[lazide]

With sufficiently badly designed systems (lack of sufficient manual interlocks), it should also be possible to cause co-ordinated widespread fires and property damage or the like, with resulting loss of life.

There was a good grid generator demonstration years ago (aurora generator cyber attack), and most cheap inverters are likely even dumber than what was demonstrated there.

Likely? Probably not with current geopolitics.

Possible? Hard to say, but certainly unlikely to be completely impossible.

Security being the S in IoT and all, and most of these inverter stacks are pretty typical of IoT.