Consultants warn single-substation risk; commission to pursue resiliency grant and phased upgrades

TND Services presented a comprehensive distribution-grid study to the Truth or Consequences City Commission and said the city’s single substation leaves the system vulnerable to extended outages.

“My name is Robert Perea, manager of the planning division at TND services,” Robert Perea said as he introduced the consultant team and the study’s scope. Lead engineer Willie Lopez summarized the analysis and the tradeoffs that informed TND’s recommendations.

The study modeled the city’s electrical system using a GIS inventory and Millsoft load‑flow software to evaluate normal and outage (N‑1) conditions through 2045. TND found that phase imbalance—not inadequate conductor ratings—is the principal driver of under‑voltage violations projected on some feeders beginning in about 2040, and that the substation could exceed the capacity of a single 14 MVA transformer by 2030.

Lopez presented a three‑tiered set of recommendations. Near‑term items include substation maintenance and replacing aging high‑voltage switches and insulators and feeder breakout cables. Midterm steps call for upgrading feeder breakers, relays and metering so staff can balance load between phases and capture fault data. Long‑term planning should assess adding a second substation to create true redundancy.

“The vision would be we would install a new transformer … take the old transformer, have it rebuilt and then create another substation inside the grid. So that’s the dream,” Lopez said.

City manager Whitehead told the commission that the utility’s operating funds appear healthy: “we’re probably in excess of 4 million right now,” and that the city has about $1.5 million in a reserved systemwide fund. Staff described parallel grant pursuits: a federal/state resiliency grant (the recent application window closed before the city’s submission) and a larger $12 million project the commission previously approved for which the city has committed a 10% match.

Gwen Valentino of the South Central Council of Governments, which assists on grant writing, said the TND report will improve future applications but warned that equipment lead times—often 12–18 months—are the chief schedule risk. “We missed that window. It’ll open again next year,” she said of the recently closed resiliency grant.

Commissioners and consultants agreed on a near‑term prioritization: replace or refresh feeder breakout cables and key transmission tie switches, update feeder relays and relays’ coordination settings, and perform targeted substation refresh work while pursuing funding and siting for longer‑term redundancy.

The commission opened the consultants’ findings to public questions and closed the hearing after additional community comments and a brief discussion of next steps. Staff said they will reconvene a public hearing next month on rate study issues and continue to pursue grant funding and engineering work to advance substation planning.