An Analysis of Reliability for Photovoltaic Systems on the Field Test Project for Photovoltaic in Japan

To develop a Photovoltaic (PV) module and cell efficiency are not only important, but also improving PV system performances is the significant technology. The long term reliability is one of the most important in PV systems’ performances. In Japan, NEDO (New Energy and Industrial Technology Development Organization) has organized “Field test (FT) project in Japan” from FY 1992 up to now. The user of PV systems in the project cooperates for collecting monitoring data and reports the information of maintenance and some failures of PV systems for four years. In this paper, the failures and maintenance information are reported by using MTBF, MTTR, and so on. Moreover, thje power conditioner is suspended by some protection or other reason — it is not failure, and the power conditioner can be restarted-which are obtained by PV system user’s reports.