Microinverter Thermal Performance in the Real-World: Measurements and Modeling

Area of Science:

• Renewable Energy Engineering
• Photovoltaic Systems Analysis
• Thermal Performance Monitoring

Background:

• Microinverter performance, durability, and reliability are crucial for photovoltaic (PV) systems.
• Understanding thermal behavior is key to predicting long-term operational efficiency and lifespan.

Purpose of the Study:

• To investigate the thermal performance of Enphase M215 microinverters under real-world conditions.
• To identify key environmental and operational factors affecting microinverter temperature.
• To develop a predictive model for microinverter internal temperature.

Main Methods:

• A data-driven study using minute-by-minute power and thermal data from 24 microinverters and 8 PV module brands.
• Data collected over four months (July-October 2013) at the SDLE SunFarm, including insolation and environmental parameters.
• Development and testing of a multiple regression model using solar noon-time data.

Main Results:

• Microinverter temperature showed significant associations with ambient temperature, PV module temperature, irradiance, and AC power.
• A rank ordering of covariate importance was established.
• A multiple regression model was successfully developed to predict microinverter temperature, with adjustments for different PV module brands.

Conclusions:

• The developed model accurately predicts Enphase M215 microinverter temperature under specific climatic conditions.
• The model can be adapted for fixed-rack and roof-top PV systems.
• This foundational study provides a basis for future research on performance degradation using later-stage operational data.