Comment by leonidasrup

https://www.reuters.com/sustainability/climate-energy/ghost-...

"However, rogue communication devices not listed in product documents have been found in some Chinese solar power inverters by U.S experts who strip down equipment hooked up to grids to check for security issues, the two people said. Over the past nine months, undocumented communication devices, including cellular radios, have also been found in some batteries from multiple Chinese suppliers, one of them said."

It would not suprise me if not only Chinese manufacurers did this. Cellular modems are cheap and and the capability to cause blackout is very usefull.