Bi-directional charging is an exciting new development in the EV and battery storage space. Bidirectional charging is a feature that allows an electric vehicle (EV) to charge and discharge electricity in both directions. This means that the energy stored in an EV’s battery can be used to power a home or even fed back into the power grid.
What is Electric Vehicle Bi-Directional Charging (V2G, V2H, V2L, V2X)?
There are a few terms out there for what is essentially the same thing – bidirectional charging to/from your EV.
- Vehicle-to-grid (V2G) = energy flows from your EV to the electricity grid
- Vehicle-to-home (V2H) = energy flows from your EV to your house circuits
- Vehicle-to-load (V2L) = energy flows from your EV to anything that’s plugged into it (directly to an appliance, to a generator plug powering a house circuit, etc)
- Vehicle-to-everything (V2X) = all of the above
V2G – Why Use Vehicle-to-Grid?
V2G is most beneficial to the whole National Electricity Grid. Electricity providers can pay you to export the energy stored in your EV at times of high usage to reduce the need for fossil fuels. V2G can be used to help balance and settle local, regional, or national energy needs via smart charging.
V2H – Why Use Vehicle-to-Home?
Similar to V2G we can also use the same principle but use it to power our home! A benefit of V2H technology is avoiding being without electricity during a blackout, whether it lasts a couple of hours or a couple of days. V2H enables you to keep critical appliances running, it can also help to reduce energy costs.
As well as whole-home blackout proofing, the other main advantage is using your EV like a home battery – by charging the car up using renewable energy during the day, and then using that energy to power appliances at night. Using your EV’s battery in this way needs to be carefully managed so you don’t end up with no charge for your morning commute.
V2H has probably the most exciting potential for off-grid homes – with the future possibility of using the EV battery in conjunction with the off-grid system, as a backup power source before the fuel generator kicks in.
V2L – Why Use Vehicle-to-Load?
V2L can be used as a quick and simple way to manually blackout proof small individual appliances or a simple house circuit. Here’s some examples; Charging a laptop or a power tool, recharging another electric car, pulling over to boil a kettle and make a cup of coffee! The scenarios are plentiful for what V2L can assist with.
How Do I Set Up Bidirectional Charging?
Depending on whether you’re interested in V2G, V2H, or V2L – different equipment and requirements are needed.
V2X Setup Requirements
Firstly, for all scenarios you’ll need an EV with the bidirectional charging capability. Several EVs currently available in Australia have bidirectional capabilities. Brands that make EVs with bidirectional include Nissan, MG, BYD, Kia, Hyundai and Hyundai’s luxury brand Genesis. Mitsubishi plug-in hybrids (PHEVs) like the Outlander and Eclipse Cross also have bidirectional functionality. Volkswagen and Tesla are set to provide bidirectional options in the future also.
V2L Setup Requirements
This is the least complex option to set up. An electrician fits a generator inlet with a manual ‘changeover switch’ to your home, that isolates a chosen circuit (all the ‘essentials’ that you need backup power for). During a blackout an EV with V2L can be plugged into the generator inlet, with an adapter, to power that circuit. Note: the power supplied to your home is limited by the AC inverter in the EV. So this needs to be accounted for when running certain appliances.
V2H Setup Requirements
You’ll need an EV charger that’s capable of bidirectional charging, and a CT meter to monitor energy flows. Both of these will need to be installed by an electrician – preferably one who is experienced with solar & battery installations.
The new Australian Standards are expected to result in a wider range of lower priced bi-directional charges compatible with the more widely used CCS2 charging plug becoming available in Australia.
V2G Setup Requirements
In addition to the requirements for V2H, you’ll need the approval of your local Distributor for exporting the additional power into the electricity grid. Each Distributor will have their own approval process and individual requirements for your location and grid infrastructure, so it’s difficult to say what might be required in your circumstances. Enquiring with your local Distributor or EV Charger installer will be the best option to find out more.
At the time of writing, V2G chargers are only allowed in South Australia, and for specific applications in WA, NSW and the ACT.
