As the number of electric vehicles (EVs) on our roads continue to grow, so does the need for innovative and efficient charging solutions. Among these innovations, bi-directional charging emerges as a promising technology that may revolutionise the way we charge our EVs. In this comprehensive guide, we discuss bi-directional charging, its benefits, and how it can be utilised for various purposes, including vehicle-to-grid (V2G), vehicle-to-home (V2H), and vehicle-to-load (V2L). Furthermore, we cover UK bi-directional regulations, the current list of bi-directional cars and chargers available, and finally, its potential impact on the future of EVs.
What is Bi-directional Charging?
Bi-directional charging is a technology that enables electric vehicles to not only draw power from the electric grid but also return that power back to the grid or use it for other purposes. This two-way flow of energy increases the overall efficiency and utility of EVs, as they can act as energy storage devices outside their primary purpose of transport.
How does it work?
Bi-directional chargers use a type of inverter with the unique ability to convert electrical energy in both directions: from alternating current (AC) to direct current (DC) and vice versa. This allows energy stored in an EV’s battery to be fed back into the grid, a connected home, or another device, depending on the energy needs at the time.
When an EV is plugged into a bi-directional charger, the charger can either send current from the grid to the vehicle’s battery, or turn the excess stored energy in the EV back into AC and feed it back to the grid, when needed. This process is managed and controlled by the vehicle’s onboard Energy Management System (EMS) and the bi-directional charger’s respective controls.
What are the benefits?
Bi-directional charging offers a variety of benefits that enhance the way we utilise an electric vehicle’s battery. Some key advantages include:
- Energy efficiency: Bi-directional chargers can help to reduce peak demand on the power grid. By drawing energy stored in EV batteries during peak demand or transferring it back during off-peak hours, it helps maintain a more balanced and efficient grid system.
- Cost savings: If you own an EV, bi-directional charging allows you to take advantage of electricity price fluctuations, by charging your vehicle when energy prices are low and potentially selling energy back to the grid when prices are high, leading to financial savings in your energy bills.
- Backup power supply: In case of a power outage or an emergency, an EV with bi-directional charging capability can act as a backup power supply for your home, keeping the lights on and your essential appliances running.
Vehicle to Grid (V2G), Vehicle to Home (V2H), and Vehicle to Load (V2L) explained
Vehicle to Grid (V2G)
V2G is a system in which electric vehicles with bi-directional charging capabilities can provide power back to the grid, helping to balance the power supply and demand, particularly during peak hours. Integrating V2G technology can improve grid stability, optimise renewable energy integration, and generate added revenue for EV owners.
Vehicle to Home (V2H)
V2H is a system where an EV serves as a temporary energy storage device for a connected home, providing power when necessary. This system can be used in the event of a power outage or if energy prices are high, allowing homeowners to save money on utility bills.
Vehicle to Load (V2L)
V2L is a technology that enables an EV battery to supply electricity directly to devices other than the grid or a connected home. This type of technology is particularly useful for remote areas where it is difficult to access grid power, allowing EV owners to provide electricity to crucial devices such as medical equipment or communication systems. V2L can be performed without the need for a bi-directional charger.
Bi-directional charging and solar panels
Bi-directional charging can be coupled with solar panels, allowing for a more efficient and cost-effective energy usage. By installing solar panels, EV owners can produce their own green electricity to charge the vehicle or feed surplus energy back into the grid. This system is particularly beneficial in areas where access to grid power may be limited due to geographical restrictions.
UK Bidirectional charging regulations
Despite the attention it has received, one of the challenges faced by V2G technology implementation is the lack of standardised bidirectional charging protocols and connectors, along with regulatory hurdles. Bidirectional chargers, similar to solar inverters, are considered an additional power generation source and must comply with safety and shutdown standards in case of grid failures. To address these complexities, certain vehicle manufacturers, like Ford, have developed simplified AC bidirectional charging systems that exclusively function with their EVs, providing power to homes instead of exporting to the grid. Other manufacturers, such as Nissan, utilise universal bidirectional chargers, like the Wallbox Quasar
That being said, this technology shows huge potential to alleviate some of the ever-increasing demand on the power grid and, as such, is likely to see massive advancements in the coming years. With more and more households adopting electric vehicles in 2023, we could soon live in a world where tens of thousands of electric vehicles simultaneously supply power back to the grid at times of high demand.
Current Bi-directional Cars and Chargers available in 2023
Not all electric vehicles have bi-directional charging capabilities, and neither do the chargers.
As we’ve mentioned, this is very much a fast-moving area of EV technology so expect this list to grow exponentially in a short space of time. However, as it stands in 2023, these are the cars and chargers that have bi-directional offerings.
Electric vehicles with bi-directional charging capabilities 2023
| Model | V2G | V2H | V2L |
| Hyundai Ioniq 5 | No | No | Yes |
| Nissan Leaf ZE1 | Yes | Yes | No |
| MG ZS EV (2022 model) | No | No | Yes |
| Kia EV6 | No | No | Yes |
| BYD Atto | No | No | Yes |
| Ford F-150 Lightning (only compatible with Ford Charge Station Pro) | Yes | Yes | Yes |
| Outlander PHEV | Yes | Yes | No |
Bi-directional Electric Chargers 2023
At the time of writing, there is quite a limited amount of EV chargers available that offer bi-directional charging. However, there are many that are currently still in development with a scheduled release for late 2023.
Wallbox Quasar
The Wallbox Quasar is a groundbreaking bidirectional EV charger specifically designed for residential use with a maximum power rating of 7.4kW (32A). It stands out as the most compact charger in its category, offering advanced two-way DC charging capabilities.
It is important to mention that this charger is exclusively compatible with vehicles equipped with a CHAdeMO DC vehicle connector.
Wallbox are currently developing the Quaser 2 which will offer a more powerful 11.5kW (48A) charge and discharge rate, WiFi, Ethernet and Bluetooth connectivity options and compatibility with the more prominent CCS1 DC charging port.
Fermata FE-15
The FE-15 bidirectional charger (presently exclusive to North America) is the dominant two-way DC charger when it comes to power with an impressive 15kW charge and discharge power rating. From its sleek design to its robust specifications, the wall-mounted charger exemplifies a commitment to performance, longevity, and safety. Just like the Wallbox Quaser, this charger can only be used with electric vehicles that have a CHAdeMO DC connection type.
Rectifier Technologies Highbury
The upcoming Highbury bidirectional DC charger is poised to revolutionise the charging industry with its advanced features. With an impressive efficiency rating of 96%, this charger combines sleek and contemporary design with functionality. It stands as the world’s thinnest bi-directional DC charger, offering two models: the standard 7kW and the high-power 11kW (46A).
Beyond enabling electric vehicle (EV) owners to sell surplus power to the grid through vehicle-to-grid (V2G) technology, the Highbury charger has plans for future enhancements. It aims to introduce vehicle-to-home (V2H) functionality, expanding its capabilities further. Additionally, this charger ensures widespread usability by being compatible with both CHAdeMO and CCS compliant EVs.
Bi-directional charges set for a 2023 release
These upcoming chargers also offer impressive functionality and specifications, and are scheduled to be available to the public later in the year.
- Emporia V2X
- Delta V2H
- Ford Charge Station Pro
- Autel Maxicharger V2X
- SolarEdge bidirectional EV charger
Keep an eye out for these, as they will all be available soon!
Potential impact on the future of EVs
Bi-directional charging could potentially have a significant impact on the future of electric vehicles, as it unlocks many opportunities for EV owners and opens up new revenue streams. As bi-directional chargers become more widely available and government incentives increase, it will make EVs even more attractive to consumers, leading to greater adoption and accelerating the transition to electric transportation.
Not only will this help reduce carbon emissions, but consumers could also potentially pay less for their electricity bills as they return unexpended energy back to the grid; this combined with renewable energy sources such as solar power could see a major shift away from the status quo when it comes to powering our homes.
Additionally, with more automakers investing in V2G and V2H technology, it is likely that we will see significant advancements in bi-directional charging capabilities, opening up even more possibilities and applications. For example, bi-directional chargers could be used to provide electricity to remote areas where access to grid power is scarce or non-existent, allowing for greater energy independence in these regions.
In summary, the potential of bi-directional EV charging stands to revolutionise the way we use energy and could help reduce the reliance on fossil fuels, paving the way for a greener, cleaner future.
This technology is still in its infancy but certainly has exciting potential to reshape the way we use energy – and it’s only going to get bigger! As more automakers invest in research and development, bi-directional chargers are likely to become more widely available and could soon be a common feature of electric vehicles. The possibilities for bi-directional charging are seemingly endless – watch this space!
