With 11,000 Mw of generation off line and operating reserves below 5%, the California Independent System Wednesday took the unusual step of declaring a Stage 2 electrical emergency at 7 a.m. Pacific Standard Time, shortly after issuing a Stage 1 electrical emergency at 6:20 a.m.
The ISO attributed the early Stage 2 emergency declaration to an increased demand for power Wednesday morning, about 1,000 Mw statewide above Tuesday's 7 a.m. usage. The Stage 2 alert is in effect until noon, but the ISO said it expects to maintain stability of the transmission system without asking utilities to activate voluntary load management programs.
This is the third day in a row the ISO has called a Stage 2 emergency. With demand across the California ISO control area expected to peak at 34,226 Mw at 6 p.m., the ISO said the Stage 1 electricity emergency will remain in effect until 10 p.m.
More than 11,000 Mw remain off line, including an unusually high number categorized as forced outages, the ISO reported. Several power plants are off line for scheduled maintenance or because of expired air-emission credits. Additionally, power imports from the Northwest again are down today, Cal-ISO said.
In coordination with the California Public Utilities Commission, the ISO began on site inspections Tuesday night of all power plants reporting unplanned outages have forced shutdowns.
The ISO put out a call for 3,000 Mw of power Wednesday as supplies remain tight throughout the US West and Northwest. For the second day in a row, the grid operator asked California residents to delay turning on holiday lights until 7 p.m. when peak demand on the electrical system has subsided.
ISO officials have warned should the situation worsen for any reason, and power reserves drop below 1.5%, it will have to declare a Stage 3 emergency, which has never occurred statewide in California. The ISO would direct utilities to shed load resulting in involuntary rotating blackouts for blocks of customers across their service areas until sufficient reserve levels are achieved.