Earlier this year, the International Energy Agency Photovoltaic Power System Programme (IEA PVPS) published a new report on the “Analysis of Long-Term Performance of PV Systems. This is the fourth of five critical reports, which are designed to establish a landmark in PV Performance and Reliability assessment, and build on the reputation of independence and quality of the IEA PVPS programme since 1993. We’re delighted to present an overview of the essential aspects of the study.
The quality and reliability of PV systems remains at the core of discussions about PV competitiveness. In the quest for competitiveness of PV electricity, consistent and predictable performance is expected to reduce PV financing costs and therefore, the cost of PV electricity.
Following four years of PV systems performance and reliability research, the IEA PVPS programme’s Task 13 has begun delivery on a series of five reports summarising these years of intensive research activities. These reports focus on several aspects of PV performance and reliability and cover the main aspects of quality-oriented activities in the PV sector.
Long-term performance of PV modules
The first three reports published focused on PV performance and the impact of PV module failure, for both crystalline silicon and thin-film technologies. They showed that the question of quality and reliability can be managed in a scientific way and that in recent years much progress has been made, in parallel with the growth of the PV markets and industry.
This fourth report investigates data supplied from installed operating PV plants in different countries in order to improve understanding of efficiency and reliability issues of current state-of-the-art PV systems.
The report concludes that PV systems installed in recent years are in general “delivering what the salesman says”, with country differences in annual yield that can well be explained by irradiation or climate zone differences. Based on the analysis of more than 600 PV plants in key countries around the world, the report also identifies numerous root causes of faults that lead to system downtime or low efficiency, expressed by a low overall Performance Ratio.
