A longitudinal research project of the Fraunhofer Institute for Solar Energy Systems Isee reveals that since 2017 the institute has measured less power on average in a solar module than promised by the manufacturer.
Research by the Fraunhofer Institute for Solar Energy Systems Isee (Fraunhofer Isee) has found a negative trend that between performance data of PV module manufacturers and the performance measurement of the Institute of the module since 2017.
Since 2012, the team has tested more than 70,000 solar modules in the calibration laboratory and analyzes 1,034 of the collected performance measurements from monocrystalline silicon modules under standardized conditions.
Analysis between 2012 and 2016 showed that measuring abnormalities between promised strength and performance were on average always less than 1%, with some positive deviations being measured. The results from 2016 showed the difference between the manufacturer’s power specifications and the measured power in the Laboratory of the Institute was on average 0.6%.
Since 2017 there has been a negative discrepancy between the specifications and results in the Laboratory of the Institute. The negative trend turned out to be particularly pronounced in the 2020 to 2023, culminating in an average power reduction of approximately 1.3% in 2023, with a positive deviation that was almost never observed.
Daniel Phillip, head of the characterization and reliability of the departmental module at Fraunhofer Isee, says that a slight trend removal was observed in 2024, but the average result still showed a capital reduction of 1.2% against the manufacturer’s specifications.
“If we assume that our data is representative of the German installation market, an average underperformance of 1.2% with an additional 16.2 GW in 2024 corresponds to a total output of approximately 195 MW,” added Phillip, which corresponds to the nominal output of one of the largest solar parks in Germany.
Fraunhofer says that the decrease between 2023 and 2024 suggests that production companies may have recognized the tendency to optimistic power reviews as a problem. “The findings also make clear how important a reliable, continuous and independent infrastructure is for the quality control of PV modules,” added Professor Andreas Bett, Institute Director at Fraunhofer ISE.
Fraunhofer says that the data in the study was filtered according to suitable criteria for the evaluation, with inconsistent data deleted and used further filters to exclude statistical distortions.
The analysis contains solar modules of only the top ten manufacturers in every respective year and only contains data from projects where the customer and the manufacturer were different, to achieve a result representative of Modulekopen.
This content is protected by copyright and may not be reused. If you want to work with us and reuse part of our content, please contact: editors@pv-magazine.com.
