Investment Decision-Making Using Probabilistic Life Cycle Costing – Comparing Flooded Lead-Acid and Lithium Ion Batteries for Power Supply Backup in Substations

Abstract

During a power outage, substations require a power supply back-up in form of batteries to resume the control functionality. Traditionally, Flooded Lead-Acid (FLA) batteries are utilized in substations as power back-up. Even though new battery technologies have emerged, it is still the battery of choice. Lithium-Ion (Li-Ion) batteries have found wide acceptance in other areas but rarely as power back-up in substations. This is due to the high initial investment costs and the lacking experience in operation. In this study, we compare the FLA and Li-Ion batteries with a probabilistic life cycle analysis that considers both the capital costs and operational costs occurring over the whole life cycle. Applying probabilistic models and Monte Carlo simulations, the net present value can be presented as a distribution. The resulting distribution considers the risk and uncertainties in the input parameter and therefore enables a better decision-making. The results of this study shows that the Li-Ion battery has the lower average life cycle costs with a lower uncertainty.