Green transportation

High-power charger to supply ultrafast electricity to growing electric car market

In the past year, the proportion of Danes who have an electric car has doubled, and there is increasing strain on the electricity grid. A new battery technology will relieve the electricity grid while providing affordable ultrafast charging.

CEO of the company Nerve Smart Systems, Jesper Boie Rasmussen, has developed a fast charger for electric vehicles. DTU has tested the solution, and the first units are now on the market. Photo: Thomas Steen Sørensen

Friday 17 May 2024

Sari Vegendal

Every electric car owner’s green dream must be to drive off in the morning without having to worry about the time and place of the next charging. Jesper Boie Rasmussen, CEO of the company Nerve Smart Systems, has set out to make that dream come true.

“I’m absolutely convinced that we will accelerate the green transition. We’ve developed a technology that enables us to set up high-power chargers in many more places in Denmark without overloading the electricity grid. In fact, they are able to help the electricity grid when it’s under pressure,” he says.

The high-power charger solution, which is a combination of a high-power charger and a battery, provide charging of electric vehicles in record time without straining the electricity grid. Depending on the capacity of the car, the charging time typically corresponds to a coffee break. Meanwhile, the price is kept down through, for example, high-power charging with stored electricity from the battery when the electricity grid prices are high. Finally, the battery can act as a buffer for the existing electricity grid when the demand for renewable energy is higher than the production.

“The pressure on the electricity grid is growing because more and more of the conventional power plants are being replaced by wind turbines and solar cells. Wind and solar energy depends on the wind blowing and the sun shining, so when production drops, it is difficult to match the demand for electricity. The battery is brilliant at filling that gap,” explains Jesper Boie Rasmussen.

He believes that supplementing with batteries can constitute an alternative to an otherwise costly upgrade of the existing electricity grid. While the charging station operator can make money by supplying renewable energy to the electricity grid from the batteries, society can save some of the DKK 110 billion that an upgrade of the electricity grid will cost, according to the latest analysis from Ramboll.

DTU tests have led to approval

The high-power charger from Nerve Smart Systems has not yet been rolled out on a large scale, but it has been fully developed, thoroughly tested, and supplied to the first customers in Denmark, including the energy company OK. Looking back, Jesper Boie Rasmussen would not have succeeded without help.

“I will be the first to admit that it has been a long journey. But we’re now in a place where the product is good, and this is not least thanks to a number of joint projects we’ve had with DTU,” he says.

For example, DTU has contributed with thorough testing of the solution in the University’s experimental energy laboratory PowerLabDK. Here, the high-power charger battery has been connected to a model of the energy system, and, by testing the response of the battery to various electricity grid conditions, such as fluctuations in voltages and frequency, DTU’s researchers have been able to identify faults and deficiencies.

“We’ve used our equipment and knowledge to perform all the tests necessary to obtain an approval to connect to the electricity grid and supply energy. In the end, Energinet, which owns the electricity grid in Denmark, was able to rubberstamp the solution and say yes, now you have the right to operate the battery system,” says Mattia Marinelli, Head of Section and Associate Professor at DTU Wind.

In the final solution, the customer can manage their charging via a touchscreen, which also allows you to stop charging before the 'tank' is full. Photo: Thomas Steen Sørensen

Since 2019, he has collaborated with Nerve Smart Systems on a number of projects, all of which have had the objective to mature the technology of the high-power charger and make it ready to be used in society.

“As a researcher, I’ve been able to look forward to something that has a clear and applicable value, and this means that we can be more pragmatic in the studies we conduct. It’s highly satisfying for me to contribute to something that can support an electrification of the transport sector, thereby promoting the green transition,” says Mattia Marinelli.

Unique battery technology

The key to the success that Nerve Smart Systems hopes will come is a battery system based on the patented battery technology Nerve Switch. The technology makes it possible for the high-power charger, as the only solution on the market, to charge an electric car directly from the battery.

“Normally, you need expensive electronics between the battery and the car to create the voltage that the car needs,” explains Jesper Boie Rasmussen and continues:

"But we’ve made an invention where we can switch the individual battery cells on and off in a battery string, so that we can control the supplied voltage. This means that we can supply energy directly into the electric car and potentially minimize losses.”

In practice, this means that when you arrive with your electric car at a charging station from Nerve Smart Systems, the battery has been charging prior to the visit. Charging takes place in the same way as when a cistern fills up with water. Steadily and calmly. When you connect your car to the charger, the 'lock sluices' to the stored electricity are opened, and the car is directly supplied with a large amount of renewable power in one go. The price is low because the charging has taken place while electricity was cheap, and time is short because the battery supplements the existing electricity grid.

The battery is located inside the charging station and charges up in between the cars refueling. Similar to how a toilet fills its cistern with water, the charging station replenishes its battery so it's ready to deliver a large amount of power at once when a new electric vehicle is connected. Photo: Thomas Steen Sørensen.

There is still some way to go before this routine can become an integral part of every electric car owner’s everyday life.

At DTU, Mattia Marinelli and his team are examining how to control the battery system to ensure that the battery capacity is utilized optimally. And at Nerve Smart Systems, they are putting the high-power charger into production.

“It’s one thing to make a high-power charger that is good. It's quite another thing to make a large quantity of them that are good. In five years, our goal is to streamline mass production and produce the next generations of our high-power chargers,” says Jesper Boie Rasmussen and adds:

”It’s fantastic to have come this far.”

Topic

Green transportation

The transportation sector is emitting more and more CO2 from cars, trucks, planes and shipping. To reverse this trend, more of the known solutions and technologies need to come into play.

DTU is a leader in research and education in key technologies such as green electricity, green fuels, electrification of society and battery technology development.

Read more on the green transportation page.

Contact

Mattia Marinelli Associate Professor, Head of Section Department of Wind and Energy Systems Phone: +45 46774955 Mobile: +45 20124369 matm@dtu.dk