Potential Induced Degradation (PID) is a phenomenon that causes photovoltaic cells to lose efficiency due to the presence of eddy currents. The presence of leakage currents alters the photovoltaic cells inside a module. These currents appear when the module frame (or its immediate environment) is at a much higher potential than the cells.
The industrialization of photovoltaic modules and their evolution have favored this phenomenon, which is more common in Europe than in the United States. PID can be described as the rapid degradation of a photovoltaic module, leading to significant economic losses in the solar photovoltaic industry.
Following a presentation of the SID concept, the causes and aggravating factors at cell, module and plant level, as well as the means of identifying SID, possible overlaps and their impacts, are examined.
Historical overview
1839 – By immersing an electrode in a conductive solution exposed to light, Antoine Becquerel and his son Edmond discovered the photovoltaic effect
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1921 – Albert Einstein receives the Nobel Prize in Physics for being the first to explain the photoelectric effect in 1905.
1923 – Robert Andrews Millikan also wins the Nobel Prize in Physics for his work confirming Albert Einstein's predictions.
1977 – Worldwide installed photovoltaic capacity reaches 500 kilowatts (kW).
1978 – The JPL, a NASA space research center in California, publishes the effect of a frame-cell voltage on the performance of photovoltaic cells, the first publication of the PID effect
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1999 – Installed photovoltaic capacity exceeds 1 Gigawatt (GW).
2010 – The former German module manufacturer Solon introduces the term Potential-Induced Degradation