The paper presents results of the simulation of the effect of some significant factors on energy consumption and specific energy consumption for electrochemical grinding and mechanical grinding of three hard-to-machine materials (sintered carbides B40, titanium alloy Ti6Al4V and steel 18G2A). The investigation has been carried out on models of energy consumption and specific energy consumption for electrochemical and mechanical grinding performed by the grinding wheel face. The results have shown that within the range of parameters and machining conditions employed, mechanical grinding of hard-to-machine materials is characterized by higher energy consumption than electrochemical grinding.