Parked EVs and water heaters could turn cities into giant batteries

New research from the Australian National University (ANU) demonstrates that electric vehicles (EVs) and household hot water systems could transform cities into large-scale distributed energy storage (DES) hubs, significantly strengthening electricity grids. By intelligently managing the timing of EV charging and water heating, residents in fully electrified cities like Canberra could collectively store and redistribute energy equivalent to owning 3–4 Tesla Powerwall batteries per person (around 46 kWh). This load shifting to off-peak hours could reduce peak electricity demand by up to 50%, easing infrastructure stress and enabling better use of rooftop solar energy to meet evening demand. The study highlights the importance of DES in supporting grid stability as cities transition to renewable energy and electrify transport and heating, which are major contributors to greenhouse gas emissions globally. Using the Australian Capital Territory (ACT) as a case study—an area already running on 100% renewable electricity and aiming for net-zero emissions by 2045—the research employs detailed hourly and suburb-level energy