A Vanadium redox flow battery test facility of industrial size (IS-VRFB) has been recently built at the Energy Storage and Conversion Laboratory of University of Padua in order to investigate the performance potential of scaling-up from small-scale single-cell bench experiments. The facility is built around a 40-cell 600-cm 2 active-area stack and two 550-litre tanks. The facility is provided with advanced electronic bidirectional power supply, multi-physics instrumentation and data acquisition and control system. This paper reports on the experimental results obtained so far. Two working modes were tested, i.e. fast and steady-state discharge, representative of real operative conditions, such as primary frequency regulation and peak shaving, respectively. During discharge tests at SOC=0.9 on a passive load, currents as high as 400 A (665 mA cm– 2) where measured at a specific flow rate of 20.5×10–3 cm s–1, with a steady state value in excess of 350 A (of 583 mA cm–2). Maximum power exceeded 9 kW (370 mW cm–2 per cell), with a steady state value approaching 8 kW (330 mW cm–2 per cell). Energy losses measurement showed a round trip efficiency (RTE) in excess of 70%. This performance required a proper programming of the control strategies provided by the system supervisor. References Alotto, M. Guarnieri and F. Moro, “Redox flow batteries for the storage of renewable energy: A review,” Renew Sus. Energ Rev. 29, (2014): 325–335.Guarnieri, A. Trovò, A. D’Anzi, P. Alotto, “Developing vanadium redox flow technology on a 9-kW 26-kWh industrial scale test facility: design review and early experiments”, Appl Energy, 230 (2018) 1425-1434. DOI: 10.1016/j.apenergy.2018.09.021.Trovò, G. Marini, A. Sutto, P. Alotto, M. Giomo, F. Moro, M. Guarnieri, “Standby thermal model of a vanadium redox flow battery stack with crossover and shunt-current effects”, Appl Energy, 240 (2019) 893-906.Trovò, A. Saccardo, M. Giomo, F. Moro, M. Guarnieri, “Thermal modeling of industrial-scale vanadium redox flow batteries in high-current operations”, J Power Sources, in print. Figure 1