Stefan Krauter, Mohammed J. Salhi, Sandra Schroer, Rolf Hanitsch
Bibliographic info:
Building Simulation, 7, 2001, Rio de Janeiro, Brazil, p. 619-626

Most photovoltaic (PV) facades are built as curtain facades in front of thermally insulated buildings with air ducts in between. This causes additional costs for support    structure    and    installation,    while    heat dissipation from the solar cells is often not optimal. Measurements carried out are facing both concerns: Integration of a thermal insulating layer (which meets the latest German heat preserving regulation WSV 95) into the PV facade plus additional cooling by active ventilation   or   water   flow.   Simulation   of   different system  configurations  by  an  energy  flow  balance model  were  compared  to  actual  measurements  and showed  relative  small  deviations.  Active  ventilation at conventional curtain PV facades allows a reduction of cell operating temperatures of 18 K, resulting in an 8%  increase  in  electrical  energy  output  at  an  air velocity of about 2 m/s. Cell temperatures increase by 20.7  K  at  thermal  insulating  PV  facade  elements (TIPVE) without cooling, which causes a 9.3% lossof electrical yield, but installation costs can be reduced by 20% (all related to a conventional PV curtain plus a heat  insulating  facade  at  a  building).  HYTIPVE,  a hybrid    thermal    insulating    PV    facade    element combined with a  water-cooling system,  which  could also serve for hot water heating, lowers operating cell temperature by 20 K and increases electrical yield by 9%  (referred  to  conventional  curtain  PV  facades). Further  economic  investigations  of  such  HYTIPVE including  operational  costs  and  substitution   effect related to the yield are on the way.