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Elevated Temperatures Affecting Efficiency, Overall Performance and Energy Yield of PV Microinverters
S. Krauter, J. Bendfeld
Power Conditioning, Thermal Performance, Ventilation, Microinverter, AC Module
Photovoltaic Modules and BoS Components
Subtopic: Inverters and Balance of System Components
Event: 37th European Photovoltaic Solar Energy Conference and Exhibition
Session: 4AV.3.6
1179 - 1180
ISBN: 3-936338-73-6
Paper DOI: 10.4229/EUPVSEC20202020-4AV.3.6
0,00 EUR
Document(s): paper


During comparative measurements of different PV microinverters, two yield issues came up that could not be explored via conventional efficiency measurements, but do have a significant impact on electrical energy yield: First category of issues are either sluggish or nervously acting maximum–power–point–tracking devices, which lead to reduced energy yields. The other category of issues is thermal: As a first explanation for observed reduced energy yields, it has been assumed that the conversion efficiency degrades at higher operating temperatures. This matter has been investigated in this article: A change in conversion efficiency could not be observed for elevated operation temperatures up to 50°C, despite high-precision and repeated measurements. But it was found that some inverters temporarily interrupted (or entirely stopped) operation after long periods of running at high temperatures. Also, a reduction in potential maximum power output has been detected for those inverters. Summarizing: With a high degree of certainty it can be stated that those reported yield losses have been caused by the temporary shutdowns and power limitations of the inverters.