Comment by Lord-Jobo | Hacker News Reader

Comment by Lord-Jobo | Hacker News Reader

I think this may be wise given the rapid pace of development that batteries are still undergoing. Pretty hard to create a design around a battery when you dont even know what chemistry you are working with. And there is a bit of a revolution happening with lower carbon fuels, even though it sucks compared to pure electric, and it still has a lot of work to make sense(https://www.youtube.com/watch?v=OpEB6hCpIGM). I was under the impression though that this was a potentially good area for hydrogen fuel? can anyone confirm?

Edit: Here is the video i was looking for https://www.youtube.com/watch?v=OpEB6hCpIGM

Summary: Jet-A/A1 kerosene is the current mass fuel for passenger planes in the United States, and its dirty, but the most economical.

Simple biofuels have all sorts of chemical drawbacks that make them a nonstarter. super processed biofuels however, can match the properties of JetA/A1 very closely, but they are very recently developed. Unfortunately, right now, they cost so much energy to develop that they arent environmentally friendly at all, even disregarding the rainforest destruction it provokes (palm oils).

hydrogen may work some day but production is still too costly and it requires a complete redesign of planes and engines, unlike super processed biofuels. it also requires expensive and sensitive cryogenic storage to make energy density work.

e-fuels, or hydrogen composite fuel (liquid methanol, etc) may solve all of the above problems and grow as a more economical option rapidly, but they will still not match the cost performance of JetA/A1 which means increased costs for travel/shipping are unavoidable.

electric is an option with the most uncertainty, but there are already niche use cases that already make more sense than other options. mostly small craft and short flight distances. but that does take a decent chunk out of our current consumption. if battery chemistry keeps moving forward at a rapid pace, this could legitimately replace a lot of the air travel we do, but until those batteries are already coming out of factories, its difficult to design around.

so here we are.

Your statement sounds like a contradiction.

If the development of batteries is so rapid, Rolls Royce not investing in electric engines and doubling down on fuel-burning engines instead could open them up for a book story worthy "disruption".

By the time batteries/electric plane engines suddenly become good enough, Rolls Royce might face themselves in a "why does nobody want our fuel-burning engines anymore" situation that will require multiple years to catch up to electric engine manufacturers. Multiple years of catching up that Rolls Royce might not have at the time they find themselves in the "nobody wants our engines anymore" situation.

Rolls Royce is owned by BMW. BMW does strategic investments and R&D for them.

They just look what they need for next few models.

Different Rolls Royce: https://en.wikipedia.org/wiki/Rolls-Royce_Holdings

The Rolls Royce company of discussion is not owned by BMW. The car brand Rolls Royce is owned by BMW.

We know the laws of physics behind batteries. The theoretical best possible battery (which assumes things like spherical cows) is still very heavy compared to burning liquid fuels.

Yes battery advancement is happening rapidly, but it can only asymptotically approach the limits which are not very good for the purposes of flight.

I believe there as chemists and physicist better qualified than me to tell you what the limits are.

Moving to battery would increase demand for power, so unless we are charging all these new batteries with low or zero carbon would we not just end up with the same issue?

You're just moving the problem from the vehicles to the power generation

Last time I checked, solar and wind power were low-carbon.

> so unless we are charging all these new batteries with low or zero carbon

It's not exactly science fiction.

No, even if you're charging your batteries with carbon-emitting power plants, those plants are much more efficient than the engine in a car or plane. Internal combustion engines are very impressive technology, but they are constrained by their form factor, and can't possibly extract as much energy from fuel as a large power plant.

In reality, almost every power grid in the world is already cleaner than an internal combustion engine, and rapidly becoming cleaner as more renewable energy is deployed.

Isn't this a better outcome ? Instead of having millions of mobile sources of emissions , you will have few thousand sources of emissions which could be regulated, monitored and modernized.

I don't see the issue unless the fuel-powered cars are able to reduce carbon emissions at a faster pace than the energy grid can, which seems doubtful.

79% of new energy capacity added in 2022 was clean energy (solar, wind, storage), so yes we can expect that the increased demand for power will mostly be met with low carbon solutions.

Renewable energy is already cheaper to build than coal or gas plants in many places, and it will just continue to scale as the technology improves.

In the US on average an EV gets the equivalent of 91mpg. On the dirtiest local grid (MROE) it gets 42mpg, the cleanest (NYUP) is 247mpg. 42 isn't that great but for most driving habits it will eventually come out ahead in carbon emissions.

That's for cars, a plane's lifetime emissions are way more weighted towards fuel.

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