Solar energy is considered as one of the major renewable energy sources and electricity generated from photovoltaic system involves zero green house gas emission and zero dependence on fossil fuel. However, the use of solar energy suffers from the challenge of ensuring steady flow of electric power particularly during the periods of low solar radiation. This has caused system designers to look into the reliability aspects of solar photovoltaic systems. One way of minimizing the impact of irregular power supply is by the inclusion of a storage unit so that the surplus energy generated during period of high solar radiation can be stored and utilized later during periods when solar radiation is low or absent. But, storage systems using batteries are an expensive proposition. It is of interest to system design engineers to examine just how much is gained in terms of reliability of power delivery at the cost of hardware failure of panel for solar PV systems operated with and without battery storage. The present paper attempts to investigate the changes in system reliability of a solar photovoltaic system under the cases of operation with and without adequate battery storage. Reliability estimation through Loss of load probability index is carried out using Monte Carlo Technique.