooter is to provide its electricity to consumers directly.

LCOE goes up the further you get from the source, but his analysis is also based on outdated numbers and largely wrong.

That said, he isn’t totally wrong. Electric marine has a tough road ahead of itself due to the inefficiency of boats relative to cars. Boats can be calculated roughly as a car that is always going somewhat uphill.

Electric planes are a niche use case for the foreseeable future.

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#107

Post by kumarski »

AndrewDucker wrote: post #35

If you used floating wind/solar farms as recharging points across the ocean, how much space would they take up?

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

Re: Electric Propulsion's Dirty Secret: Why Lithium Can't Fly (Or Float) Profitably

#110

Post by kumarski »

philipkglass wrote: post #33
lucidguppy wrote: post #2

Flight is a luxury of the current times that will likely not last another 100 years except for the very rich.

I believe that by 2050 synthetic hydrocarbons made from carbon dioxide and clean electricity will be deliverable at a real (inflation adjusted) cost less than than 3x current oil prices, on an equivalent-energy-content basis. That could more than double the costs of a transatlantic flight, but still wouldn't price it out of reach of the upper middle class. Synthetic methanol made with renewable energy has already bee…

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.
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