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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

#51

Post by AndriyKunitsyn »

lukev wrote: post #10
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.

Actual comprehensive high speed rail networks would reduce the overall carbon footprint of travel by a huge factor, while still permitting a high overall degree of affordable mobility.

A one-way ticket for an Amsterdam - Paris train, taken well in advance (2 months from now), costs $159.30. It's a 3.5 hours long trip.

https://eurorails.com/en/trains/amsterdam-centraal/paris?dat...

A similar one-way ticket for the same date for a flight costs $112 (with no bags), and it takes 1 hour 25 minutes.

https://www.kiwi.com/en/search/results/amsterdam-netherlands... (Yes, some people can say that Kiwi is a shady website, but it can find some good deals if used right.)

I think most of the public would choose the second option. And this is a 500km long trip. Anything longer, and planes win by even larger margin.

If you're talking about the US, there's more about its rail networks density than unwillingness of Americans to build new railroads. It's also because people... don't really like using trains for long-distance transit?

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

#52

Post by retrocryptid »

i would have given this guy credit if he compared cost of production for petro fuels when talking about energy debt.

also conflates power with energy, but fine.

if you talk about cost (dollar or kilowatt hour) per joule delivered to a vehicle and then compared the total cost of electric vs. the total cost of petro, i would listen. but he ignored the fact that petro fuels cost money, energy and water to produce.

and there some things electric motors can do that ice can't. an electric ekranoplan isn't too infeasible, but we know from soviet studies you can't keep salt water out of an aspirated motor when you're that close to the water's surface. turns out electric motors can be sealed against water.

and dissing physicists? wtf? makes me think he failed out of an engineering physics degree cause he didn't understand math. as we used to say, the limit of a bs or be as gpa approaches zero is bba.

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

#53

Post by sightbroke »

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,…

Or Nuclear Propulsion:

https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Merc...

> Nuclear ships are currently the responsibility of their own countries, but none are involved in international trade. As a result of this work in 2014 two papers on commercial nuclear marine propulsion were published by Lloyd's Register and the other members of this consortium.... > This is a small fast-neutron reactor using lead–bismuth eutectic cooling and able to operate for ten full-power years before refueling, and in service last for a 25-year operational life of the vessel. They conclude that the concept is feasible, but further maturity of nuclear technology and the development and harmonisation of the regulatory framework would be necessary before the concept would be viable.

> In December 2023, the Jiangnan Shipyard under the China State Shipbuilding Corporation officially released a design of a 24000 TEU-class container ship — known as the KUN-24AP — at Marintec China 2023, a premier maritime industry exhibition held in Shanghai. The container ship is reported to be powered by a thorium-based molten salt reactor, making it a first thorium-powered container ship and, if completed, the largest nuclear-powered container ship in the world.

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

#54

Post by philipkglass »

darth_avocado wrote: post #46
philipkglass wrote: post #33

Earlier quoted context omitted.

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…

Just build more nuclear power plants. There’s absolutely no reason why modern civilization still needs to rely so heavily on hydrocarbons. Unlimited electric energy, with a electrified rail network, public transportation and EVs for commuting, should take care of most use cases, except maybe a few where the energy density doesn’t make sense. And don’t even get me started with the “our grid cannot handle it” nonsense.…

Sure, nuclear too. I'm fine with any low-emissions energy source. Electrification can take care of most terrestrial transportation. I still think we'll eventually use synthetic hydrocarbons for long range flights and a few other niche applications like rocket launches.

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

#55

Post by pfdietz »

api wrote: post #48

I remember seeing loads and loads of analyses like this back in the 2000s on a site called The Oil Drum about why electric cars would never work at scale. (Spoiler: My family has two EVs.) They always assume that the technology will never get better, that industrial economies of scale don't exist and therefore that prices don't decrease with scale, that currently developed reserves of resources like lithium equal tot…

The Oil Drum was converted to a static archive site in 2013, in part because they were finding it hard to attract quality content.

Gee, maybe that was because it was clear Peak Oil (in the we're running out sense) wasn't happening?

This comment was made to the shuttering announcement: "8 years means The Oil Drum came online in 2005, basically matching the start the current plateau in crude oil production."

Global oil production has increased since then. The price of West Texas crude has gone from $100 (which would be $136 in today's dollars) to $64 now.

The left wing pessimism stems from a moralistic view. The underlying idea is that we deserve to suffer, so suffering is predicted.

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

#56

Post by beloch »

baq wrote: post #36

You don’t need to rant when it’s enough to show that a few dozen airliners consume a day’s worth of a nuclear reactor power production (for some size of an airplane and a nuclear reactor; we should be accurate within an order of magnitude). Imagine every single airport needing its own huge ass power plant and you get your point across in an HN comment. Not sure what’s the point in attacking physicists, either. They s…

His beef against physicists is likely rooted in confirmation bias. Musk has a BA in physics that some debate if he even completed, but one bad egg does not prove the rule. It would be just as easy to point out engineers who have gone on to lead dodgy enterprises but, again, a few bad eggs do not prove the rule.

His reason for attacking another group is likely to make his own group look superior. This works on the playground and in more professional situations than it really should. He might also just be airing his prejudices thoughtlessly.

Either way, it's probably going to limit the audience he reaches and invite some nasty responses. He'd do well to avoid spewing such nonsense in the future.

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

#57

Post by jauntywundrkind »

dragonwriter wrote: post #19
xterminator wrote: post #13

Earlier quoted context omitted.

Why can't cargo ships deploy floating solar panels to power the ship motors?

Because floating solar panels add drag proportional to their area, and it takes a lot of area of panels to power a motor that is sufficient for a cargo ship even without the added drag of the panels. Also, because oceans and the things one runs into in them aren't easy on solar panels being dragged along by cargo ships.

My understanding is that drag is more about the "front-on" view of a craft than how long the craft is.

Since solar panels are very thin and aimed up, it feels like they add minimal cross-sectional area to the craft. Your assertion seems trivially incorrect to me?

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

#58

Post by retrocryptid »

PicassoCTs wrote: post #44
dragonwriter wrote: post #19

Earlier quoted context omitted.

Because floating solar panels add drag proportional to their area, and it takes a lot of area of panels to power a motor that is sufficient for a cargo ship even without the added drag of the panels. Also, because oceans and the things one runs into in them aren't easy on solar panels being dragged along by cargo ships.

Would make more sense to produce chemical from solar energy harvested on the water fuels, collect the fuel and then use this with ships

i wish there was more talk about this. it seems i heard a lot about making hydrocarbons from co2 in the air + solar or algae a couple years ago. if your hydrocarbons are made this way it seems they would be carbon neutral.

i'm guessing there's more research to make it feasable since i haven't seen "carbon neutral gas alternative" at the local Chevron.

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

#59

Post by retrocryptid »

buckle8017 wrote: post #20
xterminator wrote: post #13

Earlier quoted context omitted.

Why can't cargo ships deploy floating solar panels to power the ship motors?

Economics. The solar panels would be more expensive than bunker fuel. Sails would be cheaper.

it might be fun to try to make a modern wooden sailing ship cargo fleet.

maybe with an emergency diesel engine in the back.

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

#60

Post by GaggiX »

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…

Considering the thermal efficiency of a modern jet engine, the usable energy compared to a lithium battery will be ~15 higher per kg, still bad, but not as bad.
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