A direct electrochemical refrigeration cycle (DERC) uses the entropy change of an electrochemical reaction to produce cooling. The cycle is Carnot limited. The electricity recycled in the DERC is much larger than the energy input to the system. Therefore, the system is sensitive to small inefficiencies in the internal energy cycling. In addition, a DERC is modelled assuming that the electrochemical cells have a constant internal resistance. By modelling the electrodes as parallel plates, an optimal channel size on the order of tens of microns can be computed depending on the electrical resistivity and viscosity of the electrolyte. The maximum cooling flux is on the order of 1000 W m(-2). Copyright (c) 2006 John Wiley & Sons, Ltd.