Real-time decisions: A peek inside PNM’s operations

A flick of a switch or the press of a power button in one household to turn on air conditioning affects nearly the entire state’s power system.

Three people sitting in a quiet room surrounded by computer screens, with a massive monitor with a color-coded map full of data spanning across an entire wall before them, are responsible for making sure the state’s electric grid is operating safely and effectively so that one household can ultimately get AC.

They control a significant portion of the electric grid for basically the entire state.

These system operators work in the generation and transmission center for the Public Service Company of New Mexico and have to make split-second decisions every day and night to ensure the grid stays working.

It’s a unique job amid a state and federal renewable energy transition and is becoming increasingly unpredictable as New Mexico starts relying more on the sun and wind for energy generation rather than fossil fuels like coal.

With the press of a button, the system operators isolate power in different parts of the state to address imminent issues, like overloading power lines.

Challenges of the energy transition

These real-time energy decisions are getting more complex with time.

Kelsey Martinez is the director of regional markets and transmission strategy at PNM. She said the clean energy transition majorly affects how the utility makes split-second power decisions.

In the past, utilities would trade energy every hour. Martinez said that worked well because energy was so predictable with fossil fuels.

It doesn’t work as well anymore because of how unpredictable wind and solar energy generation is; a utility can’t control the amount of sun and wind energy coming in.

“Our job has become a lot bigger because (of) the difference between the plan and what’s happening in real time,” Martinez said.

The generation is also coming in from different places, she said. As opposed to one 800-megawatt coal plant, she said, there are lots of little 50-megawatt solar farms.

“It’s a completely different ballgame to balance generation to load and to control voltages, and to keep track of all of this from a financial perspective,” she said.

PNM spokesperson Kelly-Renae Huber said the company is on track to be 75% carbon-free by 2027. New Mexico requires the utility to be completely emissions-free by 2045.

“It’s ambitious for the region,” Martinez said.

One strategy that Martinez said could help in the transition is a regional power system.

Currently, individual electric utilities manage the balance of generation, transmission and demand, creating what Martinez described as small bubbles of sovereignty around the West. There are 38 entities, called “balancing authorities,” across the western power system, according to Western Clean Energy Advocates.

A regional transmission organization would dial that down to just two or three ultimate authorities. Martinez said it would be more effective that way, with a larger, federal entity overseeing power balance in the West, because the entire western grid’s power system affects every state on this side of the U.S.

For example, if a power line gets overloaded in California, an influx of energy could get sent to New Mexico instead, and vice versa. Martinez explained that power takes the path of least resistance, so if a line in a city like San Diego has problems, the power automatically reroutes to other western states, like New Mexico, Utah or Arizona.

“I think that’s just something that most people don’t realize, is that we’re really dependent on the region, the entire western United States,” Martinez said.

The New Mexico Public Regulation Commission, which oversees utilities in New Mexico, is in support of a regional market, Martinez said, but other states aren’t so eager to give up their utility autonomy.

“We’re very supportive of it,” Martinez said. “It’s moving too slow for us, but at least it’s moving.”

PNM joined the Western Energy Imbalance Market in 2021, which allows the company to buy and sell power with nearly two dozen other participants in real-time when customers are using electricity. It’s a strategy that improves balancing supply and demand, according to the energy market, and PNM has reported $44.4 million in customer savings because of it.

“It brings direct customer savings,” Huber said.

By the end of 2026, Martinez said, PNM wants to make a decision on joining a day-ahead market in addition to the real-time market the Western Energy Imbalance Market provides.

One positive with the clean energy transition is that it allows PNM an opportunity to conduct necessary updates to an old power grid.

“That was going to be a big challenge anyway,” Martinez said. “It’s just kind of all hitting at the same time.”

She said PNM is able to build out for the future all at once, taking advantage of improvements “that are going to support future technology and future electrification.”

Internal operations

PNM has 20 system operators working at the real-time generation and transmission center total. Distribution is overseen at another facility.

Martinez said it takes unique skills to act as a system operator at the utility’s real-time generation and transmission center. One would assume it’s all engineers, she said, but the profession requires quick decision-making, which not all engineers have.

“It’s this weird mix of very technical people that are able to act and don’t get paralyzed by data overload or just fear of taking action that’s going to have some really big effect,” she said.

Aidan Gallegos, PNM’s manager of system operations, said it takes three years for an operator to become fully trained. Huber added that the personnel need to continually take trainings after that, too.

“It takes a lot of work to be able to run one of these desks and manage this frequency and continual education,” Huber said.

PNM holds emergency drills at the center regularly, Martinez said.

For example, she said the facility has to simulate a black start annually — when utilities restore power to the grid without the help of the external transmission network in order to recover from a shutdown.

Martinez said Texas was close to a black start when Storm Uri hit in 2021, a major winter and ice storm that significantly affected Texas; New Mexico ratepayers also had to pay a surcharge for electricity because of the storm. Martinez said Texas had to implement actions to avoid a complete collapse of its system.

The state would’ve also been better off if its power was connected to the western or eastern power grid, she said. Texas’ power grid is independent of the rest of the U.S.

PNM also has safety precautions to present physical harm to linemen. The company has a three-part communication system to ensure power grids are being turned on or off at the correct times when linemen are getting work done.

“It’s just safeguarding and checking to make sure that we have basically electrically isolated points, so that the linemen can guarantee they’re not going to be energized while they’re working on it,” Martinez said. “And it’s a huge deal.”

And in a time where cyberattacks are becoming more and more common, PNM also has digital safeguards. The computers that control the grid are separate from the internet, so hackers couldn’t access it.

“We’ve got a lot of safeguards,” Martinez said.