Close roof-mounted system temperature estimation for compliance to IEC TS 63126

• Published in: Solar energy materials and solar cells 2024-09, Vol.275, p.112987, Article 112987
• Main Authors: Kempe, Michael D., Ovaitt, Silvana, Springer, Martin, Brown, Matthew, Jordan, Dirk C., Sekulic, William, O'Brien, Colleen, Jaubert, Jean-Nicolas, Yu, Yuanjie, Oh, Jaewon, Tamizhmani, Govindasamy, Li, Bo
• Format: Article
• Language: English
• Subjects: BAPV; BIPV; High-temperature; IEC TS 63126; Open-rack; Photovoltaic; Roof-mount; SOLAR ENERGY
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2024.112987

When photovoltaic (PV) modules are installed on rooftops, the module temperature depends primarily on the geographic location and the mounting configuration. If the mounting structure does not provide sufficient airflow in a hot environment, the 98th percentile temperature will exceed 70 °C, which according to IEC TS 63126 ED. 1, requires higher levels of thermal stability testing. However, there is no clear way to determine the temperature level needed for a particular location and system design. In this work, we identify a relationship between the module standoff to the rooftop and the module temperature and propose methods to describe a minimum standoff for typical PV modules in a simple mounting configuration installed in a given location. For more complex system designs, we show how to determine an equivalent “effective standoff” that can be applied to generic calculations. Lastly, we show measurements and calculations from several systems to demonstrate how this method could work. •We developed a simplified method for photovoltaic module temperature estimation for high temperature installations.•An effective standoff distance for an arbitrary photovoltaic system can be determined and applied to generic maps.•The 98ᵗʰ percentile photovoltaic module system temperature must be below 70 °C or 80 °C to avoid additional tests.•The temperature of a module drops off exponentially with distance with a characteristic decay distance of 6.5 cm.•Most off the issues with compliance to IEC TS 63126 will occur for standoff distances of less than 5 or 10 cm.