Solar power Anti Islanding The cost ??

Hello all   G99  etc consumer advice  What are the standby running costs to monitor grid fail and and eventual inverter physical separation ?  Anyone know ? 

Q: How is physical separation achieved for islanding protection when grid is detected as down ?  There is much tech mumbo jumbo " phase detection " zero crossover " but no genuine answer as to what the standby costs of running all this this actually is 

Appears ( however fail is detected ) final physical separation is achieved by a plain old electro mechanical contactor ?  It is simply de-energised  Contacts separate and we are done ? 

Could it be that these power  devices are maintained energised all year 24/7 consuming power until here is an issue ? 

If so can the solar grid tie industry tell us what power is consumed in this effort and where does it come from ? 

ciao Ms Otis