While doing research for a friend who was trying to minimise her power bill and had a grid connect PV system installed. I found that there is in NSW at least a wiring anomaly that has you receiving $0.08 per Kwh for your excess PV power and at the same time you are buying your own excess electricity back again at $0.18 per Kwh. The circumstances are, and this only applies to those with Off Peak rate 2 ( 10 am to 5 pm) water heating for small capacity hot water systems
(1) You have a grid connect PV system with a FIT of $0.08 per Kwh going through a Bi directional PV power meter to the grid.
(2) You have an small electric hot water system connected to off-peak rate 2 ($0.18 per Kwh) that is separately metered.
(3) You use hot water during daylight hours while the PV system is busily collecting power for you.
The electricity you generate goes out through the Bi Directional meter to the grid and you receive ($0.08 for it, and at the same time your hot water system is heating up using your own solar power via its own meter and you are being charged for that power at $0.18 per Kwh giving the energy retailer an instant profit of $0.10 per Kwh
Putting it simply your solar power goes out through your PV meter and back in again into your hot water heater via the separate Off peak meter.
I asked numerous solar installers about and they deneighed that it could happen until I found one who would listen and really understood how the system is connected and he agreed that it can happen and he had never realised it until I brought it to his attention.
Moral of the story " Go solar hot water before going solar power"