Optimal sizing, operation, and efficiency evaluation of battery swapping stations for electric heavy-duty trucks

Ruiting Wang, Yi Ju, Zaid Allybokus, Wente Zeng, Nicolas Obrecht, Scott Moura

2024 American Control Conference (ACC)

For more information please refer to Full Paper.

And the presentation,


Abstract

Decarbonization and electrification of long-haul trucks are notoriously difficult due to the high energy demand and limited gravimetric energy density of lithium-ion cells. In this study, we investigate the optimal deployment and operation of a grid-connected battery swapping station (BSS) for electric long-haul trucks as a mixed-integer optimization problem. We construct a model for reliably meeting customer energy needs while providing grid services, to demonstrate the business case and the operation of such a system. The impact of optimal sizing of the station is explored. A comparative study of two alternative charging infrastructure solutions using battery swapping and fast charging stations (FCS) has been performed through numerical experiments. We examine ton-mile-per-hour as a metric for the relative efficiency of cargo movement and the labor requirements. We find that FCS works better for large battery packs with short and regional hauls, and BSS is well suited for relatively medium-sized battery packs and long-haul truck movements. The study also found that the potential to use smaller batteries, and the expansion of the network can increase the battery utilization efficiency of BSS, which may be able to approach a similar level to the utilization efficiency of FCS.


Main Findings in a Nutshell

In BSS sizing for heavy-duty trucks:

  • The number of batteries needed increases linearly with the frequency of customer visits

To maximize transportation efficiency,

  • For BSS, it is better to have medium sized batteries and use this system for long-haul, because it have generally higher efficiency, and the efficiency does not reduce dramatically with charging events.
  • For FCS, it is more suitable for within a day operation of short or regional hauls, with a large sized battery.

Use smaller battery sizes increases battery utilization for BSS, which may offset the need to purchase and install more batteries

ESTC Best Paper Award

This paper won Energy System Technical Committee Best Paper Award at ACC 2024! Special thanks to my advisor, Scott Moura (first from left).