This European Standard is part of a set of standards on the method for calculation of system energy requirements and system efficiencies. The scope of this specific part is to standardise for photovoltaic systems: ? required inputs; ? calculation method; ? resulting outputs. The calculation method applies only to building integrated photovoltaic systems. The calculation method does not take into account: ? electrical storage; ? PV/thermal photovoltaic systems. The calculation method describes how to calculate the electricity production of photovoltaic systems. Primary energy savings and CO2 savings, which can be achieved by photovoltaic systems compared to other systems, are calculated according to prEN 15603. Standards linked to photovoltaic systems are listed in Annex A.