July 28, 2023

Utilities say advanced preparation has helped keep lights on during heat wave

So far, New Mexico has fared well in terms of grid reliability during record-breaking summer heat. 

Investor-owned utilities say outages this summer generally have not been related to heat. Storms have knocked out power and other incidents, such as vehicles crashing into infrastructure, have caused outages. Southwestern Public Service Company, a subsidiary of Xcel Energy that serves Texas and New Mexico, saw most of its outages come from factors like high winds, flooding and tornadoes, according to spokesman Wes Reeves.

But that doesn’t mean the utilities have not had to prepare for the heat, which has shattered records across the country, including throughout New Mexico.

When heat increases, demand for electricity does as well. This is because people run air conditioning and stay indoors during the day.

Heat can also impact the infrastructure, including limiting the amount of electricity power lines can carry and increasing the likelihood that transformers will fail.

Some heat-related outages have occurred in the Texas service territory for the investor-owned utilities. That includes a power outage in El Paso this week and a power outage in late June in Amarillo.

El Paso Electric serves parts of southern New Mexico, including Las Cruces and Alamogordo.

Following the El Paso outage, El Paso Electric, in a tweet, emphasized the importance of being “energy wise” during the hours of 4 p.m. to 8 p.m. when demand for electricity peaks. El Paso Electric also has a guide for energy wise practices.

At the same time, the increased demand for electricity has been noticeable.

“This summer has been a record summer for temperatures,” Eric Chavez, a spokesperson for the Public Service Company of New Mexico, told NM Political Report in an email. “With this comes increased usage in energy. On July 17 and again on July 18, PNM recorded an unofficial historical peak load of 2,131 (megawatts) compared to a previous high recorded in 2022 of 2071 MW.”

Chavez said the utility does not anticipate having heat-related rolling outages this summer. 

“We continue to monitor the weather and our load forecast so we can continue to provide reliable power during these warm summer months and to respond as quickly as possible to any localized outages we experience,” he said.

PNM is not alone in experiencing increased demands.

Reeves said that the year-to-date electricity demand is roughly the same as it was in 2022, but the demand this week in particular is higher. He said there is about a 4 percent increase in demand for electricity this week compared to the same time last year due to the high temperatures. 

Utilities take steps throughout the year to prepare for the summer heat, according to El Paso Electric. Those steps include maintenance and inspection of transmission lines, purchasing additional equipment for items that are commonly impacted by heat, increasing the number of crews available during peak hours to deal with potential outages, coordinating seasonal readiness at power plants and evaluating operating procedures. 

Generation assets across the western grid have performed well this summer, Chavez said.

Many western utilities participate in an electrical sharing agreement that allows utilities to send excess power to areas that may be experiencing shortages. 

The generation assets performing well this summer has allowed for additional availability of electricity across western utility markets, Chavez said.

Reeves also noted that generation assets have performed well this summer.

“Our regional generating fleet has performed well this summer and our overall supply of power has been more than enough to meet customer needs,” he said. “To date, we have not had any issues that led to public appeals to conserve electricity.”

But having the generation assets such as power plants and solar arrays ready for the summer means advanced planning.

Chavez said PNM takes “extensive efforts prior to the summer months to ensure its resources are ready to perform at a high level during the most critical periods of the year.”

He said providing reliable service is not easy and requires extreme dedication from the employees.

“We are extremely proud of the dedication our employees have to serving our customers,” Chavez said.

Climate change and the increase in electrification, including electric vehicles, brings more challenges.

“One of the trends we have observed in recent years is the increase in the length of time and the wider geographical footprint of the high heat events occurring,” Chavez said. “We obviously see both of those continuing for the summer of 2023. This means that PNM must ensure we continue to focus on and develop resources that can provide extended duration service to our customers during these critical time periods.”

PNM and other utilities have increased their planning reserve margin targets—or the amount of extra power available to meet increased demands—to account for the more frequent extreme weather events as well as the variability in renewable energy production, Chavez said.  

The Southwest Power Pool has increased its reserve margin from 12 percent to 15 percent, meaning that utilities should have 15 percent more capacity than needed to meet typical energy demands on their systems, according to information SPS filed with state regulators this week.

“PNM plans to continue to evaluate and make additional adjustments as necessary,” Chavez said. “In addition…PNM continues to look at increasing resources that provide reliable service during long duration heat events, including longer duration storage resources. PNM has also initiated additional studies, including cooperation with our national labs, that investigate the impacts of climate change on our longer-range planning needs.”

SPS and Xcel Energy are paying close attention to portions of its service area where lines and substations are nearing capacity and, Reeves said, the utility has “invested in new and upgraded substations and power lines to alleviate the strain.”

“These upgrades not only prepare the system for high-demand periods but also build in capacity for future growth,” he said.

At the same time, SPS and other utilities across the country are facing aging generation assets such as power plants.

Reeves said SPS is retiring some of its oldest power plant units and has announced plans to update at least two of the sites with solar arrays and battery storage. That includes two separate solar arrays—a 72-megawatt facility as well as a 196-megawatt facility—at the Cunningham Generating Station near Hobbs as well as 36-megawatts of battery storage at the power plant.

At the same time, fossil fuels are not entirely being removed from the grid.

On Wednesday, SPS submitted plans to the New Mexico Public Regulation Commission and the Public Utility Commission of Texas to extend the life of the natural gas Cunningham Generating Station Unit Two from 2025 to 2027 and the Maddox Unit Two from 2025 to 2028. The Maddox Station is also a natural gas power plant in the Hobbs area.