2026 Volume 22 Issue 3 Pages 168-181
Maintaining the functionality of electrical equipment during power outages has emerged as a critical issue. This study examines a damage cost estimation process for service interruptions of electrical equipment caused by natural disaster-induced power outages. The methodology elaborates on the procedures outlined in the JEMA “Cost-Benefit Analysis Guidance for Electrical Equipment” by establishing the causal processes and conditions linking equipment malfunction to incurred damages. Based on this process, the study examined the air conditioning and refrigeration function damages in factories, schools, and hospitals, focusing on the initial hours following the outage based on statistical data. Then, the study estimated both human damage costs—such as decreased productivity and health deterioration due to thermal discomfort—and property damage costs—such as quality degradation of temperature-sensitive goods—resulting from the loss of air conditioning and refrigeration functions during outages. These damage costs were further assessed by economic loss per unit of unserved energy (JPY/kWh). The results revealed the timing and magnitude of damage costs, categorized by type and affected asset. The estimation results are used to validate the process and identify key challenges in damage cost quantification, leading to a discussion of future directions for methodological improvement.
