Futurology

I think it is more specifically electric planes as large as commercial airline passenger planes are impossible. It has a lot to do with battery mass to energy content ratio. Kerosine is about 46.4 MJ (megajoules) per kilogram. Lithium-air batteries, for example, only have about 6.12 MJ/kg.

So, that means you need 7 times as much battery (in mass) to have the same energy content of kerosine fuel. Naively, we can maybe say that means electric planes only have 1/6 of the range of an equivalent kerosine plane.[^]

Interestingly, lithium-air batteries theoretically have the largest possible energy density for any battery at 40.1 MJ/kg.

^ The calculations are really basic and probably only slightly reflect reality (since there are many other important factors. For example, Hydrogen has a lot more energy per kilogram than kerosine, but because it is much less dense, it has much less energy per m^3 than kerosine. This has made hydrogen gas very impractical for either internal-combustion engines, or planes), but I think it gives an idea of what the problem is.

It's a problem of range. Jet planes have the advantage that they get lighter as the flight goes on, so for shorter flights, the battery issue is not as big of a problem. It's not a physical impossibility to achieve flight with lithium ion, it's a question of how far.

Assuming $8 for energy, let’s say $0.12/kWh you’re looking at 64kWH. That’s like 1kWh/mi, which is pretty fucking bad. There’s no way they’re scaling this up, because the battery has to weigh at least 1 Ton. So to double the distance you’d need to initially add double the battery, but that’s equivalent of adding 8 fat fucking Americanos to the payload, there by reducing the distance you can travel.

Meanwhile a Cessna Jet gets like 27/mi per gallon. So 2.5 gallons of fuel gets the same travel distance, and that only weighs like 20lbs.

Also, haven’t looked lately, but last I remembered, jet fuel was like $11/gal.

Does say that vertical takeoff is part of the plan. Probably worth an awkward looking plane if the goal is to eliminate the need for infrastructure like modern airports.

have you seen the state of their rail system? Americans might be dumb but they're not fucking stupid.

There's plenty of places where an electric shorter range plane makes sense. Alaska and Australia come to mind immediately.

Well it did say it was a milestone flight, as well as 68 miles not necessarily meaning on a straight road you could drive 70mph on.

There are a lot of good arguments for rail or other means of transportation, but the travel volume vs the infrastructure required are vastly different in the US than in many parts of Europe/Asia. Think 'lots of medium distance low volume routes' that aren't economically feasible since there are existing routes. If you went through the effort of building a train route, you would have to charge so much per person to make it pay for itself that no one could afford it and they would take other methods.

I'm Europe, there seem to be enough 'short, high volume routes' that are economically feasible that considering adding other legs to them make sense, or they just already work.

They envisioned travelling on the Autobahn?

Why? It's probably just an ad.

"Woke commie company out to make us all gay with electric plane!"

Better?