On September 9, 2011, FERC and the North American Electric Reliability Corporation (“NERC”) announced they would work together to examine the September 8th power outage that affected more than 1 million customers in Southern California, Arizona and Northern Baja Mexico.  4,300 megawatts (“MW”) of load were lost when a technician removed a voltage-regulating capacitor bank from service in a North Gila, Arizona substation, and a 500kV transmission line from Phoenix into Southern California went out of service.

FERC and NERC announced that they will work with the Department of Energy, the Western Electricity Coordinating Council, state regulators in California and Arizona, and the companies involved to explore the causes of the outage. 

Gerry Cauley, president and chief executive officer of NERC stated, “Partnering brings together the expertise of both organization, and emphasizes the importance placed on reliability of the bulk power system.”  FERC Chairman Jon Wellinghoff announced the joint inquiry at the September 15, 2011 FERC Regular Meeting, and applauded the recent joint efforts of FERC and NERC concerning the Southwest outage of February 1-5, 2011 (see February 18, 2011 edition of the WER).

At the September 15, 2011 FERC Open Meeting, Commission staff presented a report by a similar task force charged with examining the February Southwest outage.  From February 1-5, 2011, 4.4 million electric customers in the Electric Reliability Council of Texas (“ERCOT”) and Western Electricity Coordinating Council (“WECC”) were affected, and over 50,000 gas customers in New Mexico, Arizona and Texas faced curtailed service.  The task force found that while ERCOT went through a similar cold weather event in 1989, the lessons learned were not used to prevent the February 2011 outages.  In total, over 250 electric generating units in ERCOT, WECC and the Southwest Power Pool experienced outages from February 1-5, 2011.  The largest problem causing outages was frozen sensing lines, then frozen equipment, water lines and valves.  The task force found that balancing authorities and reserve sharing groups must review distribution of reserves to make sure they are useable and deliverable during contingencies, considering transmission constraints, demands on reserve sharing resources and the possibility of simultaneous emergencies. The task force also recommended that balancing authorities improve communications during extreme weather events with transmission owners and operators, distribution providers and other market participants. 

The task force also examined the availability of the gas supply and found that additional gas storage capacity in Arizona and New Mexico could have worked to prevent “many” of the outages that occurred.  The task force found that the pipeline network, both interstate and intrastate, showed good flexibility in adjusting flows to meet demand and compensate for supply shortfalls.  Commission staff reiterated it is committed to working with NERC and Regional Entities to implement applicable recommendations before extreme weather arrives.

A copy of the September 9, 2011 announcement is available here.

A copy of the Southwest Cold Weather Event Staff Presentation is available here.