With the prevalence of Electric Vehicles (EVs)

a large number of on-board lithium batteries will be retired from EVs in the future. These Second-life Battery (SLBs) usually still preserve 70%–80% of their original capacities and have potential to be reutilized in the power system. However

at present

users in power systems such as renewable energy producers have little enthusiasm on SLBs

as the lifetime of SLB is usually shorter than a fresh battery and consistency of the SLBs' performance is not as good as the fresh battery. To address above issues

this paper proposes a SLB utilization model based on the concept of Cloud Energy Storage (CES)

namely SLB-based CES. In the SLB-based CES

the SLB is shared by multiple renewable energy producers. In order to comprehensively analyze the profit and investment risk of each participant in the CES system

the optimal scheduling model of the CES system is proposed. Multiple business models for the SLB supplier are designed. Economic analysis is carried out based on actual power system profiles from Western Inner Mongolia

China. Simulation results verify that the proposed SLB-based CES model can reduce energy storage utilization cost and mitigate the investment risk which is originally undertaken by energy storage users.