A Tucson utility asked more than 400,000 customers for a 14 percent rate hike worth $172 million a year, and the question regulators kept asking about who actually built the grid those customers are paying for

Every summer, a Tucson electric bill has two enemies: the desert heat and the rate on the bottom line. TEP, which serves more than 400,000 customers, is asking the Arizona Corporation Commission, the state’s utility regulator, to increase its rates by 14%. It involves hours of sworn testimony, legal documents, and complicated electricity rate tables. Blue Owl-owned Beale Infrastructure is looking to develop a 290-acre data center campus known as Project Blue in Pima County. The cost-allocation battle buried in utility rate filings has never been more consequential for ordinary households.