@Julian34 . . . like the 2 previous posters from last year, you have to really be on the ball with solar cos, and somehow try and work out if the install and connections were all ok.
You shouldn't HAVE to, but it seems you must to be sure you are getting what you should from solar, or solar with battery . . . they are 2 different elements, with 2 vastly different outcomes / effects on power bills.
I have had multiple issues with my solar only, and have posted about some of these on another thread.
Through our first winter, I put down a VERY low production to both winter sun angle, and 2 massive trees that I had always planned to get taken down, but only had that done mid August.
After those trees came down, I noticed we were getting generation 'clipped' at 2kwh, which was ~ 0.45kwh in the home, and ~ 1.5kwh to the grid, and it would jump to 4kwh or 5kwh etc when we used power in the home over that normal idle power use level of 0.45kwh . . . so, found out we had been put back onto FIXED EXPORTS of 1.5kw, which was flexible exports of up to 10kwh originally.
Short story (I'll update the other thread soon too), the solar co had NOT got the capability test done before the 6 month deadline, and signed off on the SAPN app, OR it failed that test, and SAPN put us onto fixed exports, without us knowing.
It turned out to be a software issue with SolarEdge, where they had configured for single phase instead of 3 phase.
We have lost a lot of self consumption generation through winter, now the problem is fixed (permanently) we can see we would have generated around 3 x what we did.
Your case ??
7.4kw with Fronious and PW2, I personally don't think you should have ANY bills !!
It depends a little, 7.4 of panels, what size inverter did they set you up with ??
5kw or 10kw inverter ??
Even if 5kw, you would just get 'clipping' through the day at the 5kw level through good days of sunshine, heck even on cloudy days if you have good aspect to the north and no shading, perhaps further north in Oz than we are in Adelaide. (A lot of factors determines that 'bad day' production.)
I'm not sure what you should do, but the solar co is responsible for getting that set up correctly, make sure they have it optimised, pass all tests required with the power supplier and power retailer (AGL), and have some pride in their workmanship !!
If that installer won't come out, try finding an independent local solar install inspector, they should be able to go through and do a thorough look through.
Take a look at this video that came up on my YT feed the other day, a good installer in QLD, talking with a good install inspector from Vic . . . https://www.youtube.com/watch?v=CpRmJQA6iX4
Note, some states have to have inspections after installs, some states don't.
Even a good solar co in your area should do an inspection, check wiring and settings throughout, and find out what's going on.
Once you have the inspection info, and any faults found, you MIGHT be able to get some compensation from the solar co, legal threat might be needed . . . or at least give them a few 'reviews' online, and AGL MIGHT be able to work out what was really the picture with the data of that period (how long has it been going on ?), and possibly do some adjusting . . . wouldn't hold my breath, after all they go on the power supplier data from the meters, but between them something might be possible.
At least you can know going forward you are getting the best possible from your solar / battery.
Good luck and keep us updated.
