Subscribe & get the latest news in your email
blue x
Charging Technology

All You Need To Know About Bidirectional EV Charging


January 18, 2023

Electric vehicles (EVs) are rapidly transforming the transportation industry with a market value reaching $411 billion. While EVs offer several benefits as a greener and cheaper alternative to fuel and gas vehicles, they also pose certain challenges. A large obstacle of EV operations is the reliability of charging from the electric grid.

Bidirectional EV charging, also known as vehicle-to-grid (V2G) charging, provides a solution to this challenge by enabling EVs to not only charge from the grid but to send power back to it. This technology thus has the potential to completely revolutionize the way we use EVs.

What Is Bidirectional EV Charging?

Bidirectional EV charging is a connection between the electric grid and electric vehicle that allows energy to flow both ways. It allows electric vehicles to return power back to the grid when necessary in addition to the normal functionality of drawing power from it. This enables the vehicle to act as a distributed energy resource.

Bidirectional vs Traditional Charging

In traditional EV charging, there is a one-way power supply — the electric vehicle draws power from the grid. In bidirectional charging, the EV is equipped with an inverter that enables it to also discharge energy. This means that the EV can draw power and send power back to the energy grid.

This is extremely useful when there is a high demand for energy or when there is a shortage of power. It can also help balance the grid and reduce the necessity for peaker power plants.

Since bidirectional technology is still in its early stages of development, it’s uncommon and not all EVs are equipped with bidirectional charging capabilities.

How Is Bidirectional EV Charging Beneficial?

Bidirectional EV charging is extremely advantageous as it can be used in different ways:

  • Balancing the grid’s supply and demand by acting as a mobile device for storing energy. Once an EVs battery is fully charged, bidirectional inverters enable it to send power back to the grid. This helps balance the grid’s supply, making it more stable, particularly during periods of high demand.
  • Can offset the cost of charging. It can reduce the overall costs associated with EVs as the vehicle can send power back to the grid when not in use.
  • Can be used to avoid peak-hour surcharges. Utilities and electricity providers can use bidirectional charging to use EVs’ stored energy instead which can reduce electricity costs.
  • Makes renewable energy more efficient. Excess energy from renewable sources such as solar and wind can be stored in an EV’s battery and used through bidirectional charging. This can help reduce our dependence on fossil fuels since renewable energy becomes more efficient.
  • Provides a source for flexible energy distribution, making the power grid more stable and reliable. EVs can interact with a smart grid and provide grid services such as frequency regulation, voltage support, and peak shaving.

How Are Bidirectional and Smart Charging Different?

Bidirectional and smart charging are distinct but closely related concepts concerning electric vehicle charging.

Bidirectional charging refers to the ability of an EV to charge and discharge power from the electric grid by drawing and returning power to it. Essentially, it allows the EV to act as a distributed energy source with the help of an inverter.

In contrast, smart charging refers to the optimization of EV charging based on various factors such as grid conditions, charging during off-peak hours to avoid surcharge pricing, and the car battery’s state of charge (SOC). Smart charging systems minimize the cost of charging and reduce the impact on the grid by automatically adjusting the EV’s charging based on these factors.

Smart charging systems use advanced algorithms and communication technologies for a more optimized charging management system.

How Does Bidirectional EV Charging Work?

Bidirectional EV charging can seem like a complicated technology, but that isn’t necessarily the case.

The basic components of a bidirectional EV charging system include:

  • An EV equipped with a bidirectional charger and inverter that allows the vehicle to charge and discharge energy.
  • A charging station that can be connected to the EV and electric grid.
  • An effective energy management system that controls the flow of energy between EVs and the grid, allowing you to charge or discharge the batteries while monitoring the grid’s supply and demand.

Once the EV is connected to a bidirectional charging station, the energy management system checks the state of the grid. If the grid is experiencing high demand and short supply, the energy management system will discharge energy from the EV’s battery and direct it toward the grid to help balance supply and demand. If the grid has a surplus of energy, the system will charge the EV’s battery.

The energy management system will also take into account the EV’s charging schedule, electricity costs at different times of the day, and the EV battery’s state of charge. It will then optimize the charging process in a way that reduces charging costs and the load on the grid.

Is Bidirectional Charging Currently Implemented?

Bidirectional charging is a relatively new technology so we have yet to witness its large-scale implementation. However, there are promising initiatives that could encourage faster adoption:

  • e4Future, a V2G demonstration project in Denmark, launched in 2013 to test the economic and technical feasibility of using EVs as distributed energy storage sources. Involving over 100 Nissan LEAF EVs, it demonstrated how valuable V2G can be in reducing carbon emissions and balancing the grid.
  • A 2022 study by the National Health Service revealed that V2G can help reduce electricity costs by $90 a month and over $1,300 a year.
  • Meanwhile, a study conducted by the California Energy Commission established the feasibility of V2G technology as a revenue-generating enterprise. It also showed that the rate of degradation in electric car batteries is almost the same between traditional charging and V2G.
  • Late last year, Honda demonstrated how a fleet of its EVs could successfully balance the grid and maintain a continued state of charge for drivers. By showing its capabilities, Honda became the first car manufacturer in Europe to prequalify for certification of frequency containment reserve (FCR).

With all these developments, who knows? We may see widespread bidirectional EV charging sooner than we think.

Final Thoughts: The Role of Energy Management Systems In Bidirectional EV Charging

Bidirectional EV charging systems can be extremely helpful in optimizing EV charging, reducing costs, making renewable energy sources more efficient, and reducing the impact on the grid.

Ampcontrol’s energy management software is crucial for ensuring that you reap all the benefits that bidirectional EV charging offers. It is reliable, easy to use, and feature-rich. With it, you can accurately oversee and manage your charging stations in real time, take advantage of dynamic load sharing, optimize energy costs, and more.

Visit Ampcontrol’s website or request a demo to learn more.

Related Posts
See All Posts

Learn how fleet operators use Ampcontrol

Ampcontrol is a cloud-based software that seamlessly connects to charging networks, vehicles, fleet systems, and other software systems. No hardware needed, just a one-time integration.