That's only like 300 * $100 for the panels if you buy them used. That's less than a Model 3. Installation usually costs far far more than the panels. If you have plenty of room and you can install them on the ground, and you are remote enough you can do it without permits or permits are easy to deal with (so really this means not California or New York) and wind isn't a huge concern (so not the Atlantic or Gulf coast) and your neighbors aren't constantly in your business (so not Texas) then this is easily done by someone who has a strong interest, a moderate income, and is a little handy. It is especially easy if you live somewhere so dry that wildfire is not a huge concern, and of course you need enough sunny days for it to be economical somewhat (although with this many panels you could live off this setup even in an Alaskan winter). My guess is they live in New Mexico or Nevada.

> That's only like 300 * $100 for the panels if you buy them used. That's less than a Model 3. Installation usually costs far far more than the panels.

I brought it up more for the space requirements. That’s a physically huge system. Panels are only a fraction of the overall cost. Unless you have a massive commercial building somewhere, 300 panels are going to take up a huge amount of ground-mount space. You also need a lot of inverters, wiring, etc.

Sure, somebody could do this with enough money and motivation, but the second question becomes: Why? That’s an order of magnitude more power than you’d need to cover a typical house’s energy use and top up those batteries.

I don't think it's very hard to EMP harden anything that has a physical size less than a few hundred meters. The power grid is in danger because there is a huge potential created over very long distances. I think to be protected from EMP just requires isolation from large DC voltages, which can be done with an isolating transformer and some varistors? But something which is not miles long and isn't connected to the grid won't really be touched by an EMP anyway.

A couple hundred panels is less than half an acre or so.

Which, yeah, completely un-doable in manhattan (they already rules out NY anyways), but 10 acre lots are a thing in plenty of places.