I have 38 panels installed in three different directions East,South and West, so I never will reach the 21 kw peak. But production starts at 7.00 am till around 5.00 pm, let say 10 hours production. If I run my Air con's, Pool Pump , charge my EV with 5 kwh plus I have my 3 x 10kwh Batteries charged from 50% after night consumption to 100% I have at the end of the day appr. 85 kw produced. But off course I don't charge my Car every day.
I general the System looks a bit oversized, but if you have a cloudy day I still can run all my Equipment , charge my Car and have full Batteries in the evening for the night.
For Panels I have 550W and 580W Longi Panels, 2 x Deye 10 KW Hybrid Inverters and 3 x LV Topsun 10 kwh Batteries.