Wednesday, 19 May 2021 Malta Inc. is teaming up with Duke Energy to study the socioeconomic, environmental and operational benefits of converting retiring coal units into long-duration, zero-emissions energy storage systems by integrating Malta’s 100-megawatt, 10-hour pumped heat energy storage system into existing infrastructure at a Duke Energy coal plant in North Carolina. Courtesy of Duke Energy A U.S. Department of Energy grant is funding the year-long study of the emerging technology. Malta is developing a pumped heat energy storage system that leverages well-understood subsystems, components and thermodynamics in a novel energy storage application. By leveraging existing subsystems from well-established industries, the system relies on decades of performance data to ensure safe, resilient operations.