> For example, batteries still need to be 20 times more dense before we can build a cargo/passenger aircraft with one. Significantly more than 20 times I'd bet

> For example, batteries still need to be 20 times more dense before we can build a cargo/passenger aircraft with one. Significantly more than 20 times I'd bet. The airframe will have to be significantly reinforced to support a design where the maximum takeoff weight is equal to the maximum landing weight. At that point, aerodynamics start to look a lot more like a rocket equation where you can't dump stages. I think medium to long term, nuclear or renewable powered synthetic fuel is far more likely, especially since we already have a lot of generic infrastructure applicable to fossil fuels and carbon taxes could be the thing that pushes synthetic fuel into the market.