The lights went out in San Diego County midafternoon September 8 on one of the hottest days last year. The outage happened after a utility worker in Arizona tripped off an electric transmission line.
Safeguards within the system that should have been able to isolate the problem didn’t kick in, so that initial trip-off cascaded through the system affecting parts of Arizona and California.
In San Diego, schools, businesses and gas stations closed. Traffic lights stopped, creating bottlenecks on roads and freeways. After an eight-month inquiry, federal regulators say a lack of awareness by the utilities running their part of the grid and poor planning were to blame for the blackout.
They also said the outage could have been avoided if more power had been generated locally. But federal regulators declined to say why that didn’t happen. Energy engineer Bill Powers said that omission stands out.
"We know the tactical issues that caused the blackout," Powers said. "But we have not seen from FERC (Federal Energy Regulatory Commission) a big picture view or analysis of whether the way the grid is being operated strategically makes sense under conditions like a heat wave.”
The blackout cost the San Diego region up to $118 million in lost food, productivity and overtime for government employees. Residents and businesses have filed more than 7,000 claims totaling $7 million against San Diego Gas & Electric.
“We are going to deny the claims because the reports have found San Diego Gas & Electric wasn’t responsible for the blackout," SDG&E spokeswoman Stephanie Donovan said.