Rocky Mountain Power told the Utah Public Service Commission technical conference that its 2025 IRP uses a systemwide run to identify a preferred portfolio and then applies an "integration" step that attributes specific resource additions to the jurisdictions that chose them.

Dan McPhail explained the methodology: "We run the entire system, the civil core system, and we look at all the choices that are made... then the integration process says we only take the decisions that are relevant to that jurisdiction." He said that approach allows the company to identify, for each resource, "which 1 was for Oregon, which 1 was for Washington, and which 1 is for Utah and black and white."

The company said the method is intended to prevent resources driven by another state's policy from being treated as deferrable for Utah customers. Rocky Mountain Power showed that some solar and wind additions in the preferred portfolio are located on the West Side and were selected for Oregon and Washington; those resources are not available to be deferred by Utah qualifying facilities because they were not selected for Utah's jurisdictional needs.

Several participants asked clarifying questions about the draft versus final IRP treatment and the implications for deliverability, cost allocation and whether Utah ratepayers could ultimately carry cost for resources located outside the state. The company responded that the final Utah version constrained east/west sharing more tightly than the draft to avoid allocating out‑of‑state resources to Utah customers if those resources were not deliverable to the customers who would pay for them.