US utilities Tucson Electric Power (TEP) and UniSource Energy have launched a joint all-source request for proposals (ASRFP) for new power generation facilities and energy storage systems (ESS), for up to 625MW of renewable power capacity and up to 825MW of “firm capacity”.
The utilities are both based in the US state of Arizona, and their request will be open until 8 March this year, with proposed projects required to begin operation between 1 May 2026 and 1 May 2027. The renewable capacity component of the request is open to new solar and wind projects, alongside “new energy efficiency initiatives, including demand response programs,” according to the companies.
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The storage component is looking for 4-hour storage systems, designed for use in the summer to provide electricity during months of high demand. Last summer, Arizona posted a record electricity demand of 8.1GW amid a heatwave on 15 July, and the state’s utilities are keen to reinforce its energy grid to ensure its citizens have access to electricity this summer.
“We’re looking for opportunities to add reliable, cost-effective resources to satisfy the growing energy needs in communities we serve,” said Susan Gray, president and CEO of Fortis, a Canadian-headquartered firm that owns the UNS Energy Corporation, the parent company of both Arizona utilities.
“As in our previous ASRFP, we’re particularly interested in resources that can provide service during the late afternoon and early evening hours of summer, when our customers typically use the most energy,” added Gray.
The two utilities collectively serve more than 500,000 customers in Arizona and have both announced plans to expand their renewable power installations in the coming years. TEP aims to add 2.2GW of new solar and wind capacity by 2038, alongside 1.3GW of energy storage, while UniSource is looking to add 350MW of new solar and wind by the same year.
Projects such as these could be of benefit to the sizable Arizona solar sector, which included 6.7GW of installed capacity as of the third quarter of 2023, according to the Solar Energy Industries Association (SEIA). This is the fifth-most capacity among the 50 states, and the association expects Arizona to add the fifth-most new capacity over the next five years.
Arizona has benefitted from considerable investment in solar technology and manufacturing in recent months. Last year, Terabase installed 17MW of solar capacity at an Arizona solar project using automated machinery, and last week, Meyer Burger received its first shipments of equipment at its latest manufacturing facility, a 2GW module assembly plant in Goodyear.
