If you watch Elon's interview on the Joe Rogan podcast, he actually discusses VTOL electric aircraft using regenerative descent braking. essentially the only ad

If you watch Elon's interview on the Joe Rogan podcast, he actually discusses VTOL electric aircraft using regenerative descent braking. essentially the only added energy is air resistance plus charging inefficiency, his back-of-the-envelope math was somewhere in the 92% end-to-end range.