Plugging in to the Future: Developing Electric Vehicle Chargers for an Evolving Grid

This article was originally published in Thinkers & Makers, a magazine from Akkodis featuring the smartest minds and innovative projects that are driving the future of technology and engineering.

Demand for electric vehicles (EVs) is on the rise. Ensuring that charging infrastructure can meet that growing demand and keep the increasing numbers of zero-emission cars on the roads is challenging. There’s more to it than simply installing extra plug sockets. 

As the world strives to decarbonize, electricity is becoming increasingly important, and the electricity grid is evolving.

The grid needs to become more dynamic and flexible to keep pace with the growth of fluctuating renewable energy sources such as wind and solar. Meanwhile, digitalization is enabling the interconnection of systems and infrastructures. New digital e-mobility services are shaking up the world of transportation and logistics.

Changing Role 

The role of EVs is evolving. They are no longer just energy consumers but active participants in the electricity grid. Researchers predict that by 2050, the collective storage capacity of European car batteries will be around 3 GWh. This capacity could be used to store fluctuating renewable energy flows. 

But for that to happen, several pieces of the electricity puzzle must fall into place. Cars need to be capable of delivering current from their batteries through the charging cable into the grid. Charging stations must transform the power from alternating current to direct current for the car. Charging stations should also change the direct current coming from the vehicle to alternating current for the grid.

Cars need to communicate with the demand side of the grid so grid management can establish an overview of storage capacity and energy demand. 

A secure and precise billing system is crucial for tracking and compensating for the energy exchanged between vehicles and the grid. 

All that and the complex technology that underpins it should never make for a complex user experience. Gone are the days when the average EV buyer was a person with a particular interest in technology who was willing and able to handle a demanding device interface. 

As EVs become more widespread, ease of use and intuitive design are prerequisites.

Marianne Holmstrom, DEFA Power EV Charger Project Owner

Future-oriented Standards

EV charging is crucial to the electricity system of the future, but making that role a reality is technically complex.

Akkodis Norway has developed a state-of-the-art DEFA Power EV charger. It offers the latest, most future-oriented standards with simple and intuitive handling. DEFA Power is designed to function worldwide, as it will be marketed internationally, with different versions meeting local regulations and requirements.

The team, led by project owner Marianne Holmstrøm, set out to develop a whole new product generation from scratch. The technical platform had to be future-proof and ready to handle all the latest functionality needed in the coming years. The charger itself had to be as easy to operate as possible.

The DEFA Power charger is designed to provide a more intuitive and seamless charging experience than its competitors. Its integrated display gives the user step-by-step information about the charging process. The charger has an app that calculates the optimal charging procedure to save time and money.

Such a complex project requires collaboration between supplier and customer. Holmstrøm’s team has worked closely with hardware and mechanics experts from DEFA, who gave Akkodis' experts the freedom to develop the best solutions, she said. 

“Electronics and mechanics must align well. In the project's first phase, we contributed to the electronics while DEFA worked with the mechanics. Afterward, we worked together writing the high-level application code that lets the charger communicate with the backend systems it interacts with.”

“It has been a great collaboration because DEFA has such a strong skill set in mechanics and software. They are very serious about designing robust, complex, high-quality products”.

Marianne Holmstrom, DEFA Power EV Charger Project Owner, Akkodis Nordics

Software Focus 

The two partners have been working closely on software development, a vital part of the project.

“The software controls the interaction between a group of chargers when they are part of a larger installation at a shopping center or in a residential area,” Holmstrøm said. “Here, load balancing becomes important. The current available locally is distributed evenly between chargers, optimizing the use of the local network.”

“The Akkodis Norway team has been closely involved, and we feel that we have contributed to this project, both in electronics design and software. It has been a great collaboration because DEFA has such a strong skill set in mechanics and software. They are very serious about designing robust, complex, high-quality products,” Holmstrøm added.

Security and Performance

The charger complies with all standards for electronics safety and is secured against hacking, preventing unauthorized charging. It is also designed to deliver its maximum charging capacity of 22 kW, which sounds obvious but makes it unique. 

Many existing chargers on the market are known to derate (or operate below their stated maximum capacity) in warm weather or direct sunlight. 

In hot temperatures, the charger automatically reduces the current and charges more slowly to avoid overheating.

DEFA wanted to eliminate that problem and the company’s engineers developed a thermic design ensuring that the charger could dispose of excess heat, even in direct sunlight on a hot day. Instead of encapsulating its electronics in plastic, DEFA’s engineers left the charger open at the back, to deflect heat away from the device.

Since the Nordic launch of DEFA Power in May 2023, the charger has captured about a quarter of the home charging market. At the end of 2023, it was launched in Germany, the Netherlands, Austria, and Switzerland. 

Plans are afoot for further expansion into other countries in 2024, including the United Kingdom and the United States. The company is also working on launch plans for selected markets in Asia.