ALUk

I have room for 2 or 3 more south facing could go on kitchen roof. then I have room for 4 or 5 west facing. I have a east facing roof but as it’s at the front of the bungalow I wasn’t going to fit panels on it. In the winter months I fill up my 200w battery bank with overnight off peak electricity. then on dull days of which there are many. I find more power coming from the battery than the house is using. the inverter consumes more that it produces. December photo attached.

I have 10x390w. Trina panels south facing on 1 MPPT. and 8 of the same laid flat on garage roof on second MPPT.

I have 10x390w. Trina panels south facing on 1 MPPT. and 8 of the same laid flat on garage roof on second MPPT. would like increase to 12 on each MPPT if possible?

good afternoon Living here in the uk the winter months can be a tad grim. So my 8kw sunsynk inverter is using most if not all the power just to keep itself running. id like to add more panels if possible. id like to put 12x390w panels on each MPPT When calculating the max voltage of a solar panel string.. what should I us? Maximum power voltage VMP or Open circuit Voltage. VOC Thanks in advance