“...and during the winter I bank a couple of kwh per day for cloudy days, or summer use.”
Must be some massive batteries you have. What kind ?
Your correct it does take some massive batteries if solar power is the only source of electrical energy. And I’ve done exactly that in the case of some remote communications site installations. Perhaps I failed to explain that I bank the power as CREDIT with the utility. IOW, any energy I produce in excess of my demand, is credited through a procedure called Net Metering, and reconcilled annually. So I basically bank the excess generated power on the utility books as credit toward consumption. With regard to batteries, Google communications batteries, for battery types and sizes. I’m not currently trying to run my house on backup batteries.