title: Microinverter Thermal Performance in the Real-World: Measurements and Modeling.
abstract: Real-world performance, durability and reliability of microinverters are critical concerns for microinverter-equipped photovoltaic systems. We conducted a data-driven study of the thermal performance of 24 new microinverters (Enphase M215) connected to 8 different brands of PV modules on dual-axis trackers at the Solar Durability and Lifetime Extension (SDLE) SunFarm at Case Western Reserve University, based on minute by minute power and thermal data from the microinverters and PV modules along with insolation and environmental data from July through October 2013. The analysis shows the strengths of the associations of microinverter temperature with ambient temperature, PV module temperature, irradiance and AC power of the PV systems. The importance of the covariates are rank ordered. A multiple regression model was developed and tested based on stable solar noon-time data, which gives both an overall function that predicts the temperature of microinverters under typical local conditions, and coefficients adjustments reecting refined prediction of the microinverter temperature connected to the 8 brands of PV modules in the study. The model allows for prediction of internal temperature for the Enphase M215 given similar climatic condition and can be expanded to predict microinverter temperature in fixed-rack and roof-top PV systems. This study is foundational in that similar models built on later stage data in the life of a device could reveal potential influencing factors in performance degradation.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America; Solar Durability and Lifetime Extension (SDLE) Center, Case Western Reserve University, Cleveland, Ohio, United States of America.
authors.forename: Mohammad Akram
authors.initials: MA
authors.lastname: Hossain
authors.affiliation: Solar Durability and Lifetime Extension (SDLE) Center, Case Western Reserve University, Cleveland, Ohio, United States of America; Center for Statistical Research, Computing and Collaboration, Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States of America.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Solar Durability and Lifetime Extension (SDLE) Center, Case Western Reserve University, Cleveland, Ohio, United States of America; Department of Physics, Case Western Reserve University, Cleveland, Ohio, United States of America.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Peshek
authors.affiliation: Underwriters Laboratories, Northbrook, Illinois, United States of America.
authors.forename: Liang
authors.initials: L
authors.lastname: Ji
authors.affiliation: Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America.
authors.forename: Alexis R
authors.initials: AR
authors.lastname: Abramson
authors.affiliation: Solar Durability and Lifetime Extension (SDLE) Center, Case Western Reserve University, Cleveland, Ohio, United States of America; Department of Material Science and Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America; Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America; Department of Physics, Case Western Reserve University, Cleveland, Ohio, United States of America.
authors.forename: Roger H
authors.initials: RH
authors.lastname: French
mesh_terms: D011211:Electric Power Supplies; D004867:Equipment Design; D006358:Hot Temperature; D008962:Models, Theoretical; D012044:Regression Analysis; D012993:Solar Energy; D013472:Sunlight; D013696:Temperature; D013997:Time Factors