Arizona data center boom raises question of who pays for grid

Data centers made up 7% of Arizona Public Service peak demand last summer, according to Greg Bernosky, APS director of large customer strategy. ABC15 reported that the state's largest power provider is already handling record summer power use, and the data center boom is adding a large new source of demand.

How big that share gets is unknown. Asked what portion of APS power data centers would take in 5 to 10 years, Bernosky said he did not know. No forecast was offered in the ABC15 report.

The cost question is already showing up in rate proposals. WCPO reported that an Arizona utility wants to raise residential rates 14% and large-user rates 45% as data centers surge. A Phoenix homeowner, identified only as Reyes, showed a September utility bill of $1,100 for his 4,000-square-foot home. That was $300 more than the same month in 2025. It is one household's data point, not a system-wide measure.

Utilities say the answer is to make large customers cover their own load. APS calls its approach "growth pays for growth." It signs long-term contracts with large users to pay for the infrastructure and energy they request. WCPO reported that other major Arizona utilities, including Salt River Project, say they have similar policies.

Data center operators describe the same arrangement from the buyer's side. Bruno Berti, chief technology officer at NTT Global Data Centers, said NTT paid for all the infrastructure and transmission serving its Mesa facility. He said the community did not bear those costs.

So the pieces on the table are a 7% peak-demand share today, an unanswered question about the next decade, a proposed 45% large-user rate increase alongside a 14% residential one, and contract terms meant to keep new-load costs with the customers requesting the power.

Sources: ABC15 Arizona, WCPO, News 5 Cleveland

This story was produced by Gridline's automated desk from the reporting linked above.