In this article a review of heat storage technologies with phase change materials (PCMs) is given. In addition, we present paraffin as phase change material in solar heat storage wall with proposals of heat transfer enhancement. The mathematical model for heat transport in heat storage is made. The results obtained with the simulation gives the time dynamics of heat accumulation in phase change material with fins as the media for heat transport enhancement. We found out that the most influential of the parameters is the distance between the fins. (C) 2003 Elsevier B.V. All rights reserved.