Vehicle-to-Grid (V2G) technology allows energy from an electric vehicle to be sent back to the grid. This can benefit businesses and individuals, as well as society as a whole. The challenge now is to get all the technical solutions and new business models in place to enable commercial deployment.
Demand for electricity is expected to grow significantly in the coming years.
At the same time, we need to maintain an energy balance, meaning that every second as much electricity is fed into the grid as is consumed.
The growing fleet of electric vehicles – electric cars and trucks – is itself an opportunity to ensure energy balance. The energy in electric vehicle batteries has the potential to stabilise the grid when demand is highest.
This is where vehicle-to-grid (V2G) technology comes in. As it sounds, it involves feeding energy from a vehicle back into the grid. A vehicle battery then becomes an energy storage device that is connected to the grid to perform a kind of reverse refuelling.
Greater electricity demand in the future
This technology can bring many benefits, not least to society as a whole.
"At present, the electricity grid requires very large transmission capacity just to move electricity from the generation source to the user. "So the electricity grid may need to be significantly expanded in the future if there is more demand for electricity and power, but if we can access energy and power in batteries during certain peaks in electricity use, the expansion will not be as urgent," says Johan Mörck, Head of Sustainable Transport and Systems at RISE.
Another challenge is that there needs to be an even frequency in the electricity grid for it to work at all. When there is an imbalance between production and consumption, frequency fluctuations occur and at some point stabilising resources – such as batteries – are needed.
"By having many different resources that can be used for frequency regulation, we get a more reliable power grid," says Johan Mörck.
Flexibility is valuable
A well-functioning electricity grid is the foundation for the ongoing electrification of society as a whole, which is expected to take place in the areas of transport and industrial production.
"Anything that can help stabilise the electricity grid, including the electrification of industry, has a clear climate benefit," says Johan Mörck.
"If V2G is established, it can be a powerful addition as a regulating force for the electricity grid. But it also provides an important societal benefit in the form of resilience," says Anna Larsson, Head of Energy Transformation at RISE.
"In the event of a crisis that affects the electricity supply, flexible energy storage is extremely valuable. For example, the system could be knocked out in a conflict, or there could be a major blackout affecting large parts of the country. If the vehicles are equipped with bi-directional on-board chargers, large vehicles with charged batteries can provide electricity where it is needed," she says.
A new ecosystem is needed to manage these transactions
Creating a new ecosystem
At the same time, V2G opens up new economic opportunities for both companies and individuals.
"Firstly, anyone who owns an electric vehicle with V2G would have the opportunity to sell frequency regulation services to Svenska Kraftnät by making their car battery available for V2G. The same applies to companies that have large fleets of vehicles that are parked for certain periods of time", says Anna Larsson.
Another example would be to use the batteries in cars parked for long periods at an airport.
Mörck notes that a number of different players will be able to generate revenue through V2G – but it is not yet clear which ones.
"A new ecosystem will be needed to handle these transactions. Vehicle owners are one party, but you can also imagine network companies and vehicle manufacturers being involved in some way," he says.
He also sees new types of players starting to establish themselves and take their place in the emerging ecosystem.
"Companies that offer intermediary services of various kinds can be an important part of this chain. For example, it is unlikely that a private individual would contract directly with Svenska Kraftnät without an intermediary."
Policies and agreements needed
So V2G has great potential on several levels, but some pieces of the puzzle are missing before the technology can be widely used.
"There are currently only a few car models on the market that are prepared for V2G, and more vehicles and bi-directional chargers would be needed to test and evaluate different solutions in practice," says Anna Larsson.
Standardisation of how to handle the transfer is well under way, but there is still a lot of research and testing to be done, for example on communication with the electricity grid. There is also a need to develop the network's control and metering systems.
"There are also some unanswered questions, not least about how business models, policies and agreements should be designed; we are investigating in several projects at RISE what the interaction in the ecosystem for V2G might look like," says Johan Mörck.
Research on V2G is ongoing at RISE, focusing on everything from the challenges for power electronics to the expected usage patterns.
"It's a complex field that requires expertise in different areas, and thanks to our broad perspective, we can offer collaborations with players in different parts of the field," he says.
Several pilot projects in Europe
V2G stands for Vehicle-to-Grid and is a technology that allows electric cars to not only receive electricity, but also to send electricity back to the grid via a bi-directional charger.
In Sweden, a number of pilot projects and studies are underway in various contexts to bring about widespread V2G use, and there is also cooperation with partners in other European countries – including the Netherlands – where they are also in the early stages of preparing for the implementation of V2G.
To have a real impact, more car models need to be adapted for V2G and a wider range of bi-directional chargers is needed. New software and control systems are also needed to make management work, and legislation, regulations and contracts need to be adapted to V2G.
