Everyone knows ice is great for chilling drinks on a hot summer day.
But what if the same idea could help cool entire buildings and ease pressure on the power grid?
That’s the promise of “ice batteries,” a form of thermal energy storage that researchers at Texas A&M University are working to make even better.
Dr. Patrick Shamberger, an associate professor of materials science and engineering, studies the materials used in these cooling systems.
In new research published in The Journal of Physical Chemistry C, he and his colleagues explain how the right materials could make ice battery systems more efficient, reliable, and long-lasting.
The idea is simple: water or another material is frozen at night, when electricity demand is low and prices are cheaper.
The stored cold is then used during the day to cool buildings, cutting down on energy use during the busiest hours. Large commercial systems can freeze up to 500,000 pounds of ice each night, which can then keep a building cool the following day.
This approach is not new, but there are challenges. “The ice battery technology has been around for a while,” Shamberger said.
“But there are problems on the material side that I’m interested in: what’s the right material at the right temperature? Can we make it reversible? Can we make it last for 30 years?”
His team is focusing on special compounds called salt hydrates, which are salts that naturally hold water in their crystal structure.
These materials can absorb and release heat at specific temperatures, making them useful for both cooling and heating systems.
By fine-tuning the temperature range, the researchers hope to design materials that work smoothly with heating, ventilation, and air conditioning (HVAC) systems already in use in buildings.
One of the biggest hurdles is something called phase segregation. In many salt hydrate systems, the material separates into different phases—solid and liquid with different compositions—over time. This reduces performance and reliability. By studying the thermodynamics of these materials, the Texas A&M team hopes to find formulas that stay stable through many cycles, potentially lasting decades.
Beyond cutting cooling costs, these systems could also help modernize the energy grid. As more renewable energy sources like wind and solar are added, supply and demand become harder to balance. Instead of building costly new power plants, technologies like ice batteries can shift when energy is used, reducing strain on the grid.
“We don’t want to solve grid problems by building more power plants,” Shamberger explained. “That’s a very costly solution and they’d have to charge higher rates overall.”
Ice battery systems are already in operation, including in the 30-story Eleven Madison building in New York City. With improved materials, they could become far more common, helping cities stay cool, cutting power bills, and supporting a cleaner, more resilient energy future.
