@inproceedings{24550,
  abstract     = {{Efficiencies and energy yields of microinverters available on the market during 2014‒2021 have been 
measured, compared, and ranked. Conversion efficiencies as a function of load have been measured indoors with high 
accuracy and ranked according to Euro- and CEC weightings. Energy yields have been measured outdoors via 
identical and calibrated crystalline silicon PV modules of 215 Wp (until 2020) and 360 Wp (starting 2021). Inverters 
with two inputs have been fed by two of those modules. DC input, AC power output and energy yield of each microinverter have been recorded by individual calibrated electricity meters. CEC and EU efficiency rankings have been 
computed and compared. To assess the influence of PV module size, two extremes have been investigated: A rather 
small module with 215 Wp - as it has been used 10 years ago, and a brand-new module (2021) offering 360 Wp. Both 
types of modules contain 60 solar cells in series connection. Appling the low-power modules, the challenge for the 
different micro-inverters has been during weak-light conditions, using the high-power modules, some inverters 
temporarily reach their power limits and yield is reduced. A method using a reference configuration of inverter & 
module and a linear equation y = ax + b resulting in the actual yield, any module & inverter configuration can be 
characterized by just the coefficients a and b.}},
  author       = {{Krauter, Stefan and Bendfeld, Jörg}},
  booktitle    = {{Proceedings of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC 2021)}},
  isbn         = {{3-936338-78-7}},
  keywords     = {{AC-modules, Microinverter, Power Conditioning, Efficiency, Yield, PV module size, saturation, performance}},
  pages        = {{659 -- 663}},
  title        = {{{Module-Inverters (Microinverters): Influence of Module Size on Conversion Efficiencies and Energy Yields}}},
  doi          = {{10.4229/EUPVSEC20212021-4CO.3.4}},
  year         = {{2021}},
}

@inproceedings{18387,
  abstract     = {{ 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.}},
  author       = {{Krauter, Stefan and Bendfeld, Jörg}},
  booktitle    = {{Proceedings of the EU PVSEC 2020 }},
  issn         = {{3-936338-73-6}},
  keywords     = {{AC-modules, Microinverter, Power Conditioning, Thermal Performance, Ventilation, Stability, Efficiency, Yield}},
  location     = {{online}},
  pages        = {{1179 -- 1180}},
  title        = {{{Elevated Temperatures Affecting Efficiency, Overall Performance and Energy Yield of PV Microinverters}}},
  doi          = {{10.4229/EUPVSEC20202020-4AV.3.6}},
  year         = {{2020}},
}