Common Issues Affecting PV System Performance

Over the last few years more and more failures occur in old installed systems many of which could have been avoided. The main problem studied in this paper is the unexpected reduction of electricity production in photovoltaic parks after a few years of operation. In many photovoltaic parks the performance ratio (PR) has fallen below 80% while normally it should be a little over 90%. This reduction in energy production leads to an increase in the payback period of investment. This paper will also explore the causes of reduced production and ways to recover from the problems as well as improvements that can be made to increase energy production and reduce maintenance costs. Firstly, the basic theoretical concepts are presented and in the next part, the paper throws new light on the problems which occurred and the existing methods of their resolution.