Flagstaff, Ariz. • The Navajo Nation has filed to intervene in a rate case for one of Arizona’s largest utilities as it seeks ways to make up for the loss of coal revenue and develop renewable energy projects.

The tribe filed the request this week in the Arizona Public Service Co. case. The utility operates the Four Corners Power Plant and owned a share of the Navajo Generating Station, both on the Navajo reservation.

NGS shut down last year, and APS plans to close the Four Corners plant in 2031. Hundreds of jobs held by Navajos and millions of dollars in revenue to the tribe will be lost.

Navajo President Jonathan Nez has said communities that have long depended on coal should be provided financial resources for their contributions and help transitioning to other sources of energy.

Navajo environmental groups have asked for the same.

The Arizona Corporation Commission is overseeing the APS rate case. It told the utility last year that it should be prepared to propose a transition fund for affected communities.

The Navajo Nation recently filed comments in another rate case for Tucson Electric Power, asking for nearly $62 million to establish a transition fund. The tribe came up with the figure by multiplying the megawatts the utility owned in three coal-fired plants by $100,000.

If the tribe uses the same standard for APS for peak ownership in NGS and Four Corners, the request could top $200 million.

APS has said the utility is participating in economic development forums in the Four Corners region, and would be open about its plans to ease the transition from coal.