They have to. Feeding your own home needs some setup but is fine. But electricity companies require you to disconnect generating capacity from the grid when the grid is down to make it easier to effect repairs.

But that's more a policy decision than a technical restriction. We could change it so power can flow on both sides of a fault instead of only the "upstream" grid side.

With battery systems getting so cheap maybe community batteries will become a thing where a neighborhood exports it's solar too and is it's own small grid.

that would mean either:

a) government mandates that turn over existing grid infrastructure to such a project, because the existing grid infrastructure is almost all privately owned

OR

b) building new infrastructure to create an isolatable local grid

Neither of these seem particularly likely to me.

I mean it isn't though: it's defense in depth - policy is you must disconnect. Line workers will drive a ground stake in on both sides anyway, but if you don't disconnect then they'll just short your inverter to ground.

Referring more to microgrids here; think city block/neighborhood level independent grids

Ah I see. AFAIK selling electricity is highly regulated in most states so I can't imagine microgrids taking off in the US. It would be cool though

There's a program involving F150 lighting trucks out in CA that pay you to grid tie them, that way a couple of them in your neighborhood can power the neighborhood for a day or so if wildfires take out the local grid

Anything grid tied is generally required to have phenomenally reliable shutdown if the grid goes down OR proven (and very expensive) automated switching that disconnects it from the grid if the grid goes down.

This is so those F150s are not backfeeding the wires while a repair crew is trying to fix it.

Ergo, if the local grid is "taken out", those F150s cannot be "on the local grid".

I'm sure you know what you're talking about, but Duke energy is running the program, and they wouldn't be paying people to grid tie their EV for disruptions unless they could use it: https://news.duke-energy.com/releases/illuminating-possibili...

The lightning extended range has a 135 kwh battery and can backfeed 90A@240V. That's a heck of a lot of power.

Article says "customers will allow their EVs to feed energy back to the grid – helping to balance it during peak demand". It doesn't say anything about what happens when the grid goes down during disasters