

Just to play devil’s advocate. There was recently an unverified report that some inverters contained an undocumented cellular modem. If true, it could, in theory, allow for remote modification or control, even when fully “offline” as far as the client was concerned. Basically a mobile phone based back door.
The solution is better verification, rather than bans however. Grid scale devices should have the hardware randomly audited. The software should also be audited and check summed. This would be burdensome at domestic levels, but seems reasonable at grid levels.
For many places, your signal isn’t the bottleneck. It’s the back haul from the tower to the main internet. 5G won’t help if there’s a straw connected to the fire hose of 5G.