The state of wireless charging of electric vehicles?
Rotterdam tests in practice innovations in the field of electric driving. What can you think of? We are talking about technology, a behavior of e-drivers and a living outdoor space (street view). In short, as a driver in electric driving, we find it important that technology serves the convenience of e-drivers and that our living environment in a busy city remains attractive and practical. In our view, electric driving is the future because the healthier air in an international port city like Rotterdam is not a luxury but a necessity.
For example, we tested the technical state of wireless charging in public space with different partners. Do not lose any loops over the street to a charging pole, but just investigate what happens when you charge your car wirelessly; park over a plate and load it! Wireless charging is ultimately the technique that has been used for a long time to power electric toothbrushes and is also used more and more for charging smartphones or tablets.
The aim of the pilot was to investigate the feasibility of wireless loading in public space, with a specific focus on technology, standardization, safety and user experience. Also, the ENGIE contractor, for whom this is a new development, has looked at a possible business case.
Below is a summary of our findings. We certainly see the future for this technique, but conclude that current technology needs to be further developed. We, therefore, invite market participants to make improvements.
Benefits of wireless charging
Increase user convenience: At startup and departure no extra activities such as packing and connecting a cable. This can be especially interesting for taxi cabins.
Spatial integration: Not or hardly visible in the street view, no cables from car to ramp over a street.
Upscaling options: Easier on a larger scale from the perspective of attractive outdoor space.
Suitable for future mobility: such as self-propelled cars. A fully autonomous vehicle can also charge automatically, plugging in for wireless charging is no longer required, parking above a charging system is sufficient.
To enable Wireless Charging, two magnetic coils are required between which the energy transfer takes place. One of the coils is in the ground and connected to a power source. The other coil is mounted in the vehicle and is connected to both the charging system and the battery of the car. Energy is transmitted through a magnetic field between the two coils; from the coil in the ground to the coil in the car.
The pilot was held in the public outdoor space: Green Kruisweg 36 in Rotterdam from August 2015 to June 2017. The pilot's main activities:
- The conversion of two electric cars
- User tests;
- System installation on the street;
- Measurement of radiation effects;
- Gaining experience with the robustness of the system in the outdoor space;
What have we learned?
We have learned that there is still room for further product-level development (hardware and OEM's) and the subsequent market acceptance. In short; The technique must be further developed to prevent malfunctions. System users have indicated that they find reliability more important than ease of use; The system must be as reliable as charging via a cable before ease of use will play a role.
In addition, the trial has proven that interoperability systems are easier to safeguard in systems that are built in afterward. It is thus possible to charge cars on one system with different types and brands. With cars converted by car manufacturers, this will be a bigger challenge. This requires standardization, especially in the way the car and charging system communicate.
Another important result is that the efficiency of the system is very good, and the distance between the car and the "loading plate" has a limited impact on efficiency. Also, radiation testing has shown that wireless loading is safe and can be applied in the public space.
Despite the maturity, several questions are still unanswered. A possible follow-up should look at the impact of wireless charging on the grid, reducing system components for fully "invisible" fit in public space, and connecting a wireless charging system to current public charging systems management systems. Rotterdam definitely sees future in this technique; We, therefore, invite market participants to make improvements!
Charging technique: the differences between inductive charging or charging via magnetic fields. Which of the two techniques will it be in the near future? The development of load standards by the car bridge determines the speed of rolling out.