I think you will find that when one is generating power the power not used in the house is going into the grid but the meter is in effect running backwards so you do really get full saving benefit from it, just no cash.
No, I am afraid that is not true, wish it was. If there is no buyback rate then there is no saving or money being made from the power you are generating that you don't use. Of course, the power you do use during the day (and you are always using some for things like fridge even if you are not there) is free, which means you save 32c per kwh, which is the standard NSW charge.
Gerty, in NSW AGL is offering 9c per kwh and Essential Energy 8c, (at least they are in Coffs Harbour where we are building our house) although not on all plans. Give them both a call and ask them what they will offer you, you will probably find you can get a better deal over the phone than appears in their brochures.