  Battery storage is expected to play a crucial role in the low-carbon
transformation of energy systems. The deployment of battery storage in the
power gird, however, is currently severely limited by its low economic
viability, which results from not only high capital costs but also the lack of
flexible and efficient utilization schemes and business models. Making
utility-scale battery storage portable through trucking unlocks its capability
to provide various on-demand services. We introduce the potential applications
of utility-scale portable energy storage and investigate its economics in
California using a spatiotemporal decision model that determines the optimal
operation and transportation schedules of portable storage. We show that
mobilizing energy storage can increase its life-cycle revenues by 70% in some
areas and improve renewable energy integration by relieving local transmission
congestion. The life-cycle revenue of spatiotemporal arbitrage can fully
compensate for the costs of portable energy storage system in several regions
in California, including San Diego and the San Francisco Bay Area.
