UniSource Energy Services to Issue New All-Source Request for Proposals

TUCSON, Ariz.--(BUSINESS WIRE)--UniSource Energy Services is seeking new generation facilities, energy storage systems and other resources such as demand response and load management through an all-source request for proposals (ASRFP) that will be open for submissions through April 11, 2025.

The ASRFP will target resources to support UniSource’s 2023 Integrated Resource Plan (IRP), which calls for expanding the company’s generation capacity to satisfy growing summer and winter energy needs, and reducing the company’s dependence on wholesale energy market purchases.

UniSource is seeking competitive proposals to add up to 200 megawatts (MW) of firm summer and winter capacity. Supply-side resources, such as natural gas generation or energy storage systems, must be able to provide capacity and energy coincident with the company’s energy needs and must be able to achieve their summer-rated capacity each day of the summer.

Demand-side resources such as demand response and load management may provide load reductions for less than four continuous hours but must be responsive enough to provide benefits during times of need.

UniSource will review proposals before summer and anticipates selecting successful proposals this fall. Although dispatchable capacity and energy resources are preferred to be in service by May 1, 2028, the company will accept proposals for resources with in-service dates as late as May 1, 2029.

UniSource’s 2023 IRP outlines the company’s plans to more than double its electric energy resources amid increasing customer demand and 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.

Sargent & Lundy will provide evaluation and independent monitoring services to support UniSource’s ASRFP process. More information, including bidder registration and ASRFP materials, are available at www.uns2025asrfp.com.

UniSource provides electric service to more than 104,000 customers in Mohave and Santa Cruz counties. It also provides natural gas service to nearly 170,000 customers in 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 industry. For more information visit fortisinc.com.