Officials from the Public Service Company of New Mexico said Monday that the previous night’s power outage was the worst in more than 15 years, and was caused when a substation at Ouray and Unser NW was hit by a bolt of lightning so powerful that it bypassed lightning rods and other protection equipment.
The lightning severed cables carrying electricity, disintegrated porcelain insulators and melted or vaporized conductors and other components at the substation, said Aubrey Johnson, PNM’s vice president for operations.
The voltage surge tripped circuit breakers up and down the power grid, disrupting service from Los Lunas to Santa Fe. It affected 81 substations throughout the system and 128,647 customers – a lower total than PNM first estimated. There were also two local power generating stations that were briefly tripped offline.
PNM officials were unable to say which areas specifically in that wide swath had their service interrupted, but pockets within heavily affected areas experienced no disruption of power.
“All substations are designed to sustain some level of lightning strikes,” Johnson said. The Sunday night event, however, was more than the substation could handle. The good news, he said, is that the system performed as it was designed to do. It shut itself down to prevent the voltage from surging through the system, minimizing damage to the power grid itself and to electrical devices used by customers along the way.
Johnson said he was unaware of any damage caused by a power surge at businesses or residences.
The lightning hit the substation about 7 p.m. Within the first hour, about half of the affected area had power restored; the remainder of the affected area was restored over the next two hours, Johnson said.
Other customers may have been without power for longer, but those outages were caused by separate events, he added.
Services and patients at local hospitals were unaffected. PNM spokeswoman Karen Scott said all hospitals have standby electrical generators that automatically start when electrical power is interrupted.
“Backup power went on immediately at our three area hospitals – Presbyterian Hospital, Presbyterian Kaseman Hospital and Presbyterian Rust Medical Center,” said Sandra Podley, a vice president and administrator at Presbyterian Healthcare Services. “Normal power was restored across the metro area in phases. As a result, we remained on backup power for about an hour at Presbyterian Hospital, 30 minutes at Presbyterian Kaseman Hospital, and one hour and 45 minutes at Presbyterian Rust Medical Center.”
Likewise, the Albuquerque Police Department was largely unaffected because of a backup generator at the 911 dispatch center, said department spokeswoman Celina Espinoza. That includes the onboard data received by officers in the field, which also goes through the dispatch center.
There were, however, a “few minor car crashes” that occurred when motorists entered intersections where traffic lights were out, she said.
Santa Fe police reported that a fatal traffic accident occurred when a motorcyclist stopped at an intersection where a traffic light was out and was then struck from behind by a car. Alcohol was not a factor, police said.
Sunday’s outage was the worst since 2000, when a brush fire caused interruption to about 1 million people statewide, although not all of them were PNM customers, Johnson said.