Vehicle To-Grid Solutions For Electric Vehicles
What is V2G and V2X?
V2G stands for “vehicle-to-grid” and is a technology that enables energy to be pushed back to the power grid from the battery of an electric car. With vehicle-to-grid technology, a car battery can be charged and discharged based on different signals — such as energy production or consumption nearby.
V2X means vehicle-to-everything. It includes many different use cases such as vehicle-to-home (V2H), vehicle-to-building (V2B) and vehicle-to-grid. Depending whether you want to use electricity from EV battery to your home or building electrical loads, there are different abbreviations for each of these user cases. Your vehicle can work for you, even when feeding back to grid would not be the case for you.
In a nutshell, the idea behind vehicle-to-grid is similar to regular smart charging. Smart charging, also known as V1G charging, enables us to control the charging of electric cars in a way that allows the charging power to be increased and decreased when needed. Vehicle-to-grid goes one step further, and enables the charged power to also be momentarily pushed back to the grid from car batteries to balance variations in energy production and consumption.
2. Why should you care about V2G?
Long story short, vehicle-to-grid helps mitigate climate change by allowing our energy system to balance more and more renewable energy. However, to succeed in tackling the climate crisis, three things need to happen in the energy and mobility sectors: Decarbonisation, energy efficiency, and electrification.
In the context of energy production, decarbonisation refers to the deployment of renewable energy sources, such as solar and wind power. This introduces the problem of storing energy. While fossil fuels can be seen as a form of energy storage as they release energy when burned, wind and solar power function differently. Energy should be either used where it’s produced or stored somewhere for later usage. Therefore, the growth of renewables inevitably makes our energy system more volatile, requiring new ways to balance and store energy to be used.
Simultaneously, the transportation sector is doing its fair share of carbon reduction and as notable proof of that, the number of electric vehicles is increasing steadily. Electric vehicle batteries are by far the most cost-efficient form of energy storage, since they require no additional investments on hardware.
Compared to the unidirectional smart charging, with V2G the battery capacity can be utilized more efficiently. V2X turns EV charging from demand response to battery solution. It enables to use the battery 10x more efficiently compared to unidirectional smart charging.
vehicle-to-grid solutions
Stationary energy storages — big power banks in a sense — are becoming more common. They are a handy way of storing energy from, for instance, large solar power plants. For example, Tesla and Nissan offer home batteries also for consumers. These home batteries, together with solar panels and home EV charging stations, are a great way to balance out energy production and consumption in detached houses or small communities. Currently, one of the most common forms of storage are pump stations, where water is pumped up and down to store energy.
On a larger scale, and compared to electric vehicles, these energy storages are more expensive to supply and require significant investments. As the number of EVs is continuously rising, electric cars provide a storage option with no extra costs.
At Virta, we believe that electric cars are simply the smartest way to help with renewable energy production, as EVs will be part of our lives in the future — regardless of the ways we choose to use them.
3. How does vehicle-to-grid work?
When it comes to using V2G in practice, the most important thing is to make sure that EV drivers have enough energy in their car batteries when they need it. When they’re leaving for work in the morning, the car battery must be full enough to drive them to work and back if needed. This is the basic requirement of V2G and any other charging technology: The EV driver must be able to communicate when they want to unplug the car and how full the battery should be at that time.
When installing a charging device, step number one is to review the electrical system of the building. The electrical connection can become a hindrance to the EV charging installation project or increase costs significantly in case the connection needs to be upgraded.
Vehicle-to-grid, as well as other smart energy management features, helps enable electric vehicle charging anywhere, regardless of the surroundings, location, or premise. The benefits of V2G for buildings are visible when the electricity from car batteries is used where it is needed the most (as described in the previous chapter). Vehicle-to-grid helps balance out electricity demand and avoid any unnecessary costs for building an electricity system. With V2G, the momentary electricity consumption spikes in the building can be balanced with the help of electric cars and no extra energy needs to be consumed from the grid.
For the power grid
Buildings’ ability to balance their electricity demand with V2G charging stations also helps out the power grid on a larger scale. This will come in handy when the amount of renewable energy in the grid, produced with wind and solar, increases. Without vehicle-to-grid technology, energy has to be bought from reserve power plants, which increases electricity prices during peak hours, since striking up these extra power plants is a pricey procedure. Without control you need to accept this given price but with V2G you are master to optimize your costs and profits. In other words, V2G enables energy companies to play ping pong with electricity in the grid.
For consumers
Why would consumers take part in vehicle-to-grid as a demand response then? As we explained earlier, it does no harm to them, but does it any good either?
Since vehicle-to-grid solutions are expected to become a financially beneficial feature for energy companies, they have a clear incentive to encourage consumers to take part. After all, the technology, devices, and vehicles compatible with the V2G technology are not enough – consumers need to take part, plug in and enable their car batteries to be used for V2G. We can expect that in the future on a larger scale, consumers are being rewarded if they are willing to enable their car batteries to be used as balancing elements.
4. How will vehicle-to-grid become mainstream?
V2G solutions are ready to hit the market and start doing their magic. Yet, some hurdles need to be overcome before V2G becomes the mainstream energy management tool.
A. V2G technology and devices
Multiple hardware providers have developed device models compatible with vehicle-to-grid technology. Just like any other charging devices, V2G chargers already come in many shapes and sizes.
Usually, the maximum charging power is around 10 kW — just enough for home or workplace charging. In the future, even wider charging solutions will apply. Vehicle-to-grid charging devices are DC chargers, since this way the cars’ own unidirectional on-board chargers can be bypassed. There have been also projects where a vehicle have an onboard DC charger and the vehicle can be plugged to an AC charger. However, this is not a common solution today.
To wrap up, devices exist and are feasible, yet there’s still room for improvement as the technology matures.
V2G compatible vehicles
Currently, CHAdeMo vehicles (such as Nissan) has outpaced other car manufacturers by bringing V2G compatible car models to the market. All Nissan Leafs on the market can be discharged with vehicle-to-grid stations. The ability to support V2G is a real thing for vehicles and many other manufacturers will hopefully join the club of vehicle-to-grid compatibles soon. For instance, Mitsubishi has also announced plans to commercialize V2G with Outlander PHEV.
Does V2G affect car battery life?
As a side note: Some V2G opponents claim that using vehicle-to-grid technology makes the car batteries less long-lasting. The claim itself is a bit strange, as car batteries are being drained daily anyways – as the car is used, the battery is discharged so we can drive around. Many think that V2X/V2G would mean full power charging and discharging, i.e. the battery would go from zero percent state of charge to 100% state of charge and again to zero. This is not the case. All in all, vehicle-to-grid discharging doesn’t affect the battery life, as it only happens for a few minutes a day. However, EV battery lifecycle and the impact of V2G on it are studied constantly.
Does V2G affect car battery life?
As a side note: Some V2G opponents claim that using vehicle-to-grid technology makes the car batteries less long-lasting. The claim itself is a bit strange, as car batteries are being drained daily anyways – as the car is used, the battery is discharged so we can drive around. Many think that V2X/V2G would mean full power charging and discharging, i.e. the battery would go from zero percent state of charge to 100% state of charge and again to zero.