silentbutdeadly
has some good things to say
We don't have off peak. Single rate only. So our solar covers it nicely...Not sure what solar setup you have but off peak tariffs are metered separately and not linked to a PV feed in, at least not here in QLD.
Also you get STC credits for a heat pumps of around $900 depending on which zone you live in.
Tip: claim them yourself not through a retailer that sells you the product as they generally give you less.
We didn't claim anything in terms of rebates because our electrician never sent us a bill for the installation...