A still-unexplained explosion that rocked Calpine Corp.'s 648-MW natural gas-fired Russell City Energy Center in the San Francisco Bay area in late May has left the eight-year-old plant out of service for an undetermined period of time, complicating California's increasingly precarious grid reliability picture for this summer.
The loss of the facility, which delivers power to PG&E Corp. operating arm Pacific Gas and Electric Co. under a 10-year contract, contributed to the California ISO's July 1 call for additional capacity to ensure the lights stay on in the nation's largest state economy, along with depleted hydroelectric dams impacted by severe drought and delays at new resources scheduled to come online this summer.
An affiliate of Calpine in June asked the California Energy Commission, which is responsible for certifying thermal power plants, for permission to install temporary safety modifications to the project's steam turbine condenser to allow the combined-cycle facility to operate in simple-cycle mode at 300 MW to 350 MW of capacity. The project would also offer frequency and voltage support. If approved, the plant could be back in operation at that reduced capacity for the August and September time frame, the Calpine affiliate said.
In a July 2 letter to the energy commission, CAISO COO Mark Rothleder supported Calpine's request, calling the resource critical even with reduced capabilities. "Without this capacity, the risk of insufficient electric supply in the San Francisco Bay Area increases," the COO said. The project is also essential to the overall reliability of the grid because it is designed to help restart the power system in case of a catastrophic failure, Rothleder added.
But the city of Hayward, where the plant is located, is opposed over safety and air quality concerns, calling instead for a "thorough investigation" before the plant restarts.
"It is not hard to see the potential for fatalities if this situation occurs again," Kelly McAdoo, Hayward's city manager, said in a July 2 letter to the energy commission. The catastrophic explosion at one of Russell City's turbines on May 27 launched shards of metal thousands of feet away, and one 15-pound portion pierced a roof at a nearby center for homeless people, according to McAdoo.
"A catastrophic explosion should not occur at such a young facility," the Hayward official said, pointing to either negligent operations or "defective materials, installation or design." Allowing the project to return to service before a full investigation and mitigation of any safety flaws "is an unjustifiable gamble with the public's safety," McAdoo added.
Calpine is still working on its analysis into the root cause of the explosion, a company spokesperson said in a July 8 email.
The commission will consider whether Calpine can return Russell City to service as a simple-cycle asset at a July 15 meeting.
