Should be made clear, however, that ACCORDING TO PRACTICALLY EVERY POSEK, electricity in EY is NOT produced b’Issur and is halachically permitted.
This is because the electric company supplies the entire grid and at any given time there are certainly people who need electricity in their homes as a matter of pikuach nefesh.
And within each neighborhood or street, they need to supply the entire grid.
Those who use neighborhood generators on Shabbos generally do so as a matter of chumra, not min ha Din.
This is why they might use the Shabbos generator for their lights, but use regular electricity for air conditioning, especially in shuls — and most everyone outside of Bnei Brak (yes, I’m sure someone could cite exceptions) does daven in shuls with AC powered from the regular grid.