In much of the developed world, air-conditioning in buildings is the dominant driver of summer peak electricity
demand. In the developing world a steadily increasing utilization of air-conditioning places additional strain on
already-congested grids. This common thread represents a large and growing threat to the reliable delivery of
electricity around the world, requiring capital-intensive expansion of capacity and draining available investment
resources. Thermal energy storage (TES), in the form of ice or chilled water, may be one of the few technologies
currently capable of mitigating this problem cost effectively and at scale. The installation of TES capacity allows
a building to meet its on-peak air conditioning load without interruption using electricity purchased off-peak and
operating with improved thermodynamic efficiency. In this way, TES has the potential to fundamentally alter
consumption dynamics and reduce impacts of air conditioning. This investigation presents a simulation study of
a large office building in four distinct geographical contexts: Miami, Lisbon, Shanghai, and Mumbai. The
optimization tool DER-CAM (Distributed Energy Resources Customer Adoption Model) is applied to optimally
size TES systems for each location. Summer load profiles are investigated to assess the effectiveness and
consistency in reducing peak electricity demand. Additionally, annual energy requirements are used to determine
system cost feasibility, payback periods and customer savings under local utility tariffs.