The youtuber got 4-5kWh per day on his trailer. It looked like enough to supply most of his needs (all equipment is electric including a zero turn radius ride-on mower). He's only a one-man crew though. A 3-4 man crew would need a different equipment config.
Yeah - I think that is one of the critical pieces in his setup. He can have a (relatively) modest amount of batteries, and cycle through them as he's using all his tools one by one. In a big crew, where each stop every tool is being used non-stop for 30 minutes, then 10 minutes drive to the next home to repeat, batteries won't be able to charge enough. You'd probably need 3x the batteries in that case (which, per-person, is roughly the same I guess).
