Monitoring of solar cogenerative PVT power plants: Overview and a practical example

This paper introduces the topic of management and monitoring of photovoltaic/thermal (PVT) systems, highlighting the differences respect to photovoltaic (PV) and solar thermal (ST) systems. A PVT module is a collector that produces at the same time both electrical and thermal energy. Thereby, the monitoring architecture of a non concentrating PVT system, realised with crystalline silicon cells liquid-cooled, is described.In addition, a web application allows the on-line monitoring and control of that PVT system. Thus, daily reports of the remote PVT installations are elaborated and sent to the system operator. These data can be analysed off-line to calculate both energy performance indices and statistical values. Historical data analysis is useful not only to optimize the operation of the PVT system but also to design its retrofit. To check the effectiveness of the proposed remote monitoring system, the performances of two twin stand-alone systems a PVT plant, based on a patented PVT collector named TESPI, and a PV plant have been evaluated through an experimental campaign of measurements.The two twin systems (one PV and the other PVT) are installed in Enna (Italy), where typical Mediterranean climate is present. During the survey both electrical and thermal critical operating conditions have been detected such as: deep discharge of batteries, optical losses and stagnation.