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 Jens Hagman, Researcher 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 Jens Hagman.

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 Jens Hagman.

"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, Director Electromobility 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.

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.

Hagman 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 Jens Hagman.

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.

At the end of October 2024, a delegation from RISE travelled to Seoul to meet several research institutes and technology giants Samsung and Hyundai on their home turf. Back in 2023, RISE signed a Memorandum of Understanding (MOU) with representatives of four South Korean research players and research funders. The aim? To strengthen cooperation between Sweden and South Korea in three areas: shipping, semiconductors and autonomous vehicles.

But the story doesn't start there - it goes back 40 years. Paul Halle Zahl Pedersen, Head of Safety and Transport at RISE and one of the nine delegates in South Korea, gives us the background:

"The Swedish shipbuilding industry both built and tested in Sweden until the 1980s, when production moved to China, South Korea and Asia in general. The new shipyards and shipbuilders in South Korea then started to buy testing services from the Swedish National Ship Testing Institute (SSPA), which is now part of RISE," says Paul Halle Zahl Pedersen:

"So there has been commercial activity between South Korea and maritime testing centres in Sweden for a very long time. Gradually, the cooperation has evolved from purely commercial to a solid research collaboration.

Focus on the greening of shipping

The green transition of shipping has become an increasingly important area of investigation in this research collaboration. Discussions in Seoul focused on wind propulsion, batteries and the combination of fossil-free fuels with different types of sails. As South Korea builds 15 per cent of the world's ships, this is a burning issue. Sweden and RISE, which has long been researching how the maritime industry can reduce its emissions, are keen to contribute to the development of energy-optimised ships and more sustainable fuels.

Paul Halle Zahl Pedersen emphasises that South Korean players are always looking for excellence - and in this case they have found it in Sweden. "South Korea has a high regard for Sweden's technology infrastructure, not only in the maritime sector, but also in the automotive industry.

"There is a lot of interest in AstaZero and SEEL, our unique test and demonstration centres for research and development in electromobility and autonomous vehicles. The fact that Sweden has a leading automotive industry with Volvo, Scania and others is also attractive," says Paul Halle Zahl Pedersen.

He continues:

"For Sweden and RISE, it is incredibly interesting to work with South Korea, which has large industrial locomotives such as Samsung and Hyundai. We can learn a lot from the way South Korea works through research cooperation.

Semiconductors for the future

Alongside shipping and autonomous vehicles, semiconductors are high on the agenda for cooperation with South Korea. Together with KTH Royal Institute of Technology, RISE has researched and developed a special type of semiconductor that can withstand higher temperatures and electrical voltages than conventional types. With a partner like South Korea, which is experienced in large-scale production, the automotive industry's demand for these energy-efficient semiconductors could be met.

"This type of partnership is crucial for Sweden to compete with China and the US in power semiconductor technology," says Paul Halle Zahl Pedersen.

Potential for expanded cooperation

During the visit, the delegation took the opportunity to lay the groundwork for expanded cooperation with South Korea. They talked about expertise in the bioeconomy and the new pilot plant in Örnsköldsvik, where biomass is used to produce everything from new foods to bioplastics. Interesting, the audience thought.

"We have had incredibly talented people working in South Korea for a long time, building relationships that are now opening doors in areas other than maritime. I think what is happening now is extremely important for European and Swedish competitiveness," he says.

Your phone has it. Probably your car keys too, and maybe soon your fridge. As more and more products become connected, semiconductors are becoming a critical component. And, as the pandemic supply disruption showed, they are mostly made outside Europe.

For the time being.  

Europe's dependence makes many companies vulnerable

Because right now, until the end of 2023 and the next few years, work is underway on the European Chips Act, an EU initiative to support European semiconductor manufacturing. At the same time, security work is underway on RISC-V, and these are just two of the many elements of the EU's digital sovereignty programme.

"Europe is currently dependent on the outside world for both hardware and software," says Björn Forsberg, a researcher at RISE.

"A large part of European companies' value chains cannot be filled with European technology or European services in the current situation. This makes both companies and countries vulnerable, which is what the Digital Sovereignty initiative aims to address."

Firstly, to reduce threats: no one wants to be in the situation we were in during the pandemic, when European companies had difficulties in obtaining critical components. Nor does anyone want to risk being blackmailed in a trade war. Second, to give a real boost to European innovation in the digital sector.

"These efforts, especially in the area of open source, will bring huge benefits to the European economy because common standards make it easier to collaborate on research and innovation. Now everyone doesn't have to reinvent the wheel for every project, but can work together much more easily."

Defining standards is an opportunity for research and business 

And it's not just about semiconductors. The focus on digital sovereignty covers a wide range of things: GDPR legislation to ensure that European data does not fall into the wrong hands, work on RISC-V to strengthen data security, but also investment in standards, open source and other software. Björn Forsberg says that although the work on digital sovereignty is a few years old, it is now entering the really exciting phase from a business perspective.  

"Right now we are in a very interesting time, both in terms of hardware and software design, because the standard is being defined. This means huge opportunities for Swedish research and Swedish companies, but you can't just sit back and wait."

It's a call that applies to all industries, whether it's self-driving trucks or microchips. But what do you have to do to influence the development? Björn Forsberg says you have to start with yourself, find out what your needs are, how the current ecosystem meets them and what is missing.

"Then it's time to get involved, or at least inform yourself about how this ecosystem should be built to be as attractive as possible. The most important thing is not to be on the outside looking in, because if you are on the outside looking in on big emerging standards, sooner or later you will be overtaken."

It is good to have an outside perspective to find new business opportunities 

Getting to grips with the digital sovereignty initiative is not the easiest thing to do, precisely because it covers such a wide range of areas. RISE has specialists in virtually all the areas involved. That means not only expertise, but also business intelligence and an understanding of how all these pieces fit together.

"Even if companies know their own business best, it can be good to get an outside perspective on the whole. Otherwise, there is a risk that companies will only look for solutions to problems they already have, but miss all the opportunities that exist if they look at the whole picture."

And Björn Forsberg believes that waiting is a risky strategy.

"If you jump in now, you avoid solving the fundamental problems, but at the same time you have every opportunity to influence future standards. On the other hand, if you wait a few years, you won't be involved in developing the standards that will dominate the ecosystems for a long time to come. That is when things can really get done."

Hans Christian Ørsted and André-Marie Ampère

In 1820, the Danish physicist Hans Christian Ørsted showed that magnetism and electricity are related, by showing that a compass needle deviates from north in the vicinity of an electric current. This is because the current creates a magnetic field around the electrical conductor that affects other magnetic fields nearby, in this case the compass needle’s magnetic field.

Ørsted’s discovery inspired the French mathematician and physicist André-Marie Ampère to further research the connection between electricity and magnetism. He discovered that two current-carrying conductors exert an attractive force on each other if the direction of current is the same in both conductors, and that they repel each other if they have the opposite direction of current.

Systems of measurement units emerged

Over time, the need for a standardised measurement unit system for electricity grew:

• In 1893, the IEC (International Electrical Congress) proposed that the ohm and ampere should be the base units of a common system of units of measurement.
• At the 1921 General Conference on Weights and Measures in Paris, the ampere was formally added as a unit of electric current.
• In 1948, the definition of an ampere was decided, a definition based on André-Marie Ampère's discoveries more than a hundred years earlier.
• In 1960, the ampere officially became one of the base units of the SI International System of Units. 

The impossible definition of the ampere

The decision in 1948 meant that 1 ampere was defined as the current which, when it passes through two infinitely long, straight, and parallel conductors, with negligible cross-section and one meter between them, generated a force of 2x10^-7 newtons per meter between the conductors.

Note that based on this definition it seems impossible to realise, bring into reality, exactly one ampere. It is not possible to manufacture two infinitely long conductors. But the definition still made it possible to make a practical realisation of the ampere through a device known as an ampere balance, where a known mass is balanced against an electromagnetic force from the current in several coils. Through accurate measurements of the dimensions of the coils, the current could be determined with sufficiently small measurement uncertainty.

Ohm’s law

Formulated by the German scientist Georg Ohm in 1827, Ohm's Law describes the relationship between electric current (amperes), voltage (volts) and resistance (ohms) and is one of the simplest and most useful equations in physics:

I = V / R

where I is the current, V is the voltage and R is the resistance. This means that if two of the values are known, the third can be calculated using the formula. If the voltage and resistance of a circuit are known, the current can be easily calculated.

The three units thus belong together. To understand it, you can make a simple comparison with a water system, where voltage corresponds to the water pressure, the current corresponds to how much water flows in the pipe and the resistance corresponds to the diameter of the pipe. If you know the diameter and the water pressure, it is easy to calculate how much water flows. In the same way, it is easy to calculate the pressure if you know the diameter of the pipe and how much water flows through the pipe.

Reverse measurement

In the 70's and 80's electrical measuring instruments started to get so good that the ampere balance did not suffice. At the same time, scientific breakthroughs in quantum mechanics made it possible to realise volt and ohm based on natural constants. With the help of Ohm's law, it was then possible to determine ampere with very small measurement uncertainty.

Volt is realised using the Josephson effect and ohm using the quantum hall effect. These quantum mechanical phenomena have both been awarded Nobel Prizes and have changed the way we define and measure these quantities.

The derived units volt and ohm were thus used to realise the ampere. This clearly seems backwards. The idea was that the base units in the SI system would be used as the base for the derived units, not the other way around. The reason for this was that voltage and resistance could be measured with much less measurement uncertainty than electric current. The problem, however, was that this method was not based on the definition of ampere, even though the realisations of volts and ohms are very accurate.

Redefining the ampere in 2019

In 2019, the definition of ampere within the SI system was changed. Instead of being based on the force between two infinitely long electrical conductors, the ampere is now defined via the value of the elementary charge e. The elementary charge was also given a fixed value of 1.602 176 634 ∙ 10^-19 C, where the unit coulomb, C, can be expressed as A∙s, ampere times second. This means that one ampere corresponds to a charge flow of 1 coulomb, i.e., approximately 6.241 509 074 ∙ 10¹⁸ electrons, per second. Through this redefinition, the realisations of volt and ohm also became correct according to the SI definition.

The National Laboratory for Electrical Quantities

However, the new definition does not make it easy to realise ampere based on its definition. It requires extremely accurate counting of an incredibly large number of individual electrons. Although possible, the technology is in its infancy and needs further development. In practice, Ohm's law and realisations of volt and ohm through the Josephson effect and the quantum hall effect are therefore still used to realise the ampere. It is this method we use to realise the national standard for ampere at the National Laboratory for Electrical Quantities here at RISE.