I think synchronized operations could really disrupt the grid — think thousands of inverters switching backfeeding to the grid on/off, causing waves and disruption. Or thousands of inverters having their grid sync disabled, simultaneously operating to shift the frequency of the grid (very bad).

I'd be worried about the inverters in large commercial solar plants. On a sunny day you could easily cause a blackout by turning enough solar capacity off at once. Maybe shut down the entire grid when the sudden power imbalances trip the self- protection in half the grid. That's a pain to recover from. Spain went through that not too long ago

But maybe rapidly switching residential solar on and off in a coordinated way can also do funny things to grid equipment

If you had enough systems under control in an area, you could probably create a brown out or some other type of scenario by turning off 1000 houses on the right day.

Any idea what happens to the grid when a significant chunk of solar power suddenly disconnects?

nah, the ones connected to the grid... you turn them all off during peak sun hours at the exact same time

same issue with large loads like boilers, this stuff should never be connected to the internet, but it is

if you can control enough load on the grid you can do real damage

DDoS, anonymizer proxy, and turn off power in large commercial installations. They kinda deserve it for investing in solar. US holds all the power in social media, can't blame China if they want to utilize their lead in solar for something too.

Hopefully mutually assured annoyance keeps everyone at bay.

To set roofs on fire?

In the end it's all about trust. Right now I don't see why China would like to burn down their market.

Some of those are networked I think?

To piss away decades of hard-earned trust in its products for some short-term one-time political 'pwn' of the enemy.

If that goal sounds stupid to you, that's because it is. I would expect some countries that are not China to act with such a capricious lack of foresight.

Track usage patterns to know when people are at home and then rob them.

The HN version of "I have nothing to hide."