The Public Regulation Commission voted unanimously on Wednesday to open an official inquiry into why a cooling tower collapsed on June 30 at the coal-fired San Juan Generating Station.
Public Service Company of New Mexico executives told commissioners at the PRC’s weekly public meeting Wednesday that the plant’s insurance provider and independent engineers and contractors are actively investigating the root cause of the collapse, but the reasons it fell remain a mystery for now.
Investigators are carefully examining debris from the tower to help determine what caused the incident, PNM Senior Vice President for Public Policy Ron Darnell told commissioners. But in the meantime, PNM plans to install a temporary cooling tower rented from third-party providers to re-start the unit 1 generator that was connected to the tower.
“We’re preparing for a rented (cooling) unit to be installed later this month,” Darnell told commissioners. “Rental towers are available and we believe we’ll be back online within the next few weeks.”
The tower collapse did force PNM to purchase some electricity on the wholesale power market, and it may need to buy more while unit 1 remains offline, Darnell said. But the plant’s unit 4 generator – the only other operating unit at San Juan after the company permanently shut down units 2 and 3 in 2017 – is back online, following a brief scheduled pause for maintenance that coincided with the accident at unit 1.
Given that unit 4 was already offline when the June 30 incident occurred, the company conducted a separate investigation on that unit to ensure its integrity before bringing it back into operation, Darnell said. And between wholesale power purchases and unit 4 now back online, PNM is able to meet all customer electricity demand, despite the heat wave impacting western states.
“Customers have not been impacted one iota,” Darnell said.
Until now, PNM had avoided any detailed public discussion about the June 30 accident. That generated criticism from commissioners.
“I learned about it in the news nine days after the collapse happened,” Commissioner Cynthia Hall said.
Commissioner Joe Maestas said the PRC received a huge number of calls from citizens concerned about whether there would be enough available electricity in the midst of a heat wave.
“In the absence of information, imaginations run wild,” Maestas said.
PNM Executive Director for Regulatory Policy Mark Fenton said the company routinely informs commissioners about power outages, but not operational issues that don’t affect grid reliability. In addition, the company was concerned that releasing details about the tower collapse might encourage price gouging by wholesale suppliers.
Nevertheless, to ensure a full public accounting of the tower collapse, commissioners voted 5-0 to open an official PRC docket to gather all results from accident investigations and to analyze potential impacts on consumer bills going forward.