The sine wave syncing is probably the only real issue.
There have existed automated transfer switches for years and years. My FIL, when he lost power, would very loudly start a countdown from 60 to 0, where his system would kick over to natural gas via the detection of a power-loss event, via an automated transfer switch.
There have existed automated transfer switches for years and years. My FIL, when he lost power, would very loudly start a countdown from 60 to 0, where his system would kick over to natural gas via the detection of a power-loss event, via an automated transfer switch.