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A 368-kWp Grid-Connected PV System: Known and Hidden Losses
G.H. Yordanov, F. Smolders, A. Olaerts, G. Verbeek, K. Baert, J. Driesen
Monitoring, Software, System Performance, Loss Analysis, Visualization
PV System Performance and Integration
Subtopic: Design and Operation of PV Systems
Event: 33rd European Photovoltaic Solar Energy Conference and Exhibition
Session: 6BO.7.3
1909 - 1914
ISBN: 3-936338-47-7
Paper DOI: 10.4229/EUPVSEC20172017-6BO.7.3
0,00 EUR
Document(s): paper, presentation


We present a method for real-time analysis and overall evaluation of some avoidable losses in large gridconnected PV systems. Plane-of-array (PoA) irradiance for each orientation is not required. For the 368.5-kWp flatroof PV system at EnergyVille with modules facing South, East, West, and North (tilted at 10° from horizontal), we estimated 8.9% ‘avoidable’ losses of which 2.1% due to inverter downtime including breakdown and another 6.8% shading and mismatch losses between April 22, 2016 and April 21, 2017. String undersizing losses were identified for one of the inverters in the form of systematic underperformance by about 8%. Each sub-array’s performance is compared to that of a non-shaded reference with the same orientation(s). We term as ‘ideal’ the operating conditions of the references. Plots of the relative array performance reveal the evolution of shading and other non-common-mode losses in the course of each day. Clear-sky comparisons are ideal for studying the shading loss evolution in the course of the day during different parts of the year, but also overcast days can reveal inverter or PV array issues at low input powers. Global horizontal irradiance (GHI) logging is therefore a minimum requirement. The method can be integrated in commercial PV-system monitoring software.