Before & After
Without power for 94.2 minutes per year
1.22 service interruptions per year
Outages lasted 77 minutes per outage
Without power for 19.4 minutes per year
0.33 service interruptions per year
Outages lasted 59.5 minutes per outage
Overhead vs. Underground
System Average Interruption Duration Index (SAIDI) is the average outage duration for each customer served (in Minutes). System Average Interruption Frequency Index (SAIFI) is the average number of interruptions that a customer would experience. In both these measures, Underground (UG) utilities are shown to be much more reliable than Overhead (OH) utilities.
Overhead (OH) and Underground (UG) metrics that only include primary circuits, feeders and laterals.