Electrified cities could become giant batteries: ANU study  

Our electric vehicles (EVs) and hot water systems could become powerful assets for the electricity grid and help turn Australian cities into giant batteries, new research from The Australian National University (ANU) has found. 

According to lead author Dr Bin Lu, when used smartly, these technologies can help reduce strain on the grid during peak usage times. 

“Cities are often seen as energy-hungry giants,” Dr Lu said.  

“But with widespread electrification, they could also become giant batteries — managing energy, not just consuming it.” 

The study, published in Renewable Energy, uses the Australian Capital Territory (ACT) as a case study to explore flexible energy potential in cities. The research uses travel data, electricity demand profiles and geospatial mapping to evaluate how EVs and hot water systems can shift energy use so it is optimally distributed across time and location.  

The results are striking. In a fully electrified city, each resident could effectively own around 46 kilowatt-hours (kWh) of energy storage, equivalent to three to four home batteries like the Tesla Powerwall. 

By adjusting the timing of charging and heating, each person could shift around five kWh of electricity per day to off-peak hours. This flexible energy represents about one-third of the average daily per capita electricity use, and can be timed to support the grid, rather than strain it. 

“Electric vehicles spend about 90 per cent of their time parked,” Dr Lu said.  

“That’s not a bug. It’s a feature. With smart coordination, these parked vehicles can become a powerful tool to help balance the grid.” 

The research also highlights a critical challenge. If electric loads aren’t managed, peak demand could jump by more than 30 per cent as homes switch to electric cars and heating. That would require expensive network upgrades. 

But by shifting just half of that load to off-peak hours, the increase in peak demand could be halved. This not only helps reduce infrastructure stress but also allows for better use of rooftop solar by storing energy to meet the evening peak in demand. 

The research also identifies “storage hotspots”, high-density employment areas where flexible demand is both high and valuable. These areas present strong opportunities for smart workplace charging, dynamic pricing incentives, and digital platforms that coordinate thousands of small devices to act like a virtual power plant. 

Co-author Associate Professor Marnie Shaw said the study shows how a city like Canberra can take the lead in energy innovation.  

“As we electrify our homes and our transport, we want to make best use of the grid infrastructure we already have, and minimise the need for expensive grid upgrades,” Associate Professor Shaw said.

The modelling was supported by the Icon Water and ActewAGL Endowment Fund and developed in collaboration with Evoenergy, using high-resolution data to map flexible capacity across urban neighbourhoods. 

Acting General Manager of Evoenergy Sam Sachse said the findings will help inform future grid planning.  

“The energy transition is complex with many moving parts. Understanding how these new electric loads behave and how we can manage them is crucial to building a smarter and more reliable electricity network,” he said. 

As countries seek to meet climate targets and accelerate the clean energy transition, this research points to a new path: enabling homes, cars and hot water systems to plug in, heat up, and help power the grid.