“…After 1 day of PID testing, the P max / P max,0 value of the a‐Si, CIGS, and n‐type rear‐emitter c‐Si PV modules decreased to 0.23, 0.95, and 0.93, respectively. When the PID tests were 2 days long, however, the P max / P max,0 for the p‐type c‐Si and n‐type front‐emitter c‐Si PV modules decreased to 0.04 to 0.4 and 0.85, respectively. In contrast, the SHJ PV modules exhibited little degradation after the 2‐day‐long PID test.…”