SunPeek Open-Source Software for ISO 24194 Performance Assessment and Monitoring of Large-Scale Solar Thermal Plants

ISO 24194:2022, the first standard specifically designed to assess the operational performance of solar thermal collector arrays, is likely to have substantial impact on the entire solar thermal industry. This standard introduces the Power Check, a method that can be used for monitoring ongoing plant operation and for checking performance guarantees. However, its practical use is presently limited, as initial applications indicate a need for clarification, and it exists as a mere paper description, rendering it less accessible for plant designers and operators. Furthermore, any implementation necessitates practical decisions regarding data handling and algorithm implementation. Closed-source implementations, lacking a traceable and transparent framework, could lead to inconsistent results. To address these issues, this paper introduces SunPeek, an open-source software that provides a reference implementation of the ISO 24194 Power Check. SunPeek is freely accessible for both scientific and commercial purposes. This paper also discusses existing limitations of ISO 24194 and showcases five examples of SunPeek applied to real-life solar thermal plants. This underscores potential practical challenges, such as handling stagnation events, and highlights methodological progress, such as improved data filtering for performance analyses. The findings and applications indicate SunPeek’s usability and the high potential for ISO 24194-based performance monitoring of solar thermal plants.