A promising approach for chemical energy storage from fluctuating renewable electricity is methanol synthesis from CO2 and hydrogen in a slurry reactor concept, due to efficient heat storage and easy reactor control. In combination with a promising In2O3/ZrO2 catalyst and mineral oil as carrier liquid, efficient methanol production under a wide range of changing process conditions is shown for the first time. A maximum methanol productivity of 2.1 g(MeOH)g(In)(-1)h(-1) and multiple recycling stability of the catalyst and the carrier liquid was achieved, showing no significant decrease in methanol yields.