News item | 2012-12-17 | 15:10 PM

E-mobility news: User test of wireless charging for electric cars in new project

An important part of the Vattenfall E-Mobility R&D program is initiating and taking part in projects where future charging solutions for electric vehicles are developed and tested. In a recently started demonstration project, Vattenfall R&D and the Viktoria Institute continue their collaboration on automatic inductive charging, together with several other partners. Many people agree that electric cars and plug-in hybrids play an important future part in a sustainable society. Fewer people know that the electric car has the potential of becoming the most convenient type of car to own and drive. Many car manufacturers are currently investigating how charging can be made automatic and more user-friendly. By using wireless technology, electric cars may never have to be manually “refuelled”.

The WiCh (Wireless Charging) project logotype. Illustration: Viktoria InstituteThe WiCh (Wireless Charging) project logotype. Illustration: Viktoria Institute.

Automatic charging is predicted to have a gradually more important function, because of the increased market share of plug-in hybrids. Plug-in hybrids, which can be driven on electricity as well as diesel or petrol, have a relatively small battery and therefore need to be recharged more often to use the electric drive as much as possible. If the charging is made automatic, drivers will hopefully charge more often and therefore the distance driven on electricity will increase.

WiCh (Wireless Charging of electric vehicles) is a recently started project with the aim to investigate how electric car drivers experience wireless charging and whether this new technology will affect their charging behaviour. The project will also investigate if the wireless technology can live up to the promises made by its producers, in terms of electrical efficiency and safety. A number of electric cars will be adapted for wireless charging and will thereafter be used for different operations in Stockholm and Gothenburg during 2013 and 2014. The drivers in the user study consist of regular people who use the electric cars in their profession, and will now have the wireless charging equipment mounted in their cars.

Wireless charging of electric cars is still in an exploratory phase. Recently, the technological maturity has reached a phase where it is possible to use it for demonstrations, and it will probably become an option with many car manufacturers in the near future.

The wireless technology used in the project has strong connections to magnetic resonance. A charging plate will be placed in the ground and a collector is mounted on the car’s belly. The aim for the final solution is that the car will start charging automatically, as soon as it is parked above the charging plate. The energy is then transferred wirelessly over an air gap of 150 to 200 mm. Producers of this technology claim to reach an electrical efficiency of more than 90 % under these circumstances. Verifying the electrical efficiency is one of the project’s goals.
The plan is to give the first users within the WiCh project access to the cars during the spring of 2013. Thereafter, the number of cars will be increased, to reach full scale (around 20 cars) during 2014.
Vattenfall sees automatic inductive charging as one of the main charging technologies for the future.

– My vision is that automatic charging solutions will make plug-in hybrids and pure electric cars even more attractive to the customer than conventional cars, says Johan Tollin, head of E-Mobility R&D at Vattenfall.

Participating organizations in the research and demonstration project WiCh (Demonstration and evaluation of Wireless Charging of electric cars) are (in alphabetic order):

  • City of Gothenburg’s Public Transport Authority,
  • City of Stockholm Urban Environment Division,
  • Göteborgs Gatu AB (Gatubolaget),
  • Göteborg Energi,
  • Viktoria Swedish ICT,
  • Swedish Radiation Safety Authority,
  • Test Site Sweden and
  • Vattenfall.

The WiCh project (2012-2014) is made possible by grants provided by the Swedish Energy Agency.


Tommy Lindholm