As more Aussies plug in electric vehicles (EVs) and swap out gas hot water systems for electric ones, there’s growing concern that the surge in electricity use might overload our power grids. With national electricity demand expected to double by 2050, the worry isn’t unfounded — especially if everyone charges up and cranks the heat at the same time.
But here’s the twist: this electric future might not be a problem. It could actually be part of the solution.
The Hidden Power of Everyday Appliances
Switching to electric isn’t just about ditching petrol and gas. It also creates a massive, distributed energy storage system, right in our homes and driveways. EV batteries and electric hot water systems can both store energy — EVs with their large battery packs, and hot water systems by storing heat.
Put together, this adds up quickly. In a fully electrified Australia, each person might be packing around 46 kilowatt-hours of storage capacity. That’s enough for some serious backup. Scaled across the country, we’re talking more than 1,000 gigawatt-hours — dwarfing even Snowy 2.0 and all our grid-scale batteries combined.
Smarter Use, Not Just More Power
So what do we do with all that potential? If it’s harnessed wisely, we can transform cities from energy-hungry consumers into flexible energy hubs. That means shifting when and how we use electricity — like charging EVs and heating water during off-peak times, when the grid isn’t under pressure.
Without any planning, all this new demand could push peak electricity loads up by 34%, forcing costly upgrades to substations and transmission lines. But if we get smart and time our usage right, that peak load increase could be halved — a difference worth billions in avoided infrastructure costs.
Canberra Shows What’s Possible
Take Canberra as a test case. Already powered 100% by renewable electricity since 2020, the ACT aims to hit net zero by 2045. Modelling suggests it could get there faster by using existing storage more cleverly.
By shifting car charging and water heating to low-demand periods, each person’s usage could be reshaped by about 5 kWh per day — roughly a third of their total daily electricity use. That shift also helps keep the grid stable and makes better use of renewable power that might otherwise go to waste.
Interestingly, these new “storage hotspots” don’t stay in one place. During the workweek, battery power tends to shift to city office areas where EVs are parked. Some districts see storage capacity jump by up to 31%. It makes sense, then, to install smart chargers and create “virtual power plants” — systems that coordinate when and how electricity is used across a bunch of homes and vehicles.
What Needs to Happen
The technology is ready. South Australia’s Virtual Power Plant is already proving it can work. But most Aussie homes still don’t have smart chargers or flexible energy systems. In many places, electricity pricing remains too rigid to encourage smarter use.
To unlock the full potential of these everyday energy storage tools, we need:
- Wider use of smart chargers and heaters that can shift usage to when it’s cheapest and greenest.
- Dynamic pricing that reflects real-time demand and supply, giving households a nudge to use energy when it’s plentiful.
- More workplace EV charging in dense city areas, making it easier to plug in during daytime solar peaks.
- Smarter energy networks that can group household systems into one big, flexible energy resource.
Not Just Users — We’re Energy Partners Now
Australia’s electrification journey isn’t just about cutting emissions. It’s about reshaping how we think about power. Cities, households, even humble hot water systems are becoming active players in a cleaner, smarter energy system.
Used right, your EV or hot water system isn’t just keeping you moving or warming your shower. It’s helping to keep the lights on for everyone — and shaping Australia’s energy future for the better.
Article information source: The Conversation - How EVs and electric water heaters are turning cities into giant batteries
