REVIEW ON THERMAL ENERGY STORAGE SYSTEMS

Abstract

In the past five thousand years human energy consumption per capita has risen from 9 to 230 kWh/capita.day. At the current rate of usage, taking into consideration population increases, natural resources will be depleted within a few decades. One must therefore endeavour to take precautions today for a viable world for coming generations. There are many situations where available energy is wasted because it is in the wrong place and/or at the wrong time. Therefore, there is a desperate need for energy storage and a very wide range of techniques is used for this purpose. Most methods involve high capital investment; however, so a cheaper alternative has been widely exploited in which thermal energy is stored in a suitable medium. Sensible and latent heat thermal storage systems in general have been among main topics in research for the last two decades or so, but although the information is quantitatively enormous, it is also widely spread in the literature, and often quite difficult to find. This work provides a survey of studies dealing with thermal energy storage (TES) using sensible and solid–liquid phase change thermal energy storage units. Three aspects have been the focus of this review: storage media, heat transfer analysis and applications. The work described below falls within an area of international interest as it deals with energy saving, the efficient and rational use of available resources and the optimum use of renewable energies.