The Chinese government has set long-term carbon neutrality and renewable energy (RE) development goals for the power sector. Despite a precipitous decline in the cost of RE technologies, the external cost of renewable energy intermittency and massive investments in additional RE capacity would increase electricity costs. In a recent study, a power system expansion model was developed to comprehensively evaluate changes in the electricity supply cost over a 30-year transition to carbon neutrality. RE supply curves, operating security constraints, and characteristics of various generation units were modeled in detail to assess the cost variations accurately^[1].