Can a grid-tied solar homeowner have a backup generator installed that turns on automatically in an outage?
What happens when there is a power outage?
Is there a danger the solar continues to feed....because generator automatically supplies voltage?
Assuming that the generator output is stable enough at nominal voltage and frequency and has a low enough impedance to satisfy the anti-islanding tests to allow that GTI to run, the problem (yes, danger) will come whenever the local load is less than the power output of the panels at current light conditions. The grid interactive inverter has no provisions for throttling its output so it will attempt to backfeed current into the generator. This can cause serious problems, depending on the details of the auto-throttle and voltage regulation systems of the generator. The best outcome is that the generator frequency will go out of range and the grid interactive inverter will shut down. The worst outcome will be damage to the generator.
How is this possible with the inverter and utility isolated from the generator by a transfer switch?
He's describing what would happen if you connected the solar on the load side of the transfer switch, and then the generator came on.
Usually a load side connection is much easier than a supply side tap so one might be tempted to do it if one didn't understand how it could go wrong.
That sounds to me as if the OP is considering what would happen with a PV connection on the load side of the transfer switch. Most likely a backfed breaker in the main panel.Is there a danger the solar continues to feed....because generator automatically supplies voltage?
How is this possible with the inverter and utility isolated from the generator by a transfer switch?