Biogas can be used for complementary load-balancing with renewable intermittent power, thus maintaining overall energy output stability. However, biogas load balancing is typically used in small-scale distributed energy systems, constrained by factors such as technology and land requirements, making it challenging to scale up. Therefore, this study proposes a closed-loop ecological cycle system, where biogas provides load leveling support for large-scale intermittent power sources in desertified regions dominated by animal husbandry. The biogas slurry and residue produced are used for land restoration and subsequent cultivation of high-quality economic crops, with the resulting straw used for the next round of biogas production. This study conducts an economic assessment of the aforementioned system and analyzes a case study of a load-balancing biogas project in Northwest China. Accounting results indicating that the system's net present value is 0.108 million yuan/m