Around 3-5 years ago, Elon Musk was teasing that he thought he had a clever idea for how to make electric-powered aircraft viable/profitable with, basically, current technology ... and he was basically daring people to guess it.

Regardless of what he actually did or didn't know, it got me thinking, and I came up with an idea. I thought I'd run it past the Tildes Team, see if it passes muster.

My idea, in a nutshell, is to build airplanes with only 25%-50% of the battery capacity required for their flight (making them much lighter, with much more capacity for people/cargo) ... combined with, I'll call them Maser Cells on the undersides of the wings ... coupled with low-intensity maser beam emitters at all the major airports.

Airplanes use a ridiculous amount of energy gaining altitude. For short flights, it can be upwards of 50% of their fuel spent just getting from takeoff to cruising altitude. My basic idea is for planes to get up to cruising altitude in large circles over the airport, powered by a combination of battery power and maser energy beamed up from the airport below. Then stay in a taxi-ing circle over the airport until the batteries are fully charged, before departing. Longer flights can plan their route to include one or more detours to pass over other major airports (or other recharging hubs, like the Tesla Supercharging network, but for airplanes) to recharge the batteries along the way.

Trans-oceanic flights would be more challenging, perhaps requiring some kind of recharging hubs located midway in the oceans.

To clarify, my "Maser Cells" are similar to traditional solar-electric power cells, except they are optimized to convert either laser or maser beamed energy into electricity. These things already exist (I forget what they're called), although getting them to a high-efficiency commercial-airline level of production, that would take some effort.

There is, potentially, a lot of inefficiency in the conversion rates, from ground-generated electricity to ground-generated laser/maser, then on the plane, maser converted back to electricity into battery, then from battery into electric engines ... perhaps there are ways to reduce the amount of conversions necessary, or to increase the efficiency of the conversions. Or perhaps this is what kills the idea.

Similarly, if this were actually implemented large-scale, to largely replace fossil-fuel-driven planes, we would be talking about a LOT of electricity requirements, a lot of laser/maser emitters at every airport, and a massive redesign of flight traffic management, to allow for hundreds of planes routinely in hours-long recharging flights over every airport, all the time ... potential choke-points at various recharging hubs (again, similar to what Tesla sees at overly-popular Supercharging stations on the ground) ... and doubtless lots of other issues I'm not thinking of.

Anyway, though, that's the notion.

ETA: This idea could be extrapolated to an extreme degree, with on-board batteries almost completely eliminated.

With clearly defined flight corridors, and ground-based maser power stations located every 10-20 miles along, planes could fly their entire route on power beamed up to them, with only 20-30 minute battery capacity for emergencies.

ETA #2: A person who owned his/her own rocket company might also consider putting the maser cells on the tops of the planes, and launching a bunch of solar-power-generating satellites, with maser emitters shooting power down onto them.

I guess my main point is, if this maser-energy delivery system is even remotely feasible at a commercial level, there's a lot of potential.