Ambri has advanced cooperation with Xcel Energy in a long-term energy storage project.
Ambri, a Massachusetts Institute of Technology (MIT) spinoff, has developed a liquid metal battery for long-term energy storage solutions. Designed for daily cycling in harsh environments, the expected battery life is more than 20 years without fading, Ambri said. Although the battery is now in use in data centers, the reported test at Xcel Energy is the first reported installation by the utility.
Xcel Energy and Ambri are planning a year-long test of the 300 kWh system at the Solar Technology Acceleration Center (SolarTAC) in Aurora, Colorado. SolarTAC is owned and operated by Gray Snow Management Solutions, a tribally owned economic development company. The test center was founded in 2009 by the original founding member companies Xcel Energy, SunEdison and Abengoa Solar, with the task of testing renewable energy technologies in a real, grid-connected environment.
Installation of the Xcel system is expected to begin in early 2024, with the system fully operational later this year. In the pilot, different usage methods are tested, such as solar and wind power integration, capacity management, arbitration and ancillary services. It uses SolarTAC’s GridNXT Microgrid Platform to integrate multiple generation sources such as solar and wind, as well as inverters, load banks and three-phase distribution connections and communications.
Xcel Energy became the first utility in the United States to set a long-term goal of providing its customers with carbon-free electricity. The company’s goal is to be net zero in terms of electricity, heat and transport by 2050.
“Xcel Energy is a forward-thinking and ambitious utility, and their enthusiasm for testing our system underscores the enormous potential of liquid metal batteries,” said Adam Briggs, Ambri’s Chief Commercial Officer. “Xcel Energy clearly understands the significant value that can be achieved by integrating innovative storage technologies into its renewable product portfolio.”
Xcel Energy plans to develop a follow-on Memorandum of Understanding (MOU) for larger capacity long-term energy storage projects to follow the upcoming 300 kWh system at SolarTAC.
“Xcel Energy has always been at the forefront of energy companies’ transition to carbon-free electricity,” said Justin Tomljanovic, vice president of corporate development at Xcel Energy. “This demonstration project with Ambri gives us the opportunity to explore technology that could help us continue to reliably deliver the energy our customers depend on throughout the clean energy transition.”
Ambri’s batteries, manufactured in Milford, Massachusetts, feature a liquid calcium oxide anode, a molten salt electrolyte, and a cathode composed of solid antimony particles, allowing for the use of inexpensive materials and a small number of steps in the cell assembly process.
The company said the active materials in its cells are reversibly doped and de-doped during charging and discharging. The electrolyte is thermodynamically stable with the electrodes, avoiding side reactions such as film formation that can lead to performance degradation. The negative electrode is completely consumed when it is discharged, and is regenerated with each cycle, resulting in what the company said is a “highly repeatable process with no memory effect.”