Optimal energy management of microgrids incorporating hybrid energy storage systems

Abstract: An increase in the search for electricity from renewable energy sources (RES) like solar, wind, tidal and geothermal sources has become important in improving access to reliable and affordable energy worldwide. The challenge with their use, however, is that the electricity supply is intermittent, thus posing a challenge to energy system planners. Storage systems may be incorporated within the power system to address this intermittency and handle the varying power surpluses or deficits provided by these renewable sources. Although it has been established that storage systems can improve the reliability of a network, encourage the penetration of RES and reduce peak demand, a major challenge is the high capital costs involved. Thus, this thesis presents three mathematical models to investigate the techno-economic aspects of hybrid energy storage systems (HESS) operating within a power network. The first model, which is reported in Chapter Three, exploits the complementary characteristics of each storage system forming a part of the HESS while considering degradation in energy output. The results present an index, the Levelised Cost of Hybrid Energy Storage Systems (LCOHESS) which informs proper decision making for the HESS configuration to be adopted considering technoeconomic constraints Similarly, the second model, in Chapter Four, examines the multiple revenue streams offered by hybrid storage systems in a prosumer microgrid in an attempt to make a favourable case for the adoption of storage systems...D.Phil. (Electrical and Electronic Engineering Science