ICC calculations incorrect in Utility Mode when Solar panels are running

[Don]

This morning I struggled to charge my batteries from solar panels due to a lot of clouds around. The wife kept pestering when she could get going cleaning the house. She wants to start washing machine, tumble dryer, dishwasher and vacuum cleaner. I knew once the all start running, I will never get my batteries charged. I gave in and said ok, I will switch to grid. With Axpert setting 16 set to 050, at least I can charge my batteries from solar panels while the wife cleans the house on grid power.

I nearly fell off my chair when I had a look at the dashboard. It showed I had 3613 W produced from my solar panels which was charging my batteries 3632 W. That was close enough and made sense. Then I had a look at what was coming in from the Grid = 4756 W, with my load only sitting at 1088 W. That does not make sense. Coming in is Grid and Solar = 8369 W. What get used is Battery charging and House load = 4720 W. The difference between what is coming in to what is being used = 3649. That is close to what the panels were producing.

I then realised that in Utility (Grid) mode, all the power that gets produced by the solar panels, gets added to the Grid power. Every time the Solar panels sees some sun and climbs by 2000W, so does the Grid Power, without a change in load. The Grid Power produced during the day in Utility mode, will therefore overstate the Grid usage by what was produced by the Solar panels. My grid usage for the day stands at about 6.4 kWh for the day. About half of that power was produced by my Solar panels. No wonder my figures looks bad on PVOutput, lol. There are some double accounting in those figures.   

Edit: Looking at the picture again, the Solar Watts line should not drop to 0, just because I switched to Grid mode. If any power gets produced from Solar panels, it is because there is a Solar Load requirement and in this case, only Solar panels can charge batteries. It therefore should be the same as the Battery charging requirement, unless I don't understand Solar Watts correctly. And the Grid Watts line should be the same or close to the Load requirement. 

[Guest]

Hi Don

Yes that looks incorrect. Let me see what can be the problem. I know with the Axpert 3kw there is no way to detect after hours when no pv is avail what are you charging and add the watts to your total use. The Axpert 5kw does return it. Thanks for pointing out that there is a problem. I have a Infini and we run differently as the Axpert. The only way to know if i do get some feedback from the user

Sent from my SM-G920F using Tapatalk

[Don]

Thanks Manie. I assume there is only one application for all three inverters. If there are some differences between the 3kVa, 5kVa and Infini, maybe a one fits all solution may have to be broken up into 3 different solutions to make them more inverter specific, with different input and output parameters. You fix something on the one and break something on the other. Future updates will then have to be be inverter specific, i.e. 5kVa only, if you only make a change to the 5kVa inverters. 

[Guest]

Please let me know if it is fixed. Lets test it tommorow and see

Sent from my SM-G920F using Tapatalk

[Don]

Hi Manie,

I only realised now that I never replied and gave feedback. Sorry for only replying now.

Yes, it is fixed. Thank you very much. The grid watts no longer goes up when the PV watts increases. It is logging as it should. The Solar Watts graph still confuses me at times when I switch to Grid and there is PV watts coming off the panels, charging my batteries, but no Solar Watts. But I also understand that when running in parallel, you get one set of outputs and if I have different battery charging priority settings on my inverters, it becomes confusing. I even confuse myself, haha.

Thank you Manie for fixing it the same day.

[Guest]

Hi Don

I really think we need to remove it as it confuse almost everyone, Also with the infini it is difficult calculate Solar Watts . @cvzyl  and me had a discussion a few months back and the solution that he had was for me better.  

[Don]

Yes, I agree. You have a load that either comes from grid, pv, batteries or a combination of those. You throw solar watts in there, it gets confusing.