The research group of Thermal Engineering and Thermodynamics of the Institute for Energy Systems and Thermodynamics at TU Wien, has in cooperation with company partner Echogen Power Systems, opens an external URL in a new window from Akron, Ohio, USA, successfully operated and analyzed the second generation (2.0) of the sandTES energy storage concept. In a project funded by the U.S. Department of Energy ARPA-E (program DAYS, project DE-AR0000996), several infrastructure components of the first generation (1.0) test rig in Vienna were re-used in the new installation in Akron. The concept 2.0 employs a new 200kW-t fluidized bed heat exchanger design which allows a substantial performance improvement (heat transfer coefficient, volume, auxiliary power,) compared to the prior solution (1.0). This opens the field for competitive applications employing water/steam, sCO2 or pressurized air as process fluids. The tests in Akron allowed validating results from smaller scale test rigs and gathering operational experience which is essential for the design and further scale-up of the technology.