The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), in partnership with Blue Frontier Inc., has introduced a breakthrough cooling technology that could transform how buildings use energy. The Energy Storing and Efficient Air Conditioner (ESEAC) integrates cooling, humidity control, and energy storage in one system, cutting peak electricity demand for air conditioning by more than 90% while reducing annual cooling costs by up to 45%.
“This is a large step forward for air conditioning,” said Eric Kozubal, NREL senior engineer and co-inventor. “It’s a complete rethinking of how we condition air—and when we use electricity to do it.”
Unlike conventional air conditioners that rely on energy-intensive vapor-compression cycles, ESEAC separates dehumidification from cooling using a liquid desiccant system and ultraefficient evaporative cooling. The system stores energy by splitting and storing a salt-based desiccant solution and pure water, which can later be used to cool and dehumidify air during peak demand periods without running compressors.
A year-long simulation in Miami showed that a 20-ton ESEAC unit reduced cooling electricity use by 38%, peak demand by 93%, and electricity costs by 45%—amounting to an estimated $165,000 in savings per unit over 15 years.
Early installations are underway at U.S. Army bases, universities, hospitals, and commercial sites, with backing from Breakthrough Energy Ventures, Volo Earth, and other major investors.
By shifting cooling loads away from peak hours, ESEAC also supports grid stability at a fraction of the cost of battery storage. “Air conditioning is a top driver of peak demand,” said Achilles Karagiozis, director of NREL’s Building Technologies and Science Center. “ESEAC stores energy when it’s cheap and uses it when it’s expensive—delivering grid benefits at far lower cost than batteries.”
The system recently won an R&D 100 Award and is being hailed as a new class of cooling technology with the potential to reshape building energy use nationwide.
