Two Arizona utilities are seeking "fixed-capacity" resources in their latest round of purchases that energy storage systems can provide.
Arizona-based utilities Tucson Electric Power (TEP) and UniSource Energy will seek to procure 450MW of energy from energy storage systems when they each issue an All Sources Request for Proposals (ASRFP).
The solicitations are intended to support the 2020 Integrated Resource Plans (IRPs) issued by the two companies, which need to be submitted to Arizona's utility regulator.
TEP's Wilmot Energy Center comes online in 2021 with 100MW of solar and 30MW of battery storage
TEP's Integrated Resource Plan (IRP) commits the company to reducing carbon emissions by 80 percent by 2035 and providing more than 70 percent of its electricity from renewable sources. The company currently generates around 30% of its electricity from renewable sources after deploying 449MW of wind and solar power in 2021.
The company, which serves nearly 440,000 electricity customers, is seeing a sharp rise in user demand in the areas it serves, hitting record highs in each of the past two years. The company hopes to meet this peak demand with a higher share of low-carbon resources.
At the same time, UniSource Energy aims to use 50% of its renewable energy for retail electricity supply by 2035, while reducing corporate reliance on buying energy from wholesale markets and instead owning and contracting generation resources to supply customers.
UniSource Energy has about 100,000 electricity customers in two Arizona counties and 165,000 natural gas customers in the northern and southern US Southwest.
Both companies are owned by Fortis Group, a Canadian investor-owned gas and electric utility holding company, and announced their purchases last week. Their All Sources Request for Proposals (ASRFP), which launches on April 19, seeks to combine solar and wind power facilities, energy storage and other eligible technologies such as energy efficiency.
Both companies have a deadline of July 1, 2022 for proposals.
UniSource Energy will seek 170MW of renewable energy from solar power facilities, wind power facilities or energy efficiency sources, which may include a demand response program.
The company also needs up to 150MW of fixed capacity, resources that can be called upon when Arizona's electricity demand peaks, providing power for four hours a day during the summer.
The company said energy storage systems could provide this service, allowing utilities to dispatch electricity as needed. It may also include a demand response plan.
TEP said in a press release that it seeks to deploy 250MW of renewable energy and energy efficiency facilities.
TEP Corp., which is preparing to deploy the energy storage system on its own site, said any engineering, procurement and construction (EPC) contractors interested in delivering projects there will organize a tour of the site at TEP Corp. on April 28.
With TEP starting construction of a grid-scale solar-plus-storage system at its service area Wilmot Energy Center in May 2021, the company said it expects to deploy around 1,400MW of storage across its network by 2035.
Both utilities said the procured resources must be available for use from May 1, 2024, and no later than May 1, 2025.
