Economic Evaluation of the Full Life Cycle of Source-Grid-Load-Storage Projects Based on a Multi-Stage Stochastic LCC-Profit Flow Coupling Model

The economic evaluation of source?grid?load?storage integrated projects predominantly relies on deterministic life?cycle frameworks, which cannot jointly characterize the stochastic evolution of electricity price mechanisms, the nonlinear degradation of energy?storage capacity and dynamic battery?replacement decisions. Consequently, evaluation results can hardly meet the demands of high?risk investment judgment. This paper constructs a multi?stage stochastic LCC?revenue?flow coupled model. On the cost side, three phases including construction, operation and decommissioning are divided, and a temperature?cycle coupled nonlinear degradation model is adopted to characterize energy?storage attenuation; dynamic programming is employed to solve the optimal battery?replacement timing. On the revenue side, the price spread is formulated as a mean?reverting stochastic process to realize the coupling of multiple revenue streams with stochastic electricity prices and degraded capacity. Monte?Carlo method is used to propagate uncertainty, and indicators including NPV, IRR, dynamic payback period and CVaR are output. A total of 3000 simulations are carried out based on a typical case study. The results show that mean?based indicators tend to mislead decision?making; battery?replacement strategies are highly sensitive to electricity?price spreads, and risk constraints will lower the optimal configuration ratio of energy storage. The proposed model extends economic evaluation from point estimation to a composite framework of distribution estimation, strategy optimization and risk constraint, and can provide robust quantitative support for feasibility studies and investment decisions of source?grid?load?storage projects.