Optimal energy management in all-electric residential energy systems with heat and electricity storage

Abstract

Residential demand profiles typically demonstrate a mismatch between energy demand and PV supply. Different solutions are proposed, such as demand side management and energy storage systems. Nevertheless, costs and environmental impacts of some technologies (e.g. batteries) are high. This paper proposes two system designs: Home Energy Storage (HES) and Community Energy Storage (CES). Besides electricity storage, heat storage is used in the two system designs to supply domestic hot water and space heating. Furthermore, the trade-offs between the different storage mediums in relation to costs are analyzed. To achieve that, different methodologies are used to size the electricity and heat storage mediums for HES and CES. Next, a multi-objective mixed integer linear programming model is developed to optimize the operation costs and CO2-emissions for each system design. After that, the model is tested on a residential community situated in Cernier (Switzerland). The results demonstrate that CES performs better than HES on economic and environmental performance due to economies of scale and the optimally sized storage capacity of the battery in CES. Currently, none of the proposed system designs is economically feasible. However, the sensitivity analysis shows that a profitable system design can be obtained for both HES and CES, when the electricity storage (i.e. battery storage) size is reduced and the heat storage (i.e. water storage tank) size is increased.