Storing electricity as thermal energy at community level for demand side management

Direct electrical energy storage can play a pivotal role in the efficient grid integration of renewable energy resources and compensating temporary power surpluses and shortages, however it is needed to move beyond the single sector focus and electricity’s conversion to other storable forms of energy should not be neglected in efforts to find the optimal solutions for maintaining the momentary balance between electricity supply and demand. This paper discusses the benefits of storing electricity as thermal energy over direct electricity storage. A community located in a hot climate region is considered as a case study and the performance of cold thermal storage and direct electricity storage are compared for it. For this purpose, the hourly performance of the storage systems during each year is modeled and particle swarm method is used to solve the optimization problem. Results show that storing electricity as thermal energy shows a much better performance over direct electricity storage. It requires much less investment, has a higher net present value and results in a flatter load profile. The paper also investigates the effects of electricity pricing structure, economies of scale and battery cost reduction on the economic performance of both thermal and electricity storage systems.