City-scale integration of distributed energy storage resources for an all-electric energy future

Abstract

Distributed energy storage (DES) resources, such as electric vehicle batteries and hot water storage, can provide significant, currently underutilised, demand flexibility to support the uptake of variable renewable energy sources. However, large-scale assessments of DES resources on a city level are scarce. In this research, a set of methods are developed for high-resolution temporal and spatial assessment using Geographic Information System-based models. An all-electric energy future is modelled for the Australian Capital Territory as a case study, which features one of the world's most rapid transitions towards net-zero emissions. The modelling results show that electric vehicle batteries and hot water storage can provide storage capacities of 43 kWh and 2.6 kWh per capita, respectively. The daily flexibility they provide can reach 3.8 kWh/day and 1.5 kWh/day per capita, equivalent to one-third of the average electricity consumption of 16 kWh/day per capita. The distribution of DES resources is highly dependent on population density and urban growth. Storage capacity varies dynamically with daily travel patterns, rising by 2%–21% during the weekday in workplace-dense districts. Integrating electric vehicles and electric water heating systems may increase electricity consumption by 48% while raising peak load by 34%, indicating an improvement in the utilisation of electricity grid infrastructure from transport and heating electrification. Additionally, various charging and heating strategies could modify the peak load growth to 37%, 16%, and 20% with the daytime, overnight and flat profiles, respectively.