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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

#161

Post by class3shock »

jmward01 wrote: post #9

This appears to ignore the new technology that electric brings in: Reduced maintenance, (for aircraft) reduced weight in other parts of an aircraft, new propulsion capabilities that increase efficiency of the energy used, new performance envelopes (like flying much higher because the physics are totally different), etc etc. Sure. Take an existing vehicle optimized for burning things and just swap that small part and…

"Additionally, that 60x claim is getting old by the minute. We are getting to 300+ with advancements coming in so fast they are hard to keep track of. That 60x could drop to 10x or lower in just a few years"

What was a Tesla Model S power density 10 years ago? Today? Hardware moves slower than you think. All your points have some basis of consideration but the potential performance improvements they represent are tiny compared to the single huge downside of having to fly a giant, heavy battery everywhere and that is not going to change anytime soon.

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

#163

Post by RetroTechie »

ChuckMcM wrote: post #63
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…

Was going to post something similar. I love me a screed where the author rails against some group saying they don't know what they are talking about, and then goes on to demonstrate that they don't know what they are talking about. :-) For a long time I didn't understand what 'talking past each other' meant but this article is a good example of that. Mostly it's bad form to make sweeping generalizations. But let's be…

"Lithium propulsion for aircraft and boats is fundamentally unprofitable (..)"

It's annoying (and ignorant) author lumps aircraft & boats into 1 category.

Jumbo jets won't be electrified anytime soon. Weight (and thus, energy density/kg) is everything. But synthetic fuels, hydrogen etc might be good options.

But there's also short-haul flights. Routes with say, 15..20min between take-off & landing. For such flights, electric aircraft is entirely feasible. And being done (successfully) in some places. Not to mention eg. training aircraft.

Boats: veeerry different. Weight isn't a biggie, neither is volume. And there's short-haul ferries, long(er)-haul ferries, cruise ships, 10000+ container giants, tug boats, recreational boats that hardly ever leave lakes/canals/rivers, sailboats with engine that's mostly used while entering/leaving port but not out @ sea, etc etc.

Each of these have their own economics. Where they're used and (energy) infrastructure there, is also a factor. Container giant on Asia-Europe route? Good luck electrifying that. Small tourist boat doing 20..30km/day in a natural park? Electric is a no-brainer, today.

And there's existing vessels vs. newly built ones. Most boats get old (like aircraft), more so than cars. Retrofits can be difficult/expensive. But for yet-to-build boats, different story.

Lumping that all in 1 aircraft/boat category, and claiming "uneconomical!" is just dumb.

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

#164

Post by hedora »

zik wrote: post #91

His estimate the LCoE of an electric vehicle with lithium batteries is off by a factor of ten. My back-of-the-napkin calculations make it to be $0.22–0.25 per kWh. Let's compare two vehicles - an EV car vs an ICE car - in terms of their energy costs per mile, including energy storage. Using the above numbers the EV comes out to around $0.07 per mile including the lifetime costs of the battery, and the ICE comes out t…

Another way (from first principles): Assume you buy two cars per driver. The driver parks one car at their solar panels at a time, so one is available for use 100% of the time, and at least one can charge off the panels 100% of the time.

Assume a 10kw solar system with no batteries, but with a level 2 charger. That costs $28K this year. Assume $50K per car. The system cost is $128K.

Assume the climate is such that you can charge the cars at 6kw (max output of the charger) for an average of 8 hours a day (pessimistic in summer, optimistic in winter).

This setup should last about 10 years. (Or sell the cars after 5 and get money back for new cars.)

That’s 365 * 10 * 8h * 6kw usable for the cars, or 175.2MWh, giving us $0.73 per kWh. Clearly the sky is falling. I’m going to get a steam engine for my buggy!

I forgot to figure the depreciation of the cars. We wasted one because this scheme is dumb, so the depreciation for an equivalent ICE car would be zero. For the other car, I think it’s reasonable to assume 90% depreciation. Say the ICE car depreciates $40K. We can sell the two EVs for a total of $10K. Now the total cost (sans car) for the system is $78K, or $0.445 per kwh — cheaper than California’s grid.

I forgot to figure interest on the $78K of capital. At 8% average return, that’s a bit over 2x, getting it closer to a dollar per kwh.

For a 4 mile/kwh car, that’s $0.25/mile. Of course, if you assume the existence of civilization, then the price drops a lot. For instance you could only buy one car, and you could size the solar smaller, or also plug the house into it.

Anyway, in my hypothetical mad maxian hellscape that’s experiencing healthy, steady economic growth and has access to cheap refined gasoline, he’s still off by a factor of 2.5x.

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

#165

Post by Animats »

londons_explore wrote: post #156
Animats wrote: post #123

Earlier quoted context omitted.

Probably not. Hydrofoil boats work OK, but few applications need the speed. The US Navy went through a period of hydrofoil enthusiasm, and built some.[1] Boeing built a hydrofoil ferry, and some are still in service. The Navy version used 10x as much fuel per hour in hydrofoil mode, running off a gas turbine. Of course, it was going fast in that mode. [1] https://www.youtube.com/watch?v=zQ2sSRBMPqs

> few applications need the speed. Speed is key to profitability for most usecases. If you are transporting people from A to B, and you can do it in half the time, then you can make twice as many trips per day, doubling revenue (or, if there isn't enough demand, you can buy a smaller boat and reduce your capital costs whilst maintaining the same revenue). And thats before you consider that by going faster you might w…

Not in shipping. See "Slow Steaming".[1] Most container ships could go much faster than they normally do.

Sadly, the S.S. United States, the fastest transatlantic liner ever, is about to be disposed of by sinking.[2] 35 knot top speed. Southampton to New York in 3.5 days. No market for that once air travel crossed the Atlantic.

[1] https://en.wikipedia.org/wiki/Slow_steaming

[2] https://6abc.com/post/what-are-doing-ss-united-states-histor...

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

#166

Post by hedora »

class3shock wrote: post #161
jmward01 wrote: post #9

This appears to ignore the new technology that electric brings in: Reduced maintenance, (for aircraft) reduced weight in other parts of an aircraft, new propulsion capabilities that increase efficiency of the energy used, new performance envelopes (like flying much higher because the physics are totally different), etc etc. Sure. Take an existing vehicle optimized for burning things and just swap that small part and…

"Additionally, that 60x claim is getting old by the minute. We are getting to 300+ with advancements coming in so fast they are hard to keep track of. That 60x could drop to 10x or lower in just a few years" What was a Tesla Model S power density 10 years ago? Today? Hardware moves slower than you think. All your points have some basis of consideration but the potential performance improvements they represent are tin…

Battery density doubled in the last ten years:

https://www.westchestercleanenergy.com/post/lithium-battery-...

Density is going up exponentially in the graph because it has been improving 18% for every doubling of the number shipped. Global EV market share is projected to cross 25% this year, so we should expect two more 18% improvements as it approaches 100%. That should improve density 39%. Then (ignoring batteries sold so far, and assuming there are no new markets for lithium batteries), we’ll see another 18% in 2 years (164% of current density), 4 (193%) 8 (228%), and so on until some theoretical limit is hit.

In all likelihood, some other technology will replace lithium batteries at some point. That further improves the density numbers.

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

#167

Post by hedora »

dmoy wrote: post #70
seb1204 wrote: post #68

Earlier quoted context omitted.

This is not correct for electric trucks. Replacing diesel motor and gearbox with battery pack and electric drive train is close to a zero sum game according to https://youtube.com/@electrictrucker?si=RjdWBQQXansebUyJ Definitely not a huge penalty.

Fair, but the context here is planes (and boats I guess though that seems less difficult than planes)

Container boats are ridiculously carbon efficient because they move unimaginable amounts of weight (amortizing any fixed costs like keeping the engine running) slowly (low drag) over a perfectly level surface (no loss from going up hill).

Almost any carbon reduction scheme that involves doing anything other than using them doesn’t work.

For instance, the embodied carbon of an apple that goes from China to the US, then is driven to a Walmart in a diesel train / semi is probably lower than the carbon footprint of one from the local farmers market (unless the farmer drives the apples to market in an EV and the local power grid is low carbon).

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

#168

Post by hedora »

dontlikeyoueith wrote: post #140
sitharus wrote: post #89

Earlier quoted context omitted.

Where I live companies are moving to electric ferries because they’re cheaper to operate, require less maintenance, and are much quieter for the passengers. Plus they don’t emit any exhaust fumes while idling at the dock. The port also has an electric tug boat, which their reports say is very handy because it changes power output much faster than diesel tugs. Charging times are not a factor according to their reports…

> the minerals in batteries don’t disappear after use. For all practical purposes they might, depending on how the batteries are disposed of.

It seems unlikely that the disposal will leave the lithium in a state that’s harder to refine than natural deposits (which are extremely dilute).

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

#169

Post by hedora »

chris12321 wrote: post #7

I recently read The Ministry for the Future by Kim Stanley Robinson, and one of the ideas in it that I thought was very good was replacing our cargo ships with wind-powered ships, basically giant sailing ships. In the book, they were incredibly slow, with shipments taking months to complete, but if supply lines were set up correctly, that wouldn't matter for a lot of cargo. Cargo ships are a massive CO2 contributor,…

> Cargo ships are a massive CO2 contributor

Not really. They’re 1.6% of global emissions if I multiplied the numbers on this page out right. The table says they’re 20% of shipping emissions, and the intro says shipping is 8% of global emissions (excluding ports and warehouses).

This result seems surprising until you realize that semi trucks produce 100x more CO2 per kg-mile of cargo.

https://climate.mit.edu/explainers/freight-transportation

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

#170

Post by jmward01 »

MegaButts wrote: post #50
jmward01 wrote: post #9

This appears to ignore the new technology that electric brings in: Reduced maintenance, (for aircraft) reduced weight in other parts of an aircraft, new propulsion capabilities that increase efficiency of the energy used, new performance envelopes (like flying much higher because the physics are totally different), etc etc. Sure. Take an existing vehicle optimized for burning things and just swap that small part and…

> reduced weight in other parts of an aircraft The bigger problem is that the overall weight increases. Rearranging the COG doesn't really matter when most of your energy is spent literally fighting gravity. This is the first thing that popped up in google when I wanted to compare gravimetric density between gasoline and lithium ion batteries. Gasoline is still approximately 30x denser. That is at least one revolutio…

The point was the other parts of the plane. No lines moving all that gas around and the pumps and the plumbing in and around the engine and the bleed air piping and the and the and the.... There are a lot of potential places to shave weight when you go electric. An aircraft optimized for electric will be massively different if done right.
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