Hi @RadwaEzzat ,
Thank you for the attached files.
That component is very old (from November 2015). The error you get can be due to some bug which has already been fixed on the latest version (Ladybug 0.0.69).
I would advise you to look at this example file in order to understand how to use ‘PV SWH System size’ component. ‘PV SWH System size’ component will be the input for the ‘Photovoltaics Surface’ component.