This work proposes a systems optimization control model for energy management of a parallel crushing process made up with high-pressure grinding rolls (HPGR) machines. The aim is to reduce both energy consumption and cost through optimal control of the process and load shifting, respectively. A case study of a copper crushing process is solved under three scenarios in order to evaluate the effectiveness of the developed model. Simulation results show that 41.93% energy cost saving is achieved through load shifting by coordinating the rotational speed of HPGRs. It is further shown that the energy saving can be achieved when the two HPGRs are not operated with equal overall efficiency, but also through a small decrement in rolls operating pressure. In the first case, 1.87% energy saving is obtained while in the last case, about 4.5% energy saving is achieved for every decrement of 0.2 N/mm(2) in rolls operating pressure without significant change in product quality. (C) 2015 Elsevier Ltd. All rights reserved.