A Public Utilities Commission technical conference on proceeding 21-0141E on near-term procurement highlighted transmission constraints that may limit the ability to deliver roughly 5 gigawatts of new generation by 2029.

Commissioner (questioner) Mr. Detsky pressed company witnesses about an open-access transmission tariff and modeling in a DC transfer-limit study, saying the study shows "you essentially have to back down a lot of the system as it exists today to get power to flow." He warned that attempting to interconnect and deliver 5 GW next year without mitigations would be difficult.

Company witnesses acknowledged the limits. "Everything that we have seen and produced has shown that, to add incremental generation, we're gonna need to have incremental transmission," said Mr. Landrum, citing the JTS phase 1 transmission study and ongoing CCPG work. At one point he referenced an order-of-magnitude figure: "due to $2,500,000,000 of incremental investment," tied to studies to turn analysis into project-level mitigations.

Why it matters: the study uses linear (DC) power-flow methods—rather than an AC model—and scales down existing generation to balance cases that include several gigawatts of new bids. That modeling approach, witnesses said, can expose systemwide flow constraints (not just local problems) and signals that substantial network upgrades will be needed to accommodate accelerated interconnection timelines.

The commissioners and company witnesses stressed geographic nuance. Mr. Detsky noted the modeling emphasized flows around the Denver metro area and warned that the study does not capture deliverability needs in other regions such as the San Luis Valley. Company staff said some San Luis Valley mitigations were included in the $2.5 billion estimate, and that CCPG modeling will be updated to reflect the actual set of bids in the NTP portfolio to refine needed projects and schedules.

Direct costs and ratepayer impact were flagged. Mr. Detsky argued "all these costs are gonna end up being paid for by ratepayers," and company witnesses said some TPIF/network-upgrade costs are initially funded by bidders or by the utility and then accounted for in customer-facing pricing analyses.

What comes next: the utility and CCPG participants will run more detailed portfolio-based modeling to translate the high-level transfer-limit results into concrete mitigation projects. Witnesses said those efforts should produce more refined mitigation lists and budgetary estimates that can be considered through CPCN and related regulatory processes.

Provenance: This article summarizes public questioning and company responses beginning with the return to public session for Mr. Detsky's questioning and the DC transfer-limit discussion (topic start: SEG 141; topic finish: SEG 476).