Life-cycle assessment of batteries for peak demand reduction

Abstract

At present, a life-cycle assessment of energy storage systems (ESSs) is not widely available in the literature. Such an assessment is increasingly vital nowadays as ESS is recognized as one of the important equipment in power systems to reduce peak demands for deferring or avoiding augmentation in the network and power generation. As the battery cost is still very high at present, a comprehensive assessment is necessary to determine the optimal capacity of ESS so that the maximum financial gain is achievable at the end of the batteries’ lifespan. Therefore, an effective life-cycle assessment is proposed in this paper to show how the optimum capacity of ESS can be determined such that the maximum net financial gain is achievable at the end of the batteries’ lifespan when ESS is used to perform peak demand reductions for the customer or utility companies. The findings reveal the positive financial viability of ESS on the power grid, otherwise the projection of the financial viability is often seemingly poor due to the high battery cost with a short battery lifespan. An improved battery degradation model is used in this assessment, which can simulate the battery degradation accurately in a situation whereby the charging current, discharging current, and temperature of the batteries are intermittent on a site during peak demand reductions. This assessment is crucial to determine the maximum financial benefits brought by ESS.

Keywords

• Degradation estimation
• Maximum net savings
• Peak demand reduction
• State of health (SOH) estimation