Energy storage technologies as techno-economic parameters for master-planning and optimal dispatch in smart multi energy systems

Smart multi-energy systems based on distributed polygeneration power plants have gained increasing attention for having shown the capability of significant primary energy savings and reduced CO2 pollutant emissions due to the high renewable energy sources penetration. Compared to the traditional power plants, the large variability in the end-user demands (electricity, heat and cold energy), coupled with the uncertainty in the solar and wind energy availability, require the adoption of energy storage systems for dampening the intermittency problems and for performing peak shaving. In a multi-energy system, energy storage technologies typically exist in the form of electrochemical energy and thermal energy storage. Costs and technological limits of energy storage systems are the key parameters that influence the optimal design and operation of the system. In this paper, by adopting an in-house developed simulation tool ((c) E-OPT) based on mixed integer quadratic programming, a sensitivity analysis has been carried out for investigating the techno-economic impact of different storage technologies (i.e. lithium-ion, Vanadium redox, ice and phase change material thermal storage) for optimally designing and operating a multi-energy system. Two case studies, characterized by electricity and peak cooling demand of 1600 kWe and 3000 kWc respectively, have been assessed and the results of master-planning and optimal dispatch discussed for two scenarios, grid-connected and island mode. The results show that multi-energy systems which include combined heat and power units, solar PVs and energy storage systems lead to achieve more than 1.1 $M and 4.5 $M savings in net present value and 15% and 25% reduction in CO2 emissions, when compared with traditional power plant generation.