Quality Assessment of Solar Panels

PVStatLab focuses on the quality assessment of solar panels.


According to the specifics of the photovoltaic market, quality control should be primarily based on acceptance sampling rules to control shipments for customers. Statistical quality control is of increasing importance, since ongoing research efforts aim at increasing both the physical and economic lifetime of photovoltaic modules, in order to cut costs of photovoltaic energy production. 


There is a longstanding discussion on possible module degradation that reduces the energy yield as time proceeds. Recent studies have shown that degradation of crystalline modules can negligible (around 0.1% per year) on a short time scale. However, various factors may lead to early aging, degradation and even defaults. Thus, the assessment of the modules at the time of delivery or shortly after mounting the modules provides a high level of certainty regarding their quality; in many cases such a quality assessment should be very informative for the first years of operation, in particular, if it is augmented by an additional inspection at a later time point.


The methodology favored by PVStatLab allows

  • to define what we mean by non-conforming modules taking into account acceptable tolerances,
  • to specify the quality requirements in terms of the fraction of non-conforming modules,
  • manufacturers and customers to control their error probabilities of a false decision.

For more information, see the AQL-RQL-methodology.