Effect of packing factor (the fraction of absorber plate area covered by the solar cells) on the -Long-term performance of a photovoltaic/thermal hot water system under the meteorological conditions of Malaysia has been simulated. In this study, the typical weather year file containing the weather parameters for Kuala Lumpur has been considered. The results indicate that for both glazed and unglazed conditions, the increment of the packing factor resulted in the decreasing solar fraction, whereas this effect for the coverless PV/T collectors was found sharper than the glazed ones. For polycrystalline and mono crystalline silicon cells, the maximum solar fraction was found in the polycrystallin cells, while the minimum one was obtained from the mono crystalline solar cells. Apparently, the curves followed the same pattern for the unglazed PV/T collectors.
