But planes go between very limited sets of known points, with huge amounts of infrastructure. Adding in the capability to do Al-air battery swaps / recycling would be easy, and the benefits for the use case (huge weight savings, faster turnaround times by swapping vs charging) are big.
(If you think about it, closed-loop recycling of energy storage is just another form of recharging, but with extra steps.)
The energy delivered by the battery in flight, is what you need to use to restore it back to fresh. The more energy you need the better your battery.
Why does it need to be specifically solar? Use electric from the grid, and as the entire grid changes over to other power sources so will this.
The vast majority of grid electricity is still produced from fossil fuels (at least where I live).
Additionally, a “wasteful” process, like electrolysis of water to make hydrogen, can be usefully inserted at onsite wind generation sites for when the grid isn’t requiring/buying vs sitting idle. When you see large wind turbines stopped and you know that there is a constant stream of wind at 50m above that ridge line it’s simply because the grid is not buying atm. I’m positing that aluminum air batteries are viable for aviation for the same reason.
One of the big synergies is with renewables: With the right industrial process, you can treat this smelting process as a way to dump excess energy in peak production times.
You'll have to ship the batteries somewhere they can charge/reprocess, but you also need to ship fuel, so it's a 1-to-1 tradeoff (you can ship the batteries by land).
They are swappable though: they explain that used battery packs can be replaced and that used packs can be used for a second purpose with less stringent requirements. For example, an energy storage facility at the airport.
Why not do both?
Swap one part and charge just the internal batteries. But internal batteries does not sound so clever with limited lifetime anyway.
- the power you can get from the charger to the batteries - the power the cells can accept
You can reasonably easily fix the first point with custom infrastructure, so the second point will be the limiting factor, and that one means that it always takes e.g. 20 minutes to charge your batteries, regardless how many you're charging (because with a bigger battery, you're simply charging more cells in parallel, at the same speed per cell).