April 24, 2025

FERC probes UNS Energy utilities for potential market power abuse

Tucson Electric, UNS Electric, and UniSource face scrutiny over market-based rates after failing market share tests.

Market Power Review: FERC launched an investigation into Tucson Electric Power Co., UNS Electric Inc., and UniSource Energy Development Co. following their failure of wholesale market share tests within the Tucson Electric balancing authority. FERC will determine if the utilities’ market-based rate authority remains justified and establish a refund effective date if necessary, according to an April 21 order. Setting ...

Details:

Filing Date: April 21, 2025

Docket Numbers:

EL25-68

Short Summary:

FERC launched an investigation into Tucson Electric Power Co., UNS Electric Inc., and UniSource Energy Development Co. The investigation follows the companies’ failure of wholesale market share tests within the Tucson Electric balancing authority area during summer and winter periods.

Impact Level:

Categories:

Investigations & Enforcement

Tags: Market Power Investigation, Market-Based Rate Authority

Entities: Fortis Inc., Tucson Electric Power Co., UniSource Energy Services, UNS Energy Corp.

Markets:

Regions: West

States: Arizona

Regulators: FERC

Courts:

Documents:

Market-Based Rate Authority – Order Instituting Investigation