When home renewable reaches a level of penetration where simultaneous loss would be in excess of spinning reserve any further embedded generation will be regulated in such a way as to not contribute to the problem. For instance by prohibiting exporting energy back to the system, and separating your house from the system if the frequency is falling quickly and your embedded generation is going to trip,in order to avoid the simultaneous load step due to the loss of all the embedded generation they could just disconnect it all. And in that case the embedded generation can continue to feed your house if it can operate an isolated network.
Isn't that the problem, that every home device will disconnect at roughly the same time? Leaving the atrophied generators to take up far too much slack.
Embedded generation will firstly displace local load before exporting any power back to the system. If the generation disconnects all you are left with is the load. If the frequency is falling and the ROCOF protection is going to cause the generation to trip, better to trip the load too otherwise the system just gets an increase in load.
