Tucson, Ariz. – UniSource Energy Services and Tucson Electric Power (TEP) are seeking new generation facilities, energy storage systems and other resources such as energy efficiency through a joint all-source request for proposals (ASRFP) that seeks submissions by March 8, 2024.
The joint ASRFP, issued in December 2023, targets resources to support the companies’ 2023 integrated resource plans (IRPs), which describe how each company plans to meet customers’ increasing energy needs over the next 15 years while maintaining affordable service.
“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 Chief Executive Officer. “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.”
In the ASRFP, TEP and UniSource are seeking bids for all resource types, including:
- Up to 625 megawatts (MW) of renewable and energy efficiency resources. This could include new wind and solar generating systems and new energy efficiency initiatives, including demand response programs that reduce usage during periods of high energy demand.
- Up to 825 MW of “firm capacity” resources that can be called on at any time, including energy storage systems designed to provide at least four hours of continuous energy every day during the summer for the companies to dispatch as needed. This also could include demand response programs that provide incentives to customers who curtail energy usage at specific times of the day and year when usage is typically highest.
The companies will review proposals before summer and anticipate selecting successful proposals this fall. Both companies are seeking resources that can commence service as soon as May 1, 2026 but no later than May 1, 2027. Projects with combined technologies are eligible for consideration.
TEP’s 2023 IRP describes how the company will accelerate its clean energy expansion while reducing carbon dioxide (CO2) emissions and other environmental impacts. TEP expects to add 2,240 megawatts (MW) of wind and solar generation and 1,330 MW of energy storage by 2038, as well as 400 MW of natural gas turbines to help offset coal plant retirements and support higher use of variable wind and solar energy. This balance was determined to be the most cost-effective way to maintain reliability while achieving an 80 percent reduction in CO2 emissions by 2035, a goal set in TEP’s 2020 IRP.
UniSource’s 2023 IRP outlines the company’s plans to more than double its electric energy resources amid increasing resource constraints on the regional electric grid. The plan calls for the addition of 350 megawatts (MW) of solar and wind resources, 200 MW of natural gas turbines and 225 MW of energy storage systems by 2038. UniSource currently has about 300 MW of generating capacity.
The ASRFP process is being supported with evaluation and independent monitoring services provided by Sargent & Lundy. More information, including bidder registration and ASRFP material, is available at uns2024asrfp.com.
In October 2023, TEP announced plans for Roadrunner Reserve, a 200-MW, 800-megawatt-hour battery energy storage system. The project was selected as a result of TEP’s April 2022 ASRFP. TEP will own and operate the system, which will be designed and built by Scottsdale-based DEPCOM Power, Inc. The system, announced in October, is expected to be ready for use in 2025. Other projects submitted during the April 2022 solicitation remain under consideration.
About UniSource and TEP
UniSource provides electric service to more than 101,000 customers in Mohave and Santa Cruz Counties. It also provides natural gas service to more than 167,000 customers in Northern and Southern Arizona. For more information, visit uesaz.com.
TEP provides safe, reliable electric service to more than 445,000 customers in Southern Arizona. For more information, visit tep.com.
TEP, UniSource and their parent company, UNS Energy, are subsidiaries of Fortis Inc. (TSX/NYSE: FTS), which owns utilities that serve more than 3 million customers across Canada and in the United States and the Caribbean. To learn more, visit fortisinc.com.
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