Improved precision of the outdoor performance measurements of photovoltaic modules by using the photovoltaic irradiance sensor. (15th November 2020)

• Record Type: Journal Article
• Authors: Hishikawa, Yoshihiro; Higa, Michiya; Takenouchi, Takakazu; Ueda, Yuzuru; Nishioka, Kensuke; Kobayashi, Tomonao; Minemoto, Takashi; Taniguchi, Hiroshi; Wakabayashi, Hajime; Yoshita, Masahiro
• Is Part Of: Solar energy. Volume 211(2020)
• Page Start: 82
• Page End: 89
• Publication Date: 2020-11-15
• Subjects: I-V curve -- Outdoor -- Temperature coefficient -- Temperature correction -- I-V translation -- Irradiance correction; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2020.09.002
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Precise outdoor performance measurement is achieved even under unstable irradiance. The solar irradiance was measured with a PV module irradiance sensor (PVMS). The I-V curves were corrected for temperature by a new translation formula. The present results are useful for improving onsite measurement precision. Abstract: Highly precise outdoor current-voltage ( I-V ) curve measurement of crystalline silicon photovoltaic (PV) modules has been achieved, by monitoring the solar irradiance with a PV module irradiance sensor (PVMS), measuring the curves in 0.2–0.5 s, and filtering out the data affected by spatial nonuniformity of irradiance. The I-V curves were corrected for temperature by using a recently developed translation formula. Good reproducibility in the short circuit current I SC, open circuit voltage V OC, and maximum power P max measurements was confirmed, based on repeated measurements for one week. Small values of relative standard deviation σ, i.e., 0.1–0.23% and 0.24–0.42% for the I SC /GPVMS and P max /GPVMS, respectively, were confirmed even on partially sunny days and cloudy days when the solar irradiance is very unstable. Here, GPVMS denotes the irradiance measured by using a PVMS. The values of σ for various kinds of commercial crystalline silicon modules, including the p-type BSF, p-type PERC, n-type backside contact and silicon heterojunction, were also investigated in longer periods including different seasons of the year, which were 0.1–0.5% and 0.5–1.3% in the irradiance ranges of 0.9–1.1 kW/m 2 and 0.3–0.5 kW/m 2, respectively. The results have demonstrated that precise outdoor I-V curve measurements are possible in wide range of irradiance under various weather conditions. They are useful for improving the throughput and accuracy of onsite I-V measurements in operation and maintenance. Possible sources of residual measurement error and methods to further improve the precision are also discussed.