Valley Children’s Hospital in Madera, California is retiring its diesel generators in favour of a solar microgrid with long-duration energy storage, in a bid to clean up its electricity supply while ensuring a reliable, uninterrupted flow of power.
The Children’s Hospital Resilient Grid with Energy Storage (CHARGES) project will feature a 34.4-megawatt-hour, long-duration storage system using zinc-bromine flow batteries supplied by Brisbane, Australia-based Redflow Ltd., Power Engineering reports. “The microgrid system is designed to safeguard critical hospital operations during utility outages, ensuring at least 18 hours of continued functionality following earthquakes or other natural disasters.”
The hospital is located in California’s Central Valley, where it “frequently faces extreme environmental challenges, including heatwaves, droughts, smog, and poor air quality,” the news story states. “California has a goal of installing 45 to 55 gigawatts of long-duration energy storage by 2045 to support grid reliability and clean energy adoption.”
The project is one of 15 across 17 states plus the Red Lake Nation in Minnesota that will share US$325 million in U.S. Department of Energy funding, all focused on “battery types that can help turn solar and wind energy into 24-hour power,” The Associated Press writes.
“Batteries are increasingly being used to store surplus renewable energy so that it can be used later, during times when there is no sunlight or wind,” AP explains. “The department says the projects will protect more communities from blackouts and make energy more reliable and affordable.”
“Everywhere in the U.S. has issues with intermittent renewable energy,” said Christopher Rahn, professor of mechanical engineering at Pennsylvania State University. “Every day the sun sets and you have to be able to take the energy that you produced during the day and use that at nighttime.” The focus on long-duration storage reflects growing interest in systems that can run longer than the four-hour span available from most lithium ion batteries.
“Long-duration battery storage is like a rainy day savings account for energy storage,” Jodie Lutkenhaus, a professor of chemical engineering at Texas A&M University, told AP. “As long as these batteries use Earth-abundant materials that are readily available, I do not see any drawbacks.”
The announcement is just one in a continuing series focused on different types of long-duration storage batteries. Less than a week before the DoE announcement, the Sacramento Municipal Utility District said it had taken delivery on a first batch of batteries, supplied by cleantech company ESS, that will eventually go into a 200-megawatt/2-gigawatt-hour long-duration storage system, the company’s biggest installation to date.
The project will be an “early utility-scale test for flow batteries, which store energy by circulating liquid electrolytes and can cheaply scale up their tanks to add hours of extra storage capacity,” Canary Media says. “Some flow batteries use nasty or expensive materials in their liquid electrolytes; ESS instead chose readily available iron to safely and economically store clean energy for longer periods of time than conventional lithium-ion batteries.”
ESS’ battery manufacturing is located in Oregon.