An assessment of a bench-scale vanadium redox flow battery (VRFB) undergoing an accelerated ageing has been carried out under two operation modes: a galvanostatic-charging mode, where a constant current density was always applied, and solar-panel charging mode, where different current densities were applied according to the solar radiation profiles obtained during three consecutive days in Winter, in Ciudad Real, a town in the center of Spain. The accumulated and delivered charge capacities and the different efficiencies were analyzed. The concentrations of different vanadium ions were also measured. Both modes allow reaching similar efficiencies and charge/discharge capacities but they do not affect in the same way to the accelerated degradation of the performance of the electrochemical cell. Moreover, the ratio power density/energy density was very comparable for the two operation modes tested in this work. These results indicate that VRFBs are suitable devices for the storage of the electricity produced in photovoltaic solar panels.