Hi, I'm pre-empting the SAP calcs by modelling the expected solar gain - prior to any external shading being installed and would appreciate input re any errors in my approach.   I've used PVGIS to estimate the kwh / m2 for my location using a PV panel angle of 90 degrees and azimuth of 45 (SW) to simulate the sun hitting the windows. Of the two satellite datasets available I used the one with higher values (~5% higher)   This gives me the monthly kWh values (1st column)