Inadequate planning and a lack of awareness of the electrical system led to 2.7 million customers in the Southwest being without power, according to a report released Tuesday morning.
Staff from the Federal Energy Regulatory Commission and North American Electric Reliability Corp. released a report of the Sept. 8 power outage that affected Arizona, Baja California and Southern California, including all of the Imperial Valley. The investigation began to look into what caused the outage and make recommendations to avoid similar situations in the future.
The potential impacts of the report and its finding is potentially millions of dollars in fines for the group that caused the massive outage. No results have yet been given.
The two energy regulatory groups determined those running the energy system were not prepared to ensure reliable operation and prevent cascading outages from one event, the loss of Arizona Public Service’s Hassayampa-North Gila 500-kilovolt transmission line, according to a press release from the agencies.
The line loss did not cause the blackout, but it did initiate a sequence of events that led to the blackout. For example, had operators reviewed and heeded their Real Time Contingency Analysis results prior to the loss of the Arizona line, they could have taken corrective actions, such as dispatching additional generation or shedding load to prevent a cascading outage.
One focus of the report is the possible impact of the Imperial Irrigation District’s protection system relays on certain transformers in the Coachella Valley that tripped open during the power outage, said General Manager Kevin Kelley.
Since the beginning the district has taken the position that the relays performed as they should have in order to prevent serious damage from the excessive power flows surging through the district’s system from the nearby power authorities.
The district denies any assertion that its relay operations led to the cascading effect associated with the outage, Kelley said. At the same time, it has taken several steps to mitigate against a repeat of the same circumstances to allow for an increase in emergency loading levels.
While the local utility district is still reviewing the report, it is committed to implementing any of the report’s recommendations “that will lead to greater visibility between and among this organization and neighboring balancing authorities,” Kelley said.
What is known is that IID restored service to its customers faster than the others affected in the region, within six hours of the power going out locally.
The report recommends transmission operators and balancing authorities improve how they plan for operations to account for the status of facilities outside their individual systems, the effect of external operations on their own systems and how operation of transmission facilities under 100 kilovolts can affect the reliability of the bulk power system.
“This report highlights the growing need for more coordination of grid operations in the West,” FERC Chairman Jon Wellinghoff said. “Implementing the recommendations in this report will assist in enhancing the planning and system awareness measures that are necessary to operate an efficiently integrated bulk power system, and reduce costs to consumers from these types of outages that could continue if operational efficiencies are not improved.”
Staff Writer Elizabeth Varin can be reached at email@example.com or 760-337-3441.
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