Solar thermal power generation requires a cost effective thermal storage system. The existing two tank system is very expensive due to the storage material inventory. The use of phase change materials (PCMs) offers higher storage density. A review of potential PCMs was conducted in order to come up with commercially available ones having suitable properties. Most available PCMs have low thermal conductivity making heat transfer enhancement necessary for power applications. The various methods of heat transfer enhancement in latent heat storage systems were also reviewed systematically. The review showed that three commercially-available PCMs are suitable in the operating temperature range of parabolic trough plants. Many heat transfer enhancement methods have been investigated in the literature but the use of aluminium fins is the most promising in the temperature range of 250-330 o C. Many eutectic mixtures of materials have potential for use but discrepancies exist in their reported melting temperature and latent heat of fusion.Keywords: Latent heat, high temperature, thermal conductivity enhancement 1. INTRODUCTION Solar thermal power generation is one the most sustainable and renewable source of electricity. It has the potential of fulfilling the world's electricity needs due to the availability of solar energy in sufficient quantity in various regions of the world [1 -3]. Various solar thermal technologies have been developed over the years for the generation of electricity [4]. The parabolic dish [5 -7] power tower [8,9] and the parabolic trough [10 -12] are the most advanced and have been commercialized. The parabolic trough technology using synthetic oil as the heat transfer fluid (HTF) with operating temperature range between 290 and 400 o C is the most matured and cost effective technology for capacities <200 MW. This can partly be attributed to the experience gained in the operation and maintenance of the 354 MW Solar Electric Generating Station (SEGS) plants for over two (2) decades [4,13]. Most commercial solar plants in operation and under construction are of the parabolic trough technology [9]. The stable and sustainable operation of a solar thermal plant requires a back-up thermal energy source in order to produce thermal energy when that from the sun is insufficient. For cost effective operation there is also the need to avoid energy wastage when the