1.38 - Performance Monitoring

Performance monitoring of photovoltaic (PV) modules and systems allows the determination of their energy output and any operational issues over their lifetime. As PV systems have moved from demonstration of the technology to widespread commercial energy generation, the main purpose of the monitoring has also changed. This has resulted in new approaches and services meeting the requirements of the system owners. In the context of larger installer/operators, system monitoring is also used to close the cycle with system design improvements. It also includes the intermediate step of module monitoring, where the key component is analyzed for its specific energy yield. This knowledge is then used for sizing the systems appropriately. This article describes the principles of PV module and system monitoring and how this is achieved in practice.