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What is Bidirectional Charging And How EV Drivers Can Benefit?

bi-directional charging

During power safety shutoffs in California, millions of residents have been without power to mitigate the wildfire risk. Many electric vehicle (EV) drivers have been frustrated that they couldn’t use the electricity in their car batteries to power their homes or other critical loads. Despite having energy storage capabilities with their EV batteries, they could only access the electricity for powering their vehicle and not take advantage of bidirectional charging.

Increasingly, EV owners can power critical loads, either by purchasing a wall box unit or from the cars themselves. Bidirectional charging systems offer numerous benefits to households and even utility companies. Understanding what bidirectional chargers are and how it works is critical when potential solar customers have questions. Bidirectional charging is an excellent way to have emergency power during outages without relying on a

Bidirectional charging is a hot topic right now, and it is likely to grow in popularity as the capabilities of EVs expand over time. As a result, several automakers have announced they are releasing vehicles with bidirectional abilities, including Ford, Hyundai, Lucid, and Tesla.

What Is Bidirectional Charging?

As the name describes, bidirectional charging is EV charging that goes two ways: pulling power from the grid to charge the EV’s battery and supplying electricity for other loads from the battery as needed. An EV can help power a home, business, the utility grid, another vehicle, or specific loads by using bidirectional charging.

Currently, the Nissan Leaf has bidirectional charging abilities and requires installing a power supply center in the home to take advantage of this power for household use. The Ford 150 Lightning, can deliver 9.6 kW of power to a home for several days through the home’s electrical panel. This set-up requires Ford’s Charge Station Pro and a 100-amp circuit. The Hyundai Ioniq 5 and 6 can also power loads and supply 3.6 kW of electricity.

How Does Bidirectional Charging Work?

Alternating current (AC) power from the grid is converted to direct current (DC) voltage that is stored in the car’s battery while charging. Then, EV drivers can access the power in the battery to power a home or add power back to the electricity grid. For this to happen, the power is converted from DC to AC electricity. A converter in the vehicle or in the charger itself performs this function.

One such product is the Wallbox Quasar, a bidirectional DC charger for home use. It features a CHAdeMO or CCS Type 1 connector and includes an app with some energy management abilities.

What Are The Different Types Of Bidirectional Charging?

Bidirectional EV chargers can be used in different applications, depending on needs and capabilities.

Vehicle To Grid (V2G)

This involves vehicles communicating with the utility grid and supplying power as needed. Many people believe bidirectional charging will be a critical component of the power grid of the future and the increased use of renewable energy.

V2G capabilities enable charging EV batteries with renewable energy, such as wind and solar, when they are available. Then, the EV provides power to the grid from the batteries to supplement when not in use and help reduce greenhouse gas emissions.

Vehicle To Home (V2H)

With this approach, an electric car can provide power to a home or office through its electrical panel and is especially helpful during power outages. Also, households that pay time-of-use rates could save money by using power from their EV battery during times of peak energy demand and charging the battery when electricity rates are lower.

For a home to receive power from an EV with V2H capabilities, it needs a power control system connected to the home’s electrical distribution center. Then, the vehicle must be plugged into the charger to pull electricity.

Vehicle To Load (V2L)

Vehicles with V2L capabilities have a built-in DC to AC inverter plus a standard power outlet. It enables people to plug their loads into the outlet, using power from the battery. EVs with these capabilities include the Ford F150 Lightning, Rivian R1T, Hyundai Ioniq, Kia EV6, and Tesla Cybertruck.

Vehicle To Vehicle (V2V)

Unfortunately, EVs have a range limiting how far they can travel between charges. The capacity of the EV battery, efficiency of the vehicle, and outdoor temperature all impact the vehicle range. V2V charging is one way to help overcome range anxiety because this feature enables an EV to provide some power to another.

This is a feature many automakers are working on, but only the Ford F150 Lightning and Lucid Air have this capability.

What Are The Benefits Of Bidirectional Charging?

Being able to use the EV battery to power other things has many advantages, both to the EV driver and even utility companies. In fact, EVs could eventually become a key component in a decarbonized grid.

Potential Utility Bill Savings

If the local utility offers time-of-use rates, then electricity prices fluctuate during the day based on demand. Typically, energy prices are highest on weekday afternoons and early evenings in the summer and lowest in the middle of the night. Thus, providing power during peak demand and then either charging with solar panels or from the grid during off-peak times saves money.

Backup Power During Blackouts

A couple of widespread power outages have occurred in the last year or two, including the 2021 Texas Power Crisis and California public safety power shutoffs that left millions without power. EVs with V2H capabilities can power an entire home during a utility outage. The battery capacity and its level of charge determine how many loads and how long an EV can power a home.

Power Beyond The Grid

V2L capabilities enable EVs to power specific loads by plugging into an outlet. This option can be very beneficial when camping or in an area where utility power isn’t available. For example, tradespeople can power tools on job sites.

What Are The Disadvantages of Bidirectional EV Chargers?

While bidirectional charging has several advantages, it also has some disadvantages. However, ongoing research can help overcome these challenges.

  • EV Battery Degradation:

  • Frequent charge and discharge cycles associated with bidirectional charging can contribute to faster battery degradation, reducing the overall lifespan of electric vehicle batteries.

  • Cost and Complexity:

  • Implementing bidirectional charging requires specialized infrastructure and equipment, adding complexity and cost to both the charging station and the electric vehicle.

  • Limited Vehicle Compatibility:

  • Not all electric vehicles are currently equipped for bidirectional charging. This limitation reduces the widespread adoption of this technology, as it depends on compatible electric vehicle models.

  • Grid Stability Concerns:

  • Bidirectional charging introduces additional variability to the electric grid, as vehicles may draw or return power unexpectedly. This can pose challenges for grid operators in maintaining stability and reliability.

  • Regulatory and Standardization Issues:

  • A lack of standardized protocols and regulations for bidirectional charging can hinder interoperability between different charging stations and electric vehicles, slowing down its widespread adoption.

  • Energy Losses:

  • The process of converting and transferring energy between the electric vehicle and the grid incurs some energy losses. This reduces the overall efficiency of bidirectional charging compared to unidirectional charging.

What Electric Cars Have Bi-directional Charging Capabilities?

Only a small handful of EVs on the US market have bidirectional charging features, with vehicle-to-grid being the most widespread. These vehicles with bidirectional charging are:

  • Ford F-150 Lightning (V2G, V2H, V2V)

  • Genesis GV60 (V2L)

  • Hyundai Ioniq 5 (V2L) 

  • Hyundai Ioniq 6 (V2L) 

  • Kia EV6 (V2L) 

  • Kia Niro (V2L) 

  • Lucid Air (V2V)

  • Mitsubishi Outlander PHEV (V2L) 

  • Nissan Leaf (V2H, V2G)

  • Tesla Cybertruck (V2L)

  • VW ID.4 (V2H)

FAQs About Bi-directional Charging

Read on to learn answers to some of the most common questions about 2 way charging for EVs.

How does bi-directional charging benefit EV drivers?

Bidirectional charging empowers electric vehicle owners by turning their vehicles into flexible energy resources. Beyond traditional charging, this technology allows owners to sell excess energy back to the grid, providing potential revenue. Additionally, in emergencies, bidirectional charging enables electric vehicles to serve as temporary power sources for homes or other EVs.

Do all electric cars have bi-directional EV chargers?

No, not all electric vehicles are currently equipped for bidirectional charging. Compatibility depends on the vehicle's design and whether it supports the necessary hardware and software for two-way energy flow.

What issues does bi-directional charging create for EV batteries?

Bidirectional charging can contribute to faster battery degradation due to the increased frequency of charge and discharge cycles, potentially reducing the overall lifespan of electric vehicle batteries. However, battery degradation is minor and will only have a significant impact on the lifespan of an EV battery from heavy, repeated use.

Can bi-directional EV chargers eliminate the need for solar batteries?

While bidirectional charging provides a mechanism for electric vehicles to store excess power for use in homes, it doesn't entirely eliminate the need for solar batteries. Bidirectional charging primarily relies on the vehicle's battery, which may not have the capacity for extensive energy storage. Solar batteries, designed for stationary use, offer larger storage capacities and are better suited to store energy from solar panels for a consistent and reliable power supply. Also, EV drivers may be hesitant to completely discharge their EV batteries during power outages because it could limit their mobility.

What is true of bidirectional charging?

Unlike conventional EV charging systems, where energy flows from a power source to the vehicle's battery, bidirectional EV chargers allow power to flow in two directions. It allows electric vehicles to not only receive energy but also send it back, enabling the vehicle to share power with other devices or even the utility grid.

Bi-directional Charging Can Change the Clean Energy Industry

Bidirectional charging could create a transformative shift in energy usage, enabling electric vehicles to contribute excess energy to the grid, other vehicles, or homes. This dynamic interaction between electric vehicles and the energy ecosystem offers a decentralized approach, allowing for more efficient grid management, increased resilience during outages, and the potential to harness electric vehicles as distributed energy resources, shaping a more sustainable and adaptable energy future.

The GreenLancer marketplace is available for electric vehicle charging contractors. We offer EV charging station design and engineering services nationally to accelerate EV adoption. Learn more about GreenLancer EV, our marketplace where contractors can shop on-demand EV charging station design and engineering services.


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