[Reason077]

That’s true today. But in the coming years and decades, ground transport will be largely electrified and it’s per-mile emissions greatly reduced.

Hopefully, aviation can be electrified too one day (or it’s emissions reduced with hybrid technology), but unlike ground transport, the technology is not quite here yet.

[smolder]

Hybrid tech doesn't help at all with with planes. There is no braking energy to be regained and batteries are too heavy. It has no place there until battery energy density approaches that of fuel, which would require a huuge breakthrough of some kind.

[Reason077]

The idea behind a hybrid aircraft is that eFans (electric fans) are more energy efficient than a turbofan, so you can burn less fuel for a given journey.

Companies including Airbus, Siemens, and Rolls Royce are actively working on this technology with a view to have working prototypes in the early 2020s.

Besides that, there is some "braking" energy to be recaptured during descent or when slowing the aircraft. This technology already exists today: The Pipistrel Electro can regen it's battery during descent. This is similar in principle to the ram air turbine (RAT) in conventional aircraft.

[smolder]

Well thanks for the pertinent info. I was pretty sure of myself that the cost benefit ratio wasn't there but if there are engineering efforts towards it there's at least potentially some merit.

I wonder, does the efficiency gain from efans and a generator apply to a single engine setup as well as it does to multi engine setups?

[mehrdadn]

With battery capacities being what they are you'll also have to hang tight for the moment when they stretch long enough to allow you to even have the choice of driving to the same place you can fly. (Or swap batteries on the way somehow... not sure how well that would work.)

[Reason077]

This is already solved in technology terms. Battery capacities and charging speeds are already good enough for almost all long-distance travel scenarios.

It’s now just a case of getting costs down and infrastructure built out. But that’s the easy part.

[mehrdadn]

> his is already solved in technology terms. Battery capacities and charging speeds are already good enough for almost all long-distance travel scenarios.

Really? It seems to me that decent EV ranges are around 150mi right now, with the best ones going to 300mi... meaning they generally might get you halfway from (say) SF to LA, and you can bet that none of them will get you all the way. And that's not even that long of a distance, depending on what your standards are. Now charging times run into multiple hours, right? How is that even remotely close to gasoline?

[Reason077]

Charging times are around 45 minutes today for 250-300 miles of travel. Most people want to take a break after 4-5 hours of driving anyway, so it’s just a case of having chargers in the right locations.

The new generation of 350kW / 800V chargers will bring that down into the 15-20 minute range.

[mmt]

> Most people want to take a break after 4-5 hours of driving anyway

I realize I'm not most people (I love to drive), but this seems like it's bordering on extraordinary-claim territory. I don't actually expect evidence, since this would be the kind that's particularly difficult to gather (you could ask people, but what people say doesn't necessarily translate to what they do).

Regardless, it seems unlikely to me that anyone would want to be forced to take a break at the 4 hour mark rather than waiting for their destination at the 5 hours mark (e.g. SJ-LA).

I realize, of course, that it's just a matter of (not that great a) degree between 20 minutes every 300 miles for charging versus 10 minutes every 400 miles for fueling. However, because we're not even there yet for a comparably-priced/affordable electric car, it may be premature to think that way.

[mehrdadn]

I agree it was a little harder to swallow but it wasn't really "extraordinary". It's pretty normal to take breaks to stretch, eat, use the restroom, etc. during a 5+-hour ride. On top of that, given how doctors say you should get up and walk around in an airplane every few hours at least, I imagine it's not healthy to drive 5+ hours nonstop on the road either, in which case you arguably should be taking a break if you're one of those who doesn't.

[Reason077]

"it seems unlikely to me that anyone would want to be forced to take a break at the 4 hour mark rather than waiting for their destination at the 5 hours mark (e.g. SJ-LA)."

If your destination is only 1 hour further away, then you're only going to need about a 10 minute charge, not the full 45 minutes. And you can stop pretty much anywhere en route where there are chargers available, it doesn't have to be at the 4 hour mark. Plenty of flexibility there.

"we're not even there yet for a comparably-priced/affordable electric car"

I agree, but they're getting close already when you consider lifetime costs including fuel and maintenance. And the more driving you do, the more financial sense an EV makes. That's why we're seeing taxi operators embracing EVs enthusiastically.

[mehrdadn]

Interesting, I didn't realize that, thanks. But these must be the best cars, right? Not typical?

[Reason077]

Right. But where Tesla is today, the rest of the industry is heading. That sort of range and charge speed should be typical for mid-range electrics by the early 2020s or so.