A research group in Spain has demonstrated the technical feasibility of using repaired solar panels with satisfactory results. However, it also warned that there is an urgent need to define a protocol for evaluating the characteristics of a “viable” repaired panel.
A group of researchers led by the Spanish Center for Energy, Environment and Technological Research (CIEMAT) assessed the performance of 23 partially repaired crystalline silicon solar modules in a 12-year-old PV installation in Spain and found that these panels can operate with minimal costs. to lose.
“This study uses a comprehensive standardized approach,” the scientists explained. “It integrates visual inspection, electrical testing, electroluminescence imaging and thermal imaging techniques to thoroughly evaluate the functional status of these modules and define the nature and extent of defects that persist after repair.”
The test was carried out according to the IEC 61215 standard
Module errors were identified according to the following classification:
Through the visual inspections, the team found that the modules exhibited optical degradation due to delamination and discoloration of the encapsulant. Moreover, she has also established that
The IV Curve measurements showed that the modules showed no abnormalities, although a power reduction was detected, while electroluminescence (EL) imaging showed that approximately 73% of the panels showed microcracks and darker areas at the edge of the solar cells.
When they used infrared thermography, the researchers found that ‘strong hotspots’ were detected in 4.35% of the panels analyzed, while ‘light hotspots’ were identified in 74% of the modules. “In this latter group, we found that 47% had high temperatures in the junction boxes, which were due to diode activation and further energy dissipation,” she added.
Overall, the analysis showed that the most common defect in the repaired modules is moisture-induced degradation (MID), followed by cracked cells and disconnected areas within cells.
“However, despite the presence of defects, approximately 87% of these modules show a power degradation of less than 20%,” the scientists said. “This important finding suggests that the repaired modules successfully meet the manufacturer’s warranty criteria, indicating their potential for reuse.”
However, the group also warned that there is an urgent need to define a protocol for evaluating the characteristics of a “viable” repaired panel. “In addition, it is necessary to increase awareness regarding international standards and Cradle-to-Cradle certification as this has the potential to drive market demand for second-hand modules with improved sustainability and circularity features,” the report concluded.
Their findings are available in the article “Improving the durability of photovoltaic modules: defect analysis of partially repaired modules of Spanish PV installations”, published in the Magazine for cleaner production.
Another research team at CIEMAT recently developed a series of techniques to repair ribbon rail breaks in PV panels without resorting to expensive electroluminescence imaging.
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