Aside from it benefiting energy companies, is there any justification for such a law?

In South Africa we’ve had load shedding on and off since 2008. It’s becoming pretty standard for middle class homes to have inverters with batteries and optionally solar.

It does create an issue though that when a load shedding window ends, a whole lot of batteries start charging all at once (especially during non-daylight hours).

Also due to load shedding, I don’t get full use of my batteries. Ideally I would like my batteries to pretty much fully discharge over night with energy from my solar during the day, however, because load shedding is somewhat irregular here, I have it set to not go too low so it has enough energy to tide me over.