Heavy Use Takes Its Toll on Two Power Plants

Two Southern California power plants failed Friday, pushing the state’s power grid into a Stage 1 emergency--evidence that the electricity plants supplying California are beginning to falter under the strain of running flat out for several days with no maintenance.

Failure of a 400-megawatt power plant in Northern California Thursday brought a more serious Stage 2 emergency, as electricity reserves fell below 5%. A Stage 1 is declared when reserves drop below 7%.

A Stage 3 is declared when reserves fall below 1.5% and rolling blackouts become likely. California has never endured a Stage 3 but came dangerously close Tuesday and Wednesday, as heavy demand crashed into puny supplies. In a Stage 3, blackouts of rotating blocks of customers for about an hour are necessary to avoid a system failure, which would leave more customers in the dark for several hours.

The California Independent System Operator, which runs the power grid for most of the state, has kept power generators and transmission lines under a “no-touch” order for five days because of heavy demand. Such a directive, which has been given at least 17 times this year, forbids all but emergency repairs.

Electricity usage peaked near 42,000 megawatts Friday afternoon, much lower than the more than 45,000 megawatts that would have been required Tuesday if the state’s large investor-owned utilities had not cut power to certain big customers under prearranged contracts.

But the failure of the two plants Friday pulled 550 megawatts off the grid, or enough to supply about 550,000 homes, causing the electricity emergency.

The Northern California plant that failed Thursday was operating again Friday.

“This very much demonstrates the fact that we have been running this system hard for more than two months,” Cal-ISO spokesman Patrick Dorinson said. “That’s taken a toll, not only on the power plants, but also on the operators and everyone else.”

Jan Smutny-Jones, chairman of the Cal-ISO board of governors and director of the Independent Energy Producers Assn., said 64% of the electricity-generating plants once owned by the state’s big utilities are 30 years old or older.

“For a power plant, that is pretty old, and they’re running as well as can be expected,” he said. “While we need to modernize the electricity infrastructure in California, I don’t think it’s time to hit the panic button.”