Electric vehicles are changing more than the way Australians drive.
The next evolution could change the way we power our homes.
Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G) technology allows compatible electric vehicles to do more than simply take electricity from the grid. With the right vehicle, charger and electrical system, energy stored inside an EV battery can potentially be sent back into a home — or even back into the electricity grid.
For Australian households with rooftop solar, this creates an interesting possibility:
Your electric vehicle could effectively become a very large home battery.
What Is Vehicle-to-Home Technology?
Vehicle-to-Home, commonly called V2H, is a form of bidirectional charging.
A conventional EV charger sends electricity in one direction:
Grid or solar → EV battery
A bidirectional charging system can potentially move electricity both ways:
Solar/grid → EV battery → home
This means an EV could be charged during the day when rooftop solar production is high and then potentially supply some of that stored electricity back to the home later.
For households that already produce excess solar energy, this could dramatically change how that electricity is used.
What Is Vehicle-to-Grid?
Vehicle-to-Grid, or V2G, takes the same concept one step further.
Rather than supplying electricity only to the home, a compatible EV and bidirectional charger may also be able to export electricity back into the electricity network.
In the future, this could allow thousands of parked electric vehicles to act as a distributed energy-storage network.
During periods of high electricity demand, energy stored inside EV batteries could potentially support the grid.
When electricity demand is lower, or rooftop solar generation is high, the vehicles could recharge.
Why Is This Technology Important for Australia?
Australia has one of the highest rates of rooftop solar adoption in the world.
For many households, a significant amount of solar energy is produced during the middle of the day — often at the same time that household electricity consumption is relatively low.
Without a battery, much of that excess electricity is exported to the grid.
Bidirectional EV charging creates another option.
A future household could potentially:
- generate electricity from rooftop solar during the day
- charge an electric vehicle using excess solar production
- store that energy inside the vehicle battery
- use some of that stored energy to power the home in the evening
- reduce electricity purchased during expensive peak periods
- potentially export electricity back to the grid when appropriate.
Instead of thinking about an electric vehicle purely as transport, we may increasingly begin to think about it as part of the home's energy infrastructure.
How Big Is an EV Battery Compared With a Home Battery?
This is where the technology becomes particularly interesting.
Many dedicated residential batteries have usable capacities somewhere around 10–15 kWh, although systems vary considerably.
Electric vehicle batteries can be substantially larger.
Depending on the vehicle, battery capacities of approximately 50 kWh, 60 kWh, 80 kWh or more are increasingly common.
Not all of that energy would necessarily be available for household use, and system limitations vary, but the potential storage capacity is significant.
For some households, the largest battery they eventually own may actually be sitting in the driveway.
Could You Charge Your EV From Solar and Power Your Home at Night?
Potentially, yes.
Imagine a home with rooftop solar, an electric vehicle and intelligent energy management.
During the middle of the day:
Solar panels generate excess electricity.
Instead of exporting all of that electricity to the grid, the home's energy-management system directs some of it into the vehicle.
Later, when solar production drops:
The home could draw electricity back from the EV battery.
This could reduce the amount of electricity purchased from the grid during higher-cost periods.
The system could also preserve a minimum amount of charge in the vehicle so that sufficient driving range remains available.
Increasingly, these decisions could be made automatically by intelligent home-energy systems.
Could an EV Provide Backup Power During a Blackout?
For compatible vehicles and systems, Vehicle-to-Home technology may potentially provide backup power, although this depends heavily on the specific equipment and installation.
Providing backup power safely requires more than simply connecting an EV to a house.
The electrical system must be capable of safely isolating the property from the electricity grid during an outage and supplying approved household circuits.
Vehicle compatibility, charger capability, electrical configuration and Australian connection requirements all need to be considered.
This means consumers should not assume that purchasing an electric vehicle automatically gives them blackout protection.
Not Every Electric Vehicle Supports V2H or V2G
This is currently one of the biggest limitations.
Bidirectional charging requires support from several parts of the system:
The vehicle must support bidirectional power transfer.
The charger must be capable of transferring electricity both into and out of the vehicle.
The electrical installation must be designed appropriately.
Network and regulatory requirements must also be satisfied.
Standards and compatibility are continuing to develop, so homeowners considering this technology should check the capabilities of the exact vehicle and charging system they intend to purchase.
The Bigger Story: The Smart Energy Home
V2H is only one part of a much larger transformation happening in residential energy.
Traditionally, different household energy systems operate independently.
Solar panels generate electricity.
A battery stores electricity.
An EV charger charges a vehicle.
A hot-water system heats water.
Air conditioning heats and cools the house.
A pool heat pump heats the swimming pool.
But increasingly, these systems can be connected.
A Home Energy Management System (HEMS) can potentially coordinate when appliances operate based on factors such as:
- rooftop solar production
- battery charge levels
- EV battery charge
- household electricity demand
- electricity tariffs
- grid conditions
- weather forecasts
- homeowner preferences.
Instead of simply using less electricity, the future home will increasingly focus on using electricity at the right time.
What Could the Australian Home of the Future Look Like?
Consider a future home equipped with:
☀️ Rooftop solar
🔋 Home battery storage
🚗 Bidirectional EV charging
🔥 Heat-pump hot water
❄️ High-efficiency heating and cooling
🏊 Energy-efficient pool heating
⚡ Smart appliances
🤖 Intelligent home-energy management
During the day, solar electricity could charge batteries, vehicles and thermal systems.
During the evening peak, the home could rely more heavily on stored energy.
Large electrical loads could automatically operate when renewable electricity is abundant or electricity prices are lower.
The individual technologies already exist.
The major emerging opportunity is making them work together intelligently.
Will EVs Replace Home Batteries?
Probably not in every household.
An EV and a dedicated home battery perform different roles.
A home battery normally remains connected to the property and can respond continuously to household electricity demand.
An EV, however, may leave the property during the day or need to preserve significant driving range.
For many households, the future may therefore involve a combination of:
Solar + home battery + EV battery + intelligent energy management.
Rather than one replacing the other, each could become part of a larger integrated energy system.
Is Vehicle-to-Home Available in Australia Now?
Bidirectional charging is developing rapidly in Australia, but availability depends on the vehicle, charger, electricity network and installation.
Australian governments, electricity networks, vehicle manufacturers and energy companies are continuing to trial and develop Vehicle-to-Grid and Vehicle-to-Home technology.
Consumers considering V2H or V2G should therefore check current Australian compatibility and approval requirements before purchasing equipment specifically for this purpose.
Why EcoTech Is Watching This Technology
The biggest change in home energy may not be a single new product.
It may be integration.
Solar, batteries, electric vehicles, heating, cooling, hot water and other major electrical loads are increasingly becoming connected parts of the same household energy system.
That creates an opportunity for homes to become more efficient without necessarily sacrificing comfort.
The next generation of energy-efficient Australian homes won't simply consume less electricity.
They'll become smarter about when they generate it, when they store it and when they use it.
At EcoTech Homes, we'll continue exploring the emerging technologies changing the way Australian homes generate, store and use energy.
Frequently Asked Questions
What is Vehicle-to-Home?
Vehicle-to-Home (V2H) allows a compatible electric vehicle to supply electricity stored in its battery back to a home through an approved bidirectional charging system.
What is Vehicle-to-Grid?
Vehicle-to-Grid (V2G) allows a compatible electric vehicle to potentially export stored electricity back into the electricity network.
Can an electric vehicle power a house?
Some compatible electric vehicles can potentially provide electricity to a house when used with appropriate bidirectional charging equipment and an approved electrical installation.
Can I charge an EV using rooftop solar?
Yes. A correctly designed solar and EV charging system can use rooftop solar electricity to charge an electric vehicle.
Can an EV battery replace a home battery?
Potentially for some energy-storage requirements, but EV batteries and permanent home batteries have different advantages. Many future homes may use both.
Can an electric car power my home during a blackout?
Some V2H-compatible systems can potentially supply backup power, but the vehicle, charger and electrical installation must specifically support this function.
What is a Home Energy Management System?
A Home Energy Management System, or HEMS, monitors and controls household energy equipment such as solar, batteries, EV chargers and major appliances to optimise when electricity is generated, stored and consumed.
Emerging Technology Series | EcoTech Homes
Exploring the technologies shaping smarter, lower-energy Australian homes.
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