Officials from the Public Service Company of New Mexico say electricity was available for the average customer more than 99% of the time last year, however, there were outages, including ones in the East Mountains, Clayton, Santa Fe, Albuquerque and Las Vegas.
The three investor-owned electric utilities in New Mexico presented reliability metrics to the New Mexico Public Regulation Commission on Thursday.
PNM is the largest of the three investor-owned utilities in New Mexico and serves about 550,000 customers. The other two are Southwestern Public Service Company — a subsidiary of Xcel Energy — and El Paso Electric.
The average PNM customer experienced one outage last year and the average outage length was about two hours.
“That’s averaging it out across all of our system,” Omni Warner, vice president of PNM operations and engineering, said.
Some factors that can lead to outages include trees, transmission problems, equipment failures such as cable faults, lightning, vehicles, wildlife such as birds, and unidentified causes. Some of those are related to weather and the major outages that occurred on PNM’s system last year were often caused by weather.
For example, last year lightning struck a substation transformer in Santa Fe. The transformer was damaged and PNM had to shift the load from one substation to another. More than 11,000 customers were impacted by that lightning strike.
In another instance, switchgear failed at the Cochiti substation during a rainstorm. In November, a heavy snowstorm in the Las Vegas area led to a power outage.
“When the weather’s relatively calm, the system holds together really well,” Jeremy Tabet, a distribution engineer with PNM, said.
PNM officials say major event days have been increasing in recent years. Major event days are days when system disruptions are higher than normal and customers are more likely to experience power outages. Last year, there were six major event days. These were connected to weather or wildfires, which are becoming more frequent because of climate change.
As New Mexico hopes for moisture this monsoon season, PNM is preparing for potential infrastructure impacts should that weather occur.
One way that PNM is working to reduce weather-related outages is through vegetation management. In addition to reducing the likelihood of trees causing power outages, vegetation management can reduce the chances that utility infrastructure will spark a wildfire.
The impacts of weather on utility reliability are not unique to PNM. Both EPE and SPS also mentioned weather as a driving cause of outages.
“Weather is the largest impact to our reliability,” Jason Villanueva, EPE’s manager of distribution operations, said.
Another reason why outages may occur is transmission, which can be especially challenging in areas with radial transmission. This happened on PNM’s system in the East Mountains in March 2024 when a crane touched a 46 kilovolt line and caused it to trip. Because the East Mountains area is served by a radial transmission system, there is only one source of electricity running into the service territory. When a line went down, more than 8,000 customers in the East Mountains were left without power.
The public can also cause power outages. The utilities spoke about vehicles crashing into poles and causing outages.
In PNM’s case, one of the outages that impacted thousands of customers last year was caused by a hot air balloon. In October, a hot air balloon knocked out power to more than 12,000 customers in the Albuquerque area when it came into contact with a transmission line.
