Dive Brief:

• Tucson Electric Power (TEP) has moved ahead with three storage projects designed to improve the resiliency of its grid.

• A unit of NextEra Energy Resources has built a 10 MW, 5 MWh lithium nickel-manganese-cobalt energy storage system at a TEP substation, and E.ON Climate & Renewables is building a 10 MW, 5 MWh lithium titanate oxide storage facility and a 2 MW solar array southeast of Tucson.

• TEP is also participating in a two-year research and development project with IHI, Inc. Energy Storage (IHI), which has built a 1 MW lithium ion storage system at TEP’s 5 MW Prairie Fire Solar Array.

Dive Insight:

Last spring the Arizona Corporation Commission approved TEP’s request for two energy storage projects. The utility had originally sought approval for one 10 MW storage facility, but after issuing a request for proposals last June, it found it could deploy two projects for what it had expected to pay for the single project.

TEP says the NextEra Energy storage project helps maintain reliable service for customers during peak demand periods by providing voltage support. The E.ON project is expected online this spring.

TEP will use the third project, with IHI, to study how efficient use of battery energy storage systems can improve electric reliability in Arizona’s hot, dry climate.

IHI will test its ESWare planning and control software and work with TEP to develop efficient control strategies for energy storage systems. TEP says the project will give it the chance to identify the best locations for siting additional storage systems. The IHI system will be charged with energy generated by TEP’s solar array.

TEP says the storage systems avoid the use of more expensive generating resources while expanding renewable resources.

The utility says it plans to add 800 MW of renewable capacity by year end 2030, boosting its total renewable energy portfolio to about 1,200 MW.