Xcel Energy eyes Ambri antimony batteries for clean energy storage

Xcel Energy, a utility company that generates enough electricity to power roughly 23 million homes across eight states, has selected the liquid-metal batteries produced by Amri Inc. as a potential long-term clean energy storage solution.

"Partnering with a progressive and innovative utility such as Xcel Energy is an exciting opportunity for Ambri as their clean energy vision is directly aligned with our mission to leave the planet a better place for future generations," said Adam Briggs, chief commercial officer at Ambri.

In 2018, Xcel became the first utility to set a long-term goal of providing its customers with zero-carbon electricity.

Excel says an EV powered with its electricity in 2021 was more than 55% cleaner than a conventional gasoline-powered vehicle and is expected to be at least 80% cleaner by 2030.

Earlier this month, the Minnesota-based utility unveiled a transportation vision to provide the infrastructure and energy to run all vehicles in its service area on clean energy by 2050. If the EV drivers in its service area can charge up on net-zero electricity, it can be extrapolated that the clean energy will also be delivered to its residential and commercial customers from Texas to Michigan.

Currently, about 49% of Xcel electricity is generated from carbon-free sources such as wind, nuclear, and solar. The balance comes from natural gas- and coal-fired power plants.

Xcel is looking to Ambri's liquid metal battery technology to help achieve its clean energy goals as the company installs more renewable energy and retires coal plants.

"We are pleased to work with Ambri as we continue bringing our customers the clean, affordable energy they depend on," said Alice Jackson, senior vice president of system strategy and chief planning officer at Xcel Energy.

Liquid metal battery testing

To gain a better understanding of how Ambri batteries can help achieve its renewable energy goals, Xcel will test the liquid-metal battery technology at Solar Technology Acceleration Center. As the largest solar technology test facility in the United States, SolarTAC offers a world-class venue for researching, demonstrating, testing, and validating solar-range technologies at the early commercial or near-commercial stage of development.

The liquid-metal batteries developed by Ambri have a calcium alloy anode, a molten salt electrolyte, and an antimony cathode.

Ambri Inc.

Trays of individual Ambri liquid-metal battery cells are loaded into containers to create an energy storage system that offers a low-cost, reliable, and safe alternative to lithium-ion batteries for grid-scale renewable energy storage.

At room temperature, Ambri's cell is nonconductive, and its materials are solid. However, once heated to 500 degrees Celsius (932 degrees Fahrenheit), the minerals and metals melt and become active. The passing of ions through the electrolyte as the battery charges and discharges keeps the metals molten, eliminating the need for auxiliary heating or cooling.

All these liquids are stored in a single stainless-steel tank without the need for dividers because, like oil and water, they have different densities and do not mix.

Ambri says these batteries are less expensive to manufacture, work in a wider range of climatic conditions, last longer, and are safer than their lithium-ion counterparts, which makes them ideal for the grid-scale storage Xcel is seeking to trade in its coal plants for solar and other clean energy sources.

To better understand this potential, Xcel is carrying out a year-long test of Ambri battery technology at SolarTAC's testing facility in Aurora, Colorado.

"We look forward to learning what their technology can accomplish in a range of extreme environmental conditions as we look to build out the long-duration energy storage that will help us reach our carbon reduction goals," said Jackson.