Berkeley Labs has released a report on electricity reliability on the United States. This study looked at reliability data collected by electricity distribution companies, and created two metrics.
- System Average Interruption Duration Index (SAIDI) which indicates the amount of time a customer is without power over the course of a year on average.
- System Average Interruption Frequency Index (SAIFI) which is the average total number of times a customer experiences a power interruption over the course of a year.
![Image](https://newscenter.lbl.gov/wp-content/uploads/sites/2/2015/08/Reliability-Cover-Final-628x813.jpg)