For a small tank of 125litre it will by default be at peak setting. You can have it on off-peak but you would probably run out off hot a lot water (dependent on your schedules).
If you call Origin and if your street has gas mains you might be best off asking them to install it. They kept extending their free offer of gas installation so it still might be valid. AGL charge 600 buckeroos.
Otherwise going to solar has a huge rebate.
Xav

