The energy transition has become a major challenge in current public policies. Its application to mobility through the electric vehicle leads to the emergence of new concepts at the crossroads of the automobile, electrical networks, renewable energies and buildings.

In this article, we present to you the concept of vehicle-to-grid: what is it for? How does that work? And what are the advantages, especially for businesses.

What does Vehicle-to-Grid (V2G) mean?

Some definitions

In English, “vehicle-to-grid” (V2G) means from the vehicle to the electrical network : it is a technology that allows the energy stored in the battery to be transferred to the electrical network.

Many concepts have been developed around the electric vehicle, the V2G is just one example among others:

• V1G (unidirectional smart charging) : it is simply the recharging of a vehicle battery; the concept of intelligence concerns only the dynamic management, by the electric vehicle, of charging rates and times via a data connection, in order to minimize the cost of charging.
• V2B/V2H (Vehicle to Building/Vehicle to Home) : similar technologies that make it possible to manage the bidirectional charge of an electric vehicle in order to locally optimize the renewable energies produced, for example a photovoltaic installation installed on the roof of a building will charge the vehicle battery, and, in case of absence of PV production, supply energy to the building via the vehicle battery.
• V2I (Vehicle-to-Infrastructure) : to refer to the exchanges of data between a electric car and road units, such as equipment installed along roads to exchange information on traffic conditions and emergency information to vehicles and their drivers.
• V2V (Vehicle-to-Vehicle) : for the transfer of data directly between vehicles located in close proximity to each other, whether a few hundred meters further forward or hidden behind an obstacle such as a truck or a building, like the proximity sensors embedded in a vehicle today.
• V2X (Vehicle-to-Everything) : to refer to the transmission of information between a vehicle and another object (vehicle, charging station, road infrastructure, etc.) interacting with it.

Source: CentraleSupélec

Here, we will focus in particular on everything related to technologies related to energy transfer.

What is the point in practice?

The idea of vehicle-to-grid is to use batteries parked electric cars like storage capacity to participate in The balance of the network. Like stationary batteries, these batteries can store electricity when the production fed into the grid exceeds the demand, and, on the contrary, supply energy to the grid when consumers draw more than the power plants can produce.

This technology makes it possible to exploit the charging and discharging of electric vehicle batteries to support the electrical network when they are connected to it.

Source: RossiniEnergy

By contributing to the balance of the network, V2G will contribute more and more to the integration of intermittent renewable energies.

How does Vehicle-to-Grid (V2G) work?

Support for smart technologies

The main function of batteries in an electric vehicle is to store energy to power its propulsion. The V2G must therefore take into account the future use of the car.

To do this, its battery must be sufficiently charged so that its autonomy can allow future trips.

V2G is closely linked to another concept, that of smart charging, which is based on the use of smart meters And of smart charging stations capable of automating and optimizing priority management.

Automating the charging of electric vehicles also requires the implementation of regulations to ensure interoperability between vehicles and infrastructures, such as Charging stations. That's where the vehicle-to-everything (V2X), so that standardized messages can be interpreted by all stakeholders. Communication security is based in particular on PKI architectures allowing various objects (car, charging station, etc.) to exchange certificates to identify themselves.

Smart charging

Intelligent vehicle charging is based on the principle that a data communication is established between the vehicle and the charging station to which it is connected.

If this charging station is part of a Smart grid, the battery charge can be optimized according to the prices per kWh, the needs of the electrical network, peak demand, intermittent renewable productions, etc.

These technologies are beneficial for the electrical network, which can control the charging of the batteries at the best time, and for the consumer, who will pay less to recharge their vehicle.

A company that has a fleet of vehicles has every interest in installing communicating and adapted charging stations on its sites. The way in which company vehicles are used is often very closely linked to the company's activity. The charge and discharge cycle is predictable; vehicles are often parked in company car parks in the evenings and weekends, or even for part of the day.

Therefore, thanks to technologies such as V2G, it is possible to make these batteries profitable during downtime by making battery storage capacity available at the service of the network. The V2G can be combined with fleet management tools so that vehicle load management can be constantly adapted to the daily needs of the company's activity.

Source: PV-Magazine

What are the advantages of Vehicle-to-Grid (V2G)?

Vehicle-to-grid (V2G) is an innovative technology at the heart of an ecosystem rich in actors and complex in interaction, which makes it possible to accelerate the development of the electric vehicle.

This technology offers numerous opportunities for companies using these vehicles, fleet managers, car manufacturers, electricity suppliers, electrical networks, capacity aggregators, the managers of charging station infrastructures, the manufacturers of these terminals, etc.

The Vehicle-to-Grid allows:

• to increase the value of an electric vehicle by making the most of its battery;
• to reduce the total cost of an electric vehicle fleet;
• to bring flexibility to the electrical network;
• to promote the integration of intermittent renewable energies;
• to optimize the portfolio of electricity suppliers;
• to increase the value of investments in charging stations.

Let's take a closer look at the benefits for the electrical network, real estate buildings and users.

The advantages for the electrical network

One of the main missions of transmission system operator (RTE) Is to ensure the balance between supply and demand. With V2G, the electrical network will be able to rely more and more on storage capacities distributed throughout the country, which will make it possible to:

• store electricity when electricity is plentiful and cheap;
• injecting electricity into the network during peak consumption, which will make it possible to avoid the use of advanced oil or gas power plants.

For the electrical network, this balancing energy has other interesting characteristics:

• The electricity injected by the batteries will have been produced with fewer CO emissions₂ and at a lower cost if, during charging, intermittent renewable energy productions have been maximized;
• the injection points will be very distributed and as close as possible to consumers, effectively limiting flows on major networks at times of extreme demand tension.

The advantages for real estate constructions

To take advantage of all the advantages of V2G technologies in real estate constructions, they must be equipped with communicating charging stations directly connected to the building's electrical installations.

Thus, these charging stations located in or on car parks will be particularly interesting during peak consumption, the energy stored in the batteries of parked vehicles coming directly to power the building in the event of congestion on the electrical network.

For corporate buildings and large shopping centers, this is all the more true as their attendance is directly proportional to the number of vehicles parked.

The V2G therefore allows real estate constructions to increase their security of supply, or even, if they are equipped with photovoltaic panels, to approach the concept of autonomous building.

The advantages for users

All the advantages listed above depend entirely on the acceptance of users. Users who connect their electric vehicles to the grid and accept V2G are needed for this technology and all the infrastructures deployed to be of economic interest for all stakeholders.

Two conditions are necessary for this. First of all, the user must be able to use their vehicle without fear of running out of battery while traveling. Second, the financial incentive must be attractive enough to motivate users to lend their vehicle batteries.

It is therefore a subtle balance between constraints and benefits that must be offered to users. This includes the ability to plan the use of an electric vehicle every day: schedules and durations of trips.

For this, the user will certainly be called upon to declare their future use before leaving the vehicle or using their smartphone; and the recording of known information on the past use and condition of the vehicle will be decisive in optimizing the use of the battery in V2G connected mode and generating financial income for the user.

What is the future for vehicle-to-grid (V2G)?

V2G in the office: a real opportunity for businesses?

First of all, you should know that a Obligation to green vehicle fleets weighs on businesses. Indeed, the Environmental Code sets out obligations concerning the share of low-emission vehicles (VFE) in public procurement during the annual renewal of vehicle fleets.

For private companies, this obligation is increasing: at least 10% from 2022, then 20% in 2024, 40% in 2027, and finally 70% in 2030.

It should also be noted that the 2019 Mobility Orientation Act sets out, among other things, obligations concerning the installation of charging stations. In non-residential buildings, the obligation is to have at least 20% of equipped spaces.

Source: data.gouv.fr

Finally, the Climate and Resilience Law, promulgated and published in the Official Journal on August 24, 2021, requires the installation of photovoltaic panels in commercial areas, car parks of more than 500 m² and office buildings of more than 1,000 m².

It is therefore entirely appropriate for companies to associate V2G technologies with the management of their electric vehicle fleet in order to promote, for the benefit of the balance of the network, the batteries of electric vehicles parked in their car parks.

Businesses can thus take part in the energy transition by offering an additional service to their customers and employees using an electric vehicle.

Vehicle-to-grid is a rapidly expanding technology that goes hand in hand with the development of electric vehicles and charging stations by extension.

It should be noted with interest that manufacturers are testing vehicle-to-grid (V2G). Renault, for example, is experimenting on the small island of Porto Santo with an ecosystem combining electricity and smart charging systems. Analysts believe that the switch to electromobility will lead to 15 to 20% increase in electricity consumption.

We therefore understand the risks and opportunities that the electric vehicle inherently carries: risks associated with the significant increase in electrical consumption in a context of both energy sobriety and energy transition to clean energies; and opportunities to valorize the batteries of parked vehicles on the electrical network to support the growth of electricity needs and the development of intermittent renewable energies such as wind power or photovoltaic energy.

The vehicle-to-grid is therefore becoming a major industrial challenge for car manufacturers, network operators and businesses.

It is obvious that all actors must agree on technical and commercial standards so that a vehicle can connect to any station to recharge and/or participate in the balance of electrical networks, like industrial tools that contribute in their own way to the balance of the network by stopping consumption during peak consumption.

Did you know that?

Today, more than ever, electric mobility is one of the levers for achieving carbon neutrality. As such, businesses have a role to play in the energy transition.
You want to install charging stations and/or convert your company's vehicle fleet to electric? SirEnergies is there to help you and supports you in building an eco-responsible image for your business.
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