Sounds like it's sorted itself out a little.
Yes, you have to watch plan type and rates when you update to solar, and perhaps just when someone gets a new digital meter.
I found the with old analogue meter we were of course on singe tariff, with off peak for HW, when we had solar put on we were moved to a TOU (time of use) plan, where the whole structure of the plan could mean greatly increased cost overall for many, with evening peak rates being very high (and in SA very long time periods).
As we are in a partly work from home / semi retired situation, that was ok, we could juggle and adapt to change.
Later, we found out you can have a choice to stay on single rate, or move to TOU, but no one, not the solar sales people, nor AGL advised or mentioned this part of the change at all.
The worst part was our provider set up the board like for like, so they put in the CL (controlled load) meter for the HWS, and that is it's own circuit, not affected by the solar production.
Again, solar sales didn't talk about this, neither AGL or our DNSP mentioned it, it was just done.
That was costing us $1.40 a day or so, eventually I had my sparky put this on the regular circuit, with a Hager timer breaker, set to EV times 0000-0600 (also on the EV night saver plan), now power for the HW costs at most 40c a day.
Note, THIS could be your issue if you have an electric HWS on CL, not sure how you are getting the EV usage costs, but if you are reading an overview total cost divided by usage kwh and not allowing for any potential CL HWS usage, this could be the issue.
Also note, to get the EV night saver rate, you must be on TOU, no option to stay on single rate (if your DNSP or AGL has the option).
It's a minefield now Andrew, sounds like your setup might see you neutral at least (you must have a battery too ?), perhaps with some spare battery to take advantage of some good evening FIT rates (usually for 3 or 4 hours) if you can spare some.
AGL has the battery rewards (4hrs evening peak 5-9 = 26c / kwh FIT), note that I personally am not keen on the VPP concept (where control over your battery is handed over to the retailer 24/365), but if you can get 26c (I think) for that 4 hours dropping some to the evening grid, it can get you some possible daily supply charge reduction or elimination.
How much you can drop depends on your export limit set by the DNSP, your inverter size, but most good systems now with battery would have 10kw inverter, so with 5kwh export you could send up to 20kwh to the grid in 4 hours evening peak ($5.20), if flexible exports in SA and some other states now / soon you could send 40kwh, and that's per phase, so if you have a massive battery size, and you have 3 phase, you can triple that.
Batteries open up a whole new world of options for various retailers, plans, benefits.
