Hi,

For this question, first you have to figure out which load is you exactly your main requirement (Electricity or hot/warm water？).

if it is electricity, you need to calculate PV area based on the electricity efficiency of the PV plate, then heat load can be determined by the PV-T thermal efficiency roughly.

If it is hot water, just goes with the reverse way, same as above.

As Tingting has said, more information is needed if we are to answer this question.