One worker for the Independent System Operator for California, USA has been fired, and two more suspended for triggering rotating blackouts that led to nearly 1 million southern Californians losing power on April 1. The ISO said that the disciplinary hearings had taken place earlier this month after a plant shutdown caused rotating outages in 17 counties from the Mexican border into Orange County, but only announced the outcome yesterday.
ISO spokeswoman Stephanie McCorkle said that the three employees were involved in two major errors. First, they acceded to a request from a scheduling coordinator of the Otay Mesa plant, which sells its power to SDG&E, to shut down after midnight. She did not say why the scheduling coordinator, who works independently of the plant, asked for the shutdown, but said that such requests are not uncommon because the period between midnight and 5am typically has a low demand for electricity.
At the time, Otay Mesa was the only plant fully operating in San Diego County. As a result, the shutdown at Otay Mesa put the power system in violation of rules that require SDG&E to derive at least a quarter of its power from local generators.
McCorkle said that the second error consisted of “overcorrecting” for the shutdown by calling for a rotating outage that affected nearly 1 million people. According to an ISO investigation, the three workers incorrectly thought they were under a federal deadline to resolve the issue within 30 minutes, prompting them to take immediate action. However, the federal deadline did not apply in this case, meaning that the workers had enough time to avoid the blackouts.
To prevent a repetition, the ISO is retraining workers and implementing procedures to clarify what steps should be taken in a similar situation and changing its alarm system to warn of a lack of generation before a major plant is shut down.