As well as the technical design criteria, the performance of a stand-alone photovoltaic (PV) system depends on other variables, such as the solar radiation distribution and load profile. Different load profiles are encountered in stand-alone PV applications. Load profiles may vary from 24-h constant to only nighttime or oppositely only daytime load profiles. This article presents results of system performance simulations for analysing the effect of different load profiles on the system performance. The load demand used in this article is appropriate for an average residential application with an average 9.4kWh of daily energy demand. The loss-of-load probability (LLP) of the PV system is simulated for five different weekly load profiles and the results are examined based on techno-economic parameters, including the total system cost or alternatively the cost of electricity per kWh for a 20-year system lifetime. The results are drawn based on 1-year long hourly time-series solar radiation and ambient temperature data. (c) 2006 Published by Elsevier Ltd.