PVRessQ!: a research activity on reliability of PV systems from an user's viewpoint in Japan

In Japan, because both the government and PV industries have not been interested in operation and maintenance of PV system, almost all the PV users, number of which may be over 500,000, never knows troubles and/or risks which may happen to their PV systems during long-term operation. In 2006, author started "PVRessQ! (PV - Reliable, Safe and Sustainable Quality!)" activity in Japan. This activity has two action items: 1) field survey of existing residential PV systems to find troubles/failures and 2) statistical analysis by collecting trouble records from the PV users. In this paper, recent topics from this activity are introduced.