This paper presents the results of an experimental and numerical study on ice banks of the parallel plate type with the objective of identifying the relative importance of the geometrical and operational parameters and their influence on the performance of the ice bank. The model is based upon one dimensional formulation of the phase change problem and its numerical solution was realized using the finite difference method and a fixed grid scheme. The model predictions were compared with experiments, an analytical solution and an approximate model based upon the integral heat balance method. The energy stored, the interface position and the time for complete solidification are presented and discussed in terms of the initial temperature of the phase change material, the wall temperature of the cold plate and the gap between the plates. The effectiveness acid NTU of the experimental unit are also presented and discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.192163193