PNM Seeks Approval for $595 Million Transmission Line
Utility files with New Mexico regulators for a 345 kV line and related station work to strengthen its east-to-west transmission system.
Updated on Nov. 2, 2026 in Utilities
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Public Service Company of New Mexico filed a certificate of convenience and necessity on October 30, 2026 with the New Mexico Public Regulation Commission for a new 345 kV transmission line, estimated to cost $595 million. The filing also covers station expansions, a new right of way, and reconstruction of part of an existing 115 kV line.
Why it matters
The project would strengthen PNM's east-to-west transmission system and supports resources identified in its 2029 to 2032 resource portfolio application. It comes as a separate $247 million Rio Puerco to Pajarito to Prosperity line filed in February remains pending before the commission.
The 345 kV line carries an estimated $595 million price tag, and PNM's separate Rio Puerco project adds $247 million, bringing the combined transmission spending to $842 million. The filing does not say how much of either cost would be passed on to ratepayers.
The players
Public Service Company of New Mexico (PNM)
PNM is the state's largest investor-owned electric utility, serving customers across New Mexico and operating as a subsidiary of TXNM Energy.
New Mexico Public Regulation Commission
The state agency that regulates investor-owned utilities in New Mexico and must approve certificates of convenience and necessity for major infrastructure.
The details
The filing seeks approval for a new 345 kV line, station expansions, a new right of way, and reconstruction of part of an existing 115 kV line. TXNM disclosed the request in its third quarter results announcement on October 30.
Timeline
February 25, 2026: PNM applied for the Rio Puerco to Pajarito to Prosperity line.
May 29, 2026: PNM filed its 2029 to 2032 resource portfolio application.
September 1, 2026: PNM filed its 2026 integrated resource plan.
October 1, 2026: PNM filed its distribution system plan.
October 30, 2026: PNM filed the $595 million transmission line certificate request.
Roadmap
The filing is the latest step in a sequence that began with PNM's resource and distribution plans this year and runs through the New Mexico Public Regulation Commission's certificate process. It places PNM's transmission buildout alongside its wind, solar, and battery storage requests under the state's review framework.
Costs for approved transmission projects are typically recovered through utility rates, so the outcome of the commission review could affect what New Mexico customers pay. The filing does not specify how any final cost would be allocated across customer classes.
The takeaway
Large transmission projects move through multi-year regulatory review before construction, so the commission's decisions on this filing and the pending Rio Puerco line will determine the timeline and cost recovery for New Mexico's grid expansion.
Further reading
For related coverage, see Utilities in our business section.
Source note: This article includes information reported by Environment+Energy Leader.
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