Techno-economic assessment and mechanism discussion of a cogeneration shared energy storage system utilizing solid-state thermal storage: A case study in China

Energy storage plays a vital role in balancing the gap between energy supply and demand in emerging energy systems. Previous studies primarily focused on the electrochemical energy storage, but less stressed on the electricity and heat demand from terminal-users. This paper aims to address this gap by proposing a novel shared energy storage system for cogeneration. A typical cogeneration shared energy storage (CSES) system utilizing the solid-state thermal storage is developed, and an optimization model maximizing economic benefits is formulated for scrutinizing the practicalities of multi-mode operations in the given scenario. Through the case study, we have determined that the internal rate of return (IRR) of the system is 10.2 %, while the payback period stands at 8.4 years. Furthermore, the key factors and their respective impacts on the system's economic performance are revealed, such as the capacity rental fees, peak-valley price differential, heating revenue, and downtime. In addition, extensive discussions are conducted regarding crucial issues including the assessment of storage capacity equivalence in CSES systems from the technical and market perspectives, as well as considering the rationality of diversified revenue streams.