alt Hacker NewsThis can be dangerous for utility company workers.
When a line needs to be repaired, the technician takes steps to ensure the line isn’t carrying current from known sources. A panel plugged in by a civilian via a home outlet is not known. The technician can be killed by the unexpected current.
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It can be dangerous to backfeed (which is why you're supposed to have an interlock for a generator inlet, ensuring utility power is disconnected). But:
1. These grid tie inverters are designed and tested to shut off completely if there's no grid power. (This is a big design tradeoff: it means they don't provide any power during a grid power outage, even if it's very sunny out.)
2. Even if I had a beefy generator that was unsafely backfeeding my house while the utility power was still connected, the generator would be trying to power not just my house, but all my neighbors too! And the circuit breaker and/or inverter on the generator would likely trip and shut down almost instantly.
There's still a possible risk from #2, especially if the downed wire being repaired is relatively local (i.e. your house only).
But I think #1 and #2 mitigate this risk very well.
FUD. Every inverter currently on the market immediately drops the connection if the grid isn't present, there is absolutely no way this could happen with these puny inverters.
That's exactly right, and the very reason the germans figured out a solution.
The panels are designed to not provide current if no current is detected on the mains. Otherwise you would also have a live plug at the end of the panel. Killing your own customers is typically not a good business strategy, so quite a lot of safety has been focused on ensuring this isn't a problem.