Hi everyone,
I have attached a photo of a design that I think allows me to be totally outside the scope for G99 and G100/2. I already have approval for my old 3.4kw sofar solar inverter so my new inverters will be configured as follows. Please let me know if my thinking is correct because according to G99, so long as my system remains 100% disconnected from the grid with its own earth, I’m outside th scope of G99 G100/2
Here’ the details:
This design uses one shared Pylontech battery bank to bridge two otherwise separate electrical systems: a grid-tied Sofar 3.5 kVA hybrid inverter that charges the batteries from the grid at night, and a fully off-grid Victron Quattro system that powers the house and is AC-coupled to a SolarEdge 10 kW solar inverter during the day.
The house is supplied from a dedicated off-grid consumer unit with its own earthing arrangement, while the grid-connected Sofar inverter remains isolated in a separate junction box, meaning the only connection between the two systems is the shared battery bank managed by the Cerbo GX.
In normal operation, the Sofar replenishes the batteries using cheap off-peak electricity, the SolarEdge and Victron supply the home from solar energy during the day, and anti-islanding protection in the Sofar prevents power from being exported back to the grid, keeping the grid-tied and off-grid functions electrically separated.
see attached photo for details