The growth of electric vehicles and the smart grid has led to the creation of Vehicle-to-Grid (V2G) technology. Imagine using your electric vehicle to power your home during a storm-induced power outage. While your vehicle may not be able to power your entire house, there likely would be enough energy to charge your phone, power the lights, and keep your refrigerator on. How is this possible? Through the use of V2G technology.
The meaning of Vehicle-to-Grid (V2G) technology
Vehicle-to-Grid technology involves drawing unused power from the car into the smart grid. V2G, which is also known as vehicle-grid integration (VGI), can help the energy grid supply electricity during peak hours. It can also create an extra power source when weather-dependent renewable energy sources are not available. For example, a home that uses solar power cannot generate electricity at night, but an electric vehicle could provide a secondary source of power if needed.
Vehicle-to-Grid technology includes many different use cases such as vehicle-to-home (V2H), vehicle-to-building (V2B), and Vehicle-to-Grid itself. Depending on whether you want to use electricity from an EV battery to your home or building electrical loads, there are different abbreviations for each of these use cases. Your vehicle can work for you, even when feeding back to the power 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 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 immediately pushed back to the power grid from car batteries to balance variations in energy production and consumption.
Vehicle-to-Grid technology is considered a real game-changer in the electric vehicle space, because this two-way transfer not only encourages a more active way of consuming energy, it could open up new income streams for drivers, fleet operators, and even vehicle manufacturers.
How does the V2G technology work?
V2G charging refers to the 2-way flow of electrical energy from the grid, through a specially-built charger into an EV, and back again. As an EV owner, you can choose to charge your car up from the grid – or sell stored energy in your car back to the grid. Most people are only using a fraction of their battery capacity, and that means there’s a huge amount of spare, stored energy that could be providing services elsewhere. Services such as supporting local energy distribution utilities, or mitigating the intermittency of renewable energy. And imagine if you could make money from these services when your car is just doing nothing at home?
Initially, Vehicle to Grid is actually Grid to Vehicle, as the car takes energy from the National Grid to charge up. When the battery is full, an inverter is able to move energy from the car, back to the grid, when there is demand and when the owner is willing. You can set limits on how much charge can be withdrawn, to ensure you’re never left with an empty battery.
The key benefits of Vehicle-to-Grid?
One of the biggest frontiers in electrical engineering today is the development and implementation of smart grid technology. Fueled by the global demand for greener technologies and alternative fuels, environmentally-friendly smart grid technology has the ability to stimulate stagnant economies as well as change the way power is delivered to electricity consumers around the world.
There are peak times and off-peak times for energy use, just like there’s rush hour traffic in the morning and in the evening.
Balancing the grid is about making sure there’s enough electricity on the network when we need it in peak times, so the country doesn’t blackout. And it also stops power surges, which could damage domestic appliances, or cause electrical fires.
In order to reduce the impact of climate change, each country is shifting its energy mix in favor of more renewables, which creates volatility.
Regardless of whether the wind is blowing or the sun is shining, the grid needs to remain balanced, and without Vehicle-to-Grid, energy has to be bought from reserve power plants, which means more pollution and increased energy prices during peak hours. But if the energy from millions of car batteries can be aggregated and managed to work alongside the electrical grid, it won’t need to rely on more central power plants to fix any constraint issues. It’s actually estimated that there’ll be around 140-240 million EVs on the road globally by 20301. So that’s up to 240 million batteries on wheels, ready to balance the grid when we need it. This type of technology can help meet clean energy goals such as targeting zero-carbon emission by 2045. It can also provide an added benefit to consumers by potentially lowering electric vehicle total cost of ownership. An owner can sell back surplus power from their vehicle in order to offset other costs.
V2G is a game-changer as we move towards an intelligent, zero-carbon grid. To sum up, it provides:
Cashback for EV owners – selling surplus energy back to the grid.
Does excessive cycling cause a vehicle’s battery to degrade faster? Not necessarily. The single biggest degradation to a lithium-ion battery is time spent at full charge, and with V2G, you’re allowing your car to move to a lower state of charge and get paid for it.
Secondly, the rate at which you charge or discharge energy from the battery is an important factor, and anode health can actually be improved by low power, high-frequency cycling, which is how V2G energy transfer is managed.
So V2G is a force for good, not only in providing a quick and cost-efficient form of local energy storage but developing a more democratic energy management system where everybody can benefit.