https://apps.apple.com/us/app/solarman-smart/id1469487897
If an attacker could control a significant portion of solar inverters in a solar dominated grid, he could cause an blackout, under right conditions.
More in presentations at CCC:
"How to cause blackout"
https://media.ccc.de/v/32c3-7323-wie_man_einen_blackout_veru...
"BlinkenCity: Radio-Controlling Street Lamps and Power Plants"
https://media.ccc.de/v/38c3-blinkencity-radio-controlling-st...
Large solar invertors at large solar plants muss be under remote controling of grid operators, to allow solar curtailment when the solar production exceeds electric demand or grid transmission could be overloaded. This is not specific to solar power plants, other kinds of power plants are also under control of grid operators.
With increased deployment of residential solar its possible that this controlling will be extented also to residential solar.