An Optimisation Framework for Shared Autonomous Electric Vehicles as Mobile Energy Storage Systems

ABSTRACT Shared autonomous electric vehicles (SAEVs) can function as mobile energy storage systems (ESSs) through vehicle‐to‐grid (V2G) technology, enabling a dual‐purpose role that integrates passenger mobility and grid energy support. To fully leverage this potential, this study develops a high‐level optimisation framework from the fleet operator's perspective based on an analytical model that captures macroscopic fleet operations and energy dynamics. The framework jointly determines the optimal system‐level fleet size and hourly V2G charging and discharging schedules to minimise daily operating costs while satisfying mobility service requirements and battery state‐of‐charge constraints. The model is applied to two urban environments, San Francisco and Seoul, which exhibit contrasting demand patterns, vehicle speeds and electricity pricing dynamics. The results show that electricity price variability is a key determinant of the effectiveness of SAEVs as mobile ESSs. In San Francisco, V2G discharging yields meaningful cost reductions and enables substantial energy exchange with the grid, whereas the benefits are limited in Seoul under relatively stable electricity prices. Sensitivity analyses further indicate that charging efficiency and the price differential between electricity charging and discharging critically shape both economic viability and operational feasibility.