US utility testing 5 MW, 10-hour organic solid flow battery


Salt River Project (SRP), a not-for-profit energy company serving more than 1.1 million people in Arizona, has announced plans with German battery manufacturer CMBlu for a pilot project to deploy long-duration energy storage (LDES).

The 5 MW, 10-hour-duration Desert Blume project will use CMBlu’s non-lithium technology. CMBlue will build, own and operate the batteries on behalf of SRP at its Copper Crossing Energy and Research Center in Florence, Arizona.

CMBlu said its Organic SolidFlow battery technology is based on fully recyclable organic materials. It uses aqueous electrolyte solutions that are non-flammable. The company said the batteries are characterized by free scalability between power and capacity because the system separates the electrolyte from the actual energy converter, and self-discharge is avoided. Furthermore, by replacing individual components, original performance can be restored.

CMBlu expects its battery system to cost-effectively store and deliver energy for two to three times longer per cycle than traditional lithium-ion technology, which typically targets a four-hour duration.

While the battery installations are a pilot, SRP is depended on to provide water to about half of the valley’s residents, delivering more than 244 billion gallons of water each year, and it manages a 13,000-square-mile watershed that includes an extensive system of reservoirs, wells, canals and irrigation laterals. The battery project is designed to store energy for SRP’s customers during daytime periods, largely from solar generation, and return that energy to the grid throughout the night. It will store enough energy to power about 1,125 average homes for 10 hours.

In 2022, a fire broke out at the Salt River Project when a lithium-ion battery began smoldering. Area businesses were evacuated out of an abundance of caution due to the potential hazards caused by off-gassing. As an alternative to lithium-ion, the project is implementing the Organic SolidFlow batteries in the pilot project. This is the first U.S. utility implementation of CMBlu’s batteries at this scale.

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SRP selected CMBlu after issuing a request for long-duration storage project proposals from emerging energy storage companies. The Electric Power Research Institute (EPRI) will monitor the pilot project and help validate the performance of the technology in Arizona’s hot and dry climate.

This pilot is part of the third phase of development at SRP’s Copper Crossing Energy and Research Center. The first phase will add two flexible natural gas turbines with a total output of less than 100 MW, and the second phase will add a utility-scale solar generation facility capable of generating up to 55 MW of solar energy. Construction of the third phase is slated to begin in early 2025, and the pilot is expected to be operational in December 2025.

CMBlu’s technology will also be deployed in other pilot projects including one in Burgenland Energie in Austria, and another pilot in Milwaukee, Wisc. with WEC Energy.

CMBlu was founded in Germany in 2014 by biotech entrepreneur Peter Geigle and a group of German energy and automotive executives. Since passage of the Inflation Reduction Act, CMBlu has entered the US market.

“Compared to Germany and the rest of Europe, the US is clearly marching ahead in the development and application of large-scale storage solutions,” said Peter Geigle, founder and CEO. He added that once the company’s products gain acceptance, it will remain “fully committed to a US manufacturing presence.”

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