Salt River Project is experiencing “explosive growth” in its service territory, particularly in Maricopa County, Arizona, and is exploring non-inverter based long-duration energy storage to meet the rising demand.
On Tuesday, the utility announced a request for information for non-lithium-ion storage resources to come online between 2027 and 2028.
“We’re seeking information on emerging storage technologies to consider how these could support SRP’s sustainable power system of the future,” Chico Hunter, manager of innovation and development, said in a statement. “We’re proud of SRP’s many storage projects coming online, and with the significant growth in our service territory, it is important we continue to pilot new resources.”
In August, SRP tapped Germany’s CMBlu to deploy a 5 MW, 10-hour storage project. Now, the utility is asking developers to submit information about potential demonstration projects from 5 MW to 50 MW, capable of delivering energy for 8-12 hours.
“Eligible storage technologies must be non-inverter based or have mechanical inertia,” according to the RFI.
SRP’s most recent Integrated System Plan shows the utility could need to triple its power resource capacity within the next decade. Maricopa County is one of the fastest growing counties in the nation, and the new demand combined with the utility’s decarbonization goals creates a resource challenge.
SRP is a not-for-profit public power utility serving 1.1 million customers. The utility has a goal to reduce its carbon intensity by 65% by 2035 and by 90% by 2050, relative to 2005 levels, along with plans to significantly increase solar and battery storage capacity. But the RFI also notes it is “interested in alternatives to traditional battery storage in terms of grid support and safety.”
The reliability of inverter-based resources has come under scrutiny after a series of battery and solar failures. “Poor commissioning practices” are contributing to “unreliable performance,” according to a report published Monday by the North American Electric Reliability Corp. and the Western Electricity Coordinating Council.
SRP said it will consider technologies that can be paired with existing gas or steam turbines, but “for the purposes of the demonstration project, it is assumed the respondent would provide an entire new system including the turbine.”
The utility also said it is primarily interested in power purchase agreement options for a request for proposals that may result from the RFI, but for now “will only require a capital cost estimate, as well as operating and maintenance costs.”
SRP has scheduled an Oct. 19 webinar to discuss the RFI, and responses are due Dec. 22.