Study on the investment and construction models and value assessment of shared energy storage in the context of the new power system

New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China. In the “14th Five-Year Plan” for the New Energy-Storage Development, it is proposed to expand investment and construction models by promoting the deployment of energy-storage facilities through the ways of self-construction, leasing, and purchasing, and to encourage the development of the shared energy-storage. However, the current scarcity in the model of the shared energy-storage investment and construction substantially restricts its development, particularly due to unclear mechanisms for cost and benefit allocation, which also discourages potential investors. To address the issues, this paper proposes investment and construction models for shared energy-storage that aligns with the present stage of energy storage development. In specific, three main models are introduced: (1) Centralized Self-built Shared Energy-Storage model (CSSES), (2) Third-party Investment Shared Energy-Storage model (TISES), and (3) Distributed Self-built Shared Energy Storage (DSSES) model. The cost–benefit analysis is conducted for each model. The results indicate that the CSSES model achieves the highest internal rate of return (11.5%) and the shortest payback period, while the DSSES model performs acceptable with an IRR of 9.4%. In contrast, the TISES model shows the lowest IRR (6.7%) and requires higher electricity price for being viable. Furthermore, the study employs the entropy weight method and the analytic hierarchy process (AHP) for indicator evaluation, and integrates the technique for order preference by the similarity to an ideal solution (TOPSIS) for scheme optimization. The results show that both the CSSES model and the DSSES model achieve the highest proximity scores. Under environmental regulations, these models demonstrate superior economic benefits by optimizing energy storage utilization, reducing user costs, and enhancing overall profitability.