System performance loss due to LeTID

• Published in: Energy procedia Vol. 124; pp. 540 - 546
• Main Authors: Kersten, Friederike, Fertig, Fabian, Petter, Kai, Klöter, Bernhard, Herzog, Evelyn, Strobel, Matthias B., Heitmann, Johannes, Müller, Jörg W.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2017
• Subjects: light-induced degradation; mc-Si PERC; light-induced degradation; mc-Si PERC
• ISSN: 1876-6102; 1876-6102
• DOI: 10.1016/j.egypro.2017.09.260

If not adequately suppressed, Light and elevated Temperature Induced Degradation (LeTID) has been shown to cause severe degradation of multicrystalline (mc-Si) silicon solar cells and modules with passivated emitter and rear cell (PERC). Within this work, the system performance of LeTID-sensitive mc-Si modules is investigated when operated in temperate and mediterranean climates, and a correlation to predict the observed field performance based on accelerated laboratory testing is presented. Severe degradation induced by LeTID of up to 7% in maximum output power is detected after one thousand hours of laboratory testing, which is shown to correspond to ~ 3 years of field installation time in Cyprus. In contrast, LeTID-sensitive modules installed in Germany show a degradation of 2.5% within the same time period. Due to lower irradiance values and module temperature in Germany the LeTID rate is lower than in Cyprus. A significant dependence of system performance loss and energy yield due to LeTID on installation site is shown. Hence, the loss in system performance due to LeTID affects one-to-one the levelized cost of electricity (LCOE) compared to reference without LeTID. Furthermore, it is shown that LeTID in the field can be suppressed by applying Hanwha Q CELLS’ Q.ANTUM technology, independently of installation site.