Thermal effects of microinverter placement on the performance of silicon photovoltaics

• Microinverters installed behind a PV panel can create a distinctive hot spot.
• Rotation of the microinverter removes the distinctive hot spot on the panel.
• Rotation of the microinverter allows the microinverter itself to run cooler.
• Rotated (cooler) microinverters operate at slightly higher efficiency.

Typical installation of a microinverter in a plane parallel position on the back side of a monocrystalline silicon photovoltaic (PV) panel can lead to differential heating of the PV cells immediately above the microinverter by as much as 4 °C. Rotation of the microinverter to a perpendicular position allows the microinverter itself to run cooler by about 4 °C and completely removes the distinctive heat signature on the panels. Because the thermal effects of the microinverters are significant for only two of the 72 cells on the panel, changes in DC power output from the panels are not detectable. However, lower microinverter temperatures increase microinverter efficiency by about 0.65%, such that overall AC power production is increased by about 0.09%. In addition to these small improvements to be gained by the repositioning of microinverters, there are also potential long-term concerns that nonuniform heating may lead to accelerated degradation in the affected area of the panel.

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