Hey Dallas
Randwick did something small scale a good few years ago however not directly tied to individual property rates. The link to rating was an Environmental Program (of spending) entirely funded via an Environmental special rate. Part of that program of spend provided some monetary benefit/incentive to dwellings taking up solar (I’m sketchy on details). The Revenue Team looked after the special rate – not the program of spend tied to that special rate (and there were many elements of environmental spending).
Like other councils, Randwick looked at the mechanism of Environmental Upgrade Agreements at that time and chose not to go down that path.
If you wanted to talk to them, I’d chase up the Environmental Team at Randwick. They ran the incentive/program. I seem to recall that it was small scale (tokenistic even).