Hate big power bills? Interested in a home battery but can’t justify the cost? Vehicle to grid technology is about to offer solutions to both problems.

Vehicle to grid, or ‘V2G’ as manufacturers use for shorthand, is a technology which lets you use an electric car battery to power your home (sometimes called V2H or vehicle to home) or sell energy back into the power grid.

Some cars, particularly the Nissan Leaf and Mitsubishi Outlander, have technically been capable of supporting this two-way-charging tech for some time, but there haven’t been regulation-supported standards in place.

Federal Climate and Energy Minister Chris Bowen made an announcement at Sydney’s International EV Autoshow that Standards Australia has signed off on a new protocol, allowing the technology to be approved for use in Australia.

Now, car manufacturers will be able to have their bi-directional technologies tested to the new standard, and apply to have their devices listed by the Clean Energy Concil as approved V2G products in Australia.

This will allow said devices to interface with distribution networks and allow a vehicle to feed energy to the grid or home. Approval for mainstream use of V2G tech is expected before the end of the year.

In theory, this new development allows some electric vehicle owners to bypass the need for a home battery system and power their home directly from the car’s battery. While most home battery systems currently are in the order of 10 – 15kWh, a car battery is generally over 40kWh, allowing a significant amount of energy to be utilised for home or grid power, where previously it could only be used for transport.

As an example, this could allow an electric vehicle owner to charge their vehicle using solar during the day, then sell excess energy not needed for driving at peak times during the night. Alternatively, the car could buy cheap energy from the grid and store it in its battery overnight, then sell it back to the grid at a higher rate during peak times in the morning or afternoon.

However, it is worth noting that in most cases, EV owners will need to invest in a home charger and smart metre which is capable of supporting V2G protocols and required software.

Not only will V2G and V2H capability help the government meet its emissions targets, but it will also improve grid stability and make better utilisation of energy resources in the grid, by providing a way for idle energy to be stored en masse and used in times of shortage.

However, few electric vehicles in Australia are currently capable of supporting vehicle-to-grid. For example, the popular Tesla Model 3 and Tesla Model Y, which make up the vast majority of electric vehicles which have sold in recent years, do not support the technology, and for many manufacturers, V2G has either not been made available, or isn’t available in Australian-delivered vehicles.

Hyundai, Kia, BMW, Ford, Honda, Toyota and Volkswagen have all announced their intention to invest in V2G support in their vehicles going forward, some of which already support the tech in markets overseas.

In the meantime, Nissan Leaf, Mitsubishi Outlander and Eclipse Cross owners will be the first to take advantage of this new development, as all three vehicles were used as part of a trial of the technology in the South Australian energy grid in 2022 thanks to their Japanese-standard CHAdeMO connectors, which have supported V2G since they were released. At the time, the trial required a circa $10,000 vehicle-to-grid supporting inverter to allow energy from the car to be sold back into the grid.