Ariz. utility plans record solar battery as coal plant closes

Source: By Edward Klump, E&E News reporter • Posted: Monday, November 18, 2019

The Salt River Project, an Arizona power provider that has a stake in the closing of coal-fueled Navajo Generating Station, has committed to two new solar and energy storage developments — including one projected to be the biggest solar-charged battery project in the state.

The Sonoran Energy Center will have roughly 250 megawatts of solar capacity to charge a 1,000-megawatt-hour energy storage system, according to SRP. The Storey Energy Center will involve about 88 MW of solar capacity associated with a 264-MWh storage system, SRP said.

“The commitment by Salt River Project to invest in a 1,000 MWh battery storage system will be one of the largest single battery projects in the world, so this is an exciting development,” Kelly Speakes-Backman, CEO of the Energy Storage Association, said in a statement. “The project highlights just how far energy storage has come in a short period of time.”

SRP, a public power utility, is the biggest electricity provider for the Greater Phoenix area. It serves over 1 million customers. The solar and storage announcement last week came as the Navajo Generating Station has been winding down its last few days as a power producer. While SRP expects to use generation fueled by natural gas to help fill much of the coal plant’s void, solar and storage are elements that will be in the future energy mix. SRP’s generation sources include everything from renewables to other coal assets to nuclear, according to the utility’s website.

The new solar plants are slated to be online by June 2023, and they are to be owned and operated by units of NextEra Energy Resources LLC. SRP will climb to more than 60% of a goal of adding 1,000 MW of new utility-scale solar energy to its system by the end of fiscal 2025, according to Mike Hummel, SRP’s CEO and general manager.

“These integrated solar and storage plants will allow SRP to meet its summer peak demand, reduce carbon emissions, and provide clean energy to our customers while optimizing energy output using state-of-the-art battery technology,” Hummel said in a statement.

Last week’s announcement was the latest attention for batteries in Arizona. In February, Arizona Public Service Co. revealed a plan to add 850 MW of battery storage and at least 100 MW of new solar. But it has delayed some of its battery expansion plans in the wake of a fire at a storage site in the state (Energywire, Aug. 9). An investigation into that incident continues.

Patty Garcia-Likens, an SRP spokeswoman, said via email last week that batteries have been operating reliably and safely at utilities across the country. Batteries that experienced fires and failures make up a small segment of operating batteries, she added.

“With these two new projects not coming online until 2023, SRP and NextEra will have ample time to incorporate any lessons learned and any enhancements made in battery management systems and evolving chemistries that will only help to make battery energy storage systems even more reliable resources for the grid,” Garcia-Likens said.

SRP’s investment in the Sonoran and Storey centers comes, she said, through power purchase agreements whose terms are confidential. SRP isn’t planning to adjust customer bills because of them, she said.

The new capacity was picked as a “result of an all-source [request for proposals] process to meet SRP’s growing customer load and represents a competitively priced energy supply source for our customers,” Garcia-Likens said.

For SRP, the new projects will aid a 2035 goal to lower generation carbon emissions per megawatt-hour by over 60%, and by 90% in 2050, compared with 2005 levels. The new plants will produce enough solar energy to power about 100,000 homes, according to SRP. The idea is to make surplus energy available from batteries when demand is high.

Matt Handel, vice president of development for NextEra Energy Resources, said in a statement that the projects will “provide a significant economic boost for their local communities and for Arizona, including good jobs and millions of dollars in additional tax revenue.”

The addition of a major battery project also boosts hopes for hitting 35 gigawatts of new energy storage systems in the United States by 2025. More than 1 GW is deployed in the United States, based on data from the Energy Storage Association.

“According to the most recent estimates, we’re on pace to see approximately 480 MWh of storage deployed for 2019, so a project of this magnitude is a noteworthy milestone as we continue working toward our goal of reaching 35 GW of storage by 2025,” Speakes-Backman said.

Still, she said, energy storage “has a long way to go for making the grid more resilient, efficient, sustainable and affordable.” Speakes-Backman said projects like these could be the norm if Congress acted to expand the investment tax credit to include all stand-alone storage.

She also said the industry has made safety a top priority, noting her association’s formation of the Corporate Responsibility Initiative to help showcase best practices.

“It’s important for regulators, utilities and developers to work together to ensure all risks are addressed and mitigated as a part of standard operations,” Speakes-Backman said. “This includes all assets — generation, wires, pipeline and energy storage.”