ABSTRACT
An existing office building has been retrofitted with a PV-system on each of the four vertical facades. The facades are facing north, south, east and west. The applied system consists of single-junction amorphous silicon modules. The paper presents monitoring data obtained from August 1999 to April 2000. Although the monitoring period is not yet adequate for a complete assessment of the performance of the PV-systems, some conclusions can be already drawn.
