Methodology for BESS Design Assisted by Choice Matrix Approach

Abstract

Battery Energy Storage Systems (BESS) can provide several ancillary services to renewable energy-dominated power systems. However, the choice of the battery employed in the projects is not a straightforward task, since there are several criteria that should be taken into account. Thus, six criteria are considered in this work: the system dc-link voltage, battery lifetime, battery bank volume, battery bank power losses, battery bank price and storage capacity index. The last criterion is related to the BESS energy storage capacity during one-year mission profile operation, which depends on the battery selected for the project. The Multiple Criteria Decision Making (MCDM) is used to choose the best battery based on the relative importance between the Operational Expenditure (OPEX) and Capital Expenditure (CAPEX) concepts. The methodology proposed in this work was applied to 27 batteries composed by lead-acid and Li-ion batteries aiming to select the best solution for a Photovoltaic (PV) system with storage energy based on the peak shaving operation mode. Considering the CAPEX with more relative importance, a lead-acid battery bank was found to be the best solution. On the other hand, when the OPEX is considered more important, a Li-ion battery bank was selected as the best solution.

Keywords

• battery selection
• capex
• decision matrix
• opex concepts
• bess design