CPUC hosts workshop as utilities, states and advocates weigh how to add scenario planning to distribution planning

CPUC convened a workshop on April 22 to frame how scenario-based planning will be added to utilities’ distribution planning processes, a move the commission directed in last year’s High DER (distributed energy resources) proceeding.

The workshop, hosted by Tyler Nam, a utilities engineer on the CPUC grid planning team, brought presentations from other state public utility commissions and California investor‑owned utilities, and set a schedule that includes joint utility filings and a June 30 deadline for the Tier 3 advice letter describing each utility’s proposed scenario‑planning implementation.

The commission’s directive and why it matters

Commissioner Hauck opened the virtual component of the workshop, placing the session inside the CPUC’s broader High DER track 1 reform. “This workshop is part of implementing the high DER proceedings track 1 phase 1 decision that was issued last fall,” Hauck said, describing the goal of moving from a single deterministic forecast to a scenario approach that better captures uncertainty around electrification, EV growth, data centers and other drivers.

Why this matters: utilities say a single forecast does not give adequate insight into where and when distribution upgrades will be needed, especially where high‑lead‑time projects such as substations and transformer banks are concerned. Scenario planning is intended to help identify “least‑regrets” investments that reduce the risk of under‑ or over‑building and shorten customer energization timelines.

What the CPUC staff framed

Tyler Nam of CPUC energy division summarized the Commission’s expectations and schedule: utilities must submit a Tier 3 advice letter by June 30 outlining their framework, and the utilities’ scenario proposals must be consistent with, and complementary to, the California Energy Commission’s system‑level IPER demand forecast and other state planning workflows. Nam emphasized transparency and the need for guardrails so that utilities can plan toward a single investment plan informed by multiple scenarios.

What other states reported

Hannah Terwilliger, analyst coordinator with the Minnesota Public Utilities Commission, described Minnesota’s multi‑year Integrated Distribution Plan (IDP) program and how Minnesota uses scenario analysis to inform proactive upgrades. Terwilliger said Xcel Energy—Minnesota’s largest utility—faces substantial distribution congestion: it…