Potential-Induced Degradation can be easily discovered by using EL images. Although it is possible to detect PID from EL images, it is necessary to perform IV measurement again to estimate how much the power of the mega solar is reduced by PID. The authors are investigating a method to quantitatively estimate the power from the EL image. In this study, we evaluated Rsh of the PID module on a cell-by-cell basis and verified that the power could be estimated only by adjusting Rsh. Next, the correlation between the light emission from the EL image and Rsh was examined, and the power was estimated using Rsh estimated from the EL image. As a result, we were able to estimate the power with an error rate of about 3%. In addition, we found that the power can be estimated more easily by binarizing the amount of light emitted from the EL image and estimating Rsh.