The possibilities of energy storage in bulk materials

The increased demand for energy from renewable sources entails the development of storage systems. The purpose of these systems is to supply energy on demand during periods which may not be concurrent with the time of the most efficient production of this energy. Various systems are being developed for storing energy in various forms and over various lengths of time.This paper presents selected projects and the results of studies into thermal energy storage. The results of the present author's own research into the transport of thermal energy in granular beds are also presented. The curves of temperature distribution have been determined; they are essential for the design of the thermal storage of a granular bed. Such curves need to be determined for the given granular bed and for the conditions of its operatio