Tucson, Ariz. – UniSource Energy Services electric customers will see immediate relief on their monthly bills under recently approved adjustments that will reduce the average residential bill by about $16 per month.
On Wednesday, the Arizona Corporation Commission (ACC) approved an eight-month credit to return previously collected fuel and power costs to customers. The adjustment to the Purchased Power and Fuel Adjustment Charge (PPFAC) will appear on electric bills beginning May 1 and continue through December 2026, a period that includes the summer months when energy use — and consequently, bills — are typically highest.
This temporary credit will reduce the average bills of a typical residential customer using 884 kilowatt hours by approximately $18.50 per month. Actual savings will vary based on energy use.
That benefit will be partly offset by the impact of an increased Renewable Energy Standard and Tariff (REST) surcharge, which also was approved Wednesday by the ACC. That charge, which was needed to cover increased energy payments to users of rooftop solar power systems, will increase by $2.67 per month for a typical residential customer with average usage.
The new PPFAC credit follows a separate cost-saving action at the end of last year that eliminated a temporary surcharge once it had served its purpose. That earlier decision reduced the typical residential bill by about $21 per month. Together, the two actions amount to nearly $40 a month in savings for the average UniSource electric customer, or about $320 over the remainder of the year.
“These adjustments reflect how our rates are designed to work: passing energy costs through without markup, to reflect prices as they rise or fall,” said Jay Rademacher, Vice President of Finance and Rates. “These are significant fuel and energy cost savings to our electric customers, just in time for summer.”
The PPFAC is a usage-based charge that reflects changes in fuel and energy costs not included in base rates. These costs are passed through without markup or profit. When those costs are lower than expected, the adjustment can become a credit. The surcharge that ended in 2025 had been put in place to recover previously under-collected energy costs. Once those costs were fully recovered, the surcharge was removed, delivering lasting monthly savings to customers.
The higher REST surcharge will fund payments to customers for energy exported from their private solar systems to UniSource’s energy grid, and for energy purchased from large utility-scale renewable resources through long-term purchased power agreements.
Since the previous REST surcharge was approved in UniSource’s 2021-2022 REST plan, the amount being paid to rooftop solar customers has increased from $684,000 per year to over $4 million per year. Rooftop solar installations have more than doubled from 4,702 systems in 2021 to nearly 11,800 systems in 2026.
About UniSource Energy Services
UniSource provides electric service to more than 105,000 customers in Mohave and Santa Cruz counties, including Kingman, Lake Havasu City, Nogales and surrounding communities. It also provides natural gas service to more than 168,000 customers across northern and southern Arizona. For more information about UniSource, visit uesaz.com.
UniSource and its parent company, UNS Energy, are subsidiaries of Fortis, Inc., a leader in the North American regulated electric and gas utility business. For more information visit fortisinc.com.
News Media Contact:
Joseph Barrios
(520) 884-3725
jbarrios@uesaz.com
