Comparative study of different PV modules configuration reliability

One of the most promising source of renewable energy is the direct conversion of solar energy owing to the present state of achieved technology in manufacturing PV modules, their comprehensive cost and the high depletion in non-renewable energy sources. The reliability of stand alone PV systems becomes one of the major trends in the present design of such systems. The system configuration plays an important factor determining the overall system reliability. This paper emphasizes the existing manufactured modules and illustrates the reliability analysis of different system configurations. AC bus level connection using module integrated inverters vs. DC bus level connection, cabling losses shading effects are also examined. A case study is selected to calculate and compare the reliability of different system configuration using the analytical approach.

From the results presented in this paper the following concluding remarks can be made: 1) A module integrated inverter system potentially has much higher reliability than the other configurations, multiple inverters provide in-built redundancy failure of one PV module or inverter in a system with many inverters will have only an incremental effect on overall system performance. 2) The average useful life of the module integrated inverter is very long comparing with the other configurations. 3) Cable losses are reduced to the minimum using module integrated inverter, because in module integrated system the inverters are mounted on the back of each individual panel. 4) In module integrated system the impact of shading using module integrated inverter is lower. 5) Module integrated inverter system also provides enhanced modularity, new panels can be added easily at any time.