Imagine driving an electric car that can be charged without plugging in, no wires needed.
You can park at your local shopping center and your car will start charging automatically as soon as you get out of your car. Once you get home, your car may start charging as soon as you park it in your garage. Your EVT may not need to be charged at home for long, as you will drive along the charged road.
Wireless charging for EV promises to make this dream a reality. It has the potential to be the ultimate charging technology, where drivers can drop, lock and charge their EVT for a stress-free charging experience with maximum convenience.
Theoretically, wireless EV charging works on the same basis as induction charging for smartphones, which typically uses the Qi Wireless Charging Standard. An electric current is sent through a coil, creating an electromagnetic field that acts on a second coil at a short distance to generate a similar electric current. This current is then transferred to the car battery, charging it.
Currently, the automotive industry is exploring two applications of this scientific principle. These are pad-based wireless charging and wireless charging infrastructure built into the roads.
Pad-based (static) wireless charging
To charge a smartphone wirelessly, users have to properly place their phone on a special pad, while owners of inductive charging for electric vehicles have to carefully drive their EV over a special pad placed on the floor of their garage (or in the future, a parking spot in a multi-storey carpark). . When at home, the pad itself is connected to a wallbox or other power outlet via a cable.
While pad-based wireless charging options currently have limited availability, some car manufacturers are testing the technology in specific overseas markets.
BMW is one of the makers of this car, which introduced the technology in 2018 on its 530e iPerformance PHEV. The system consists of two components, a pad on the floor (called a groundpad in the BMW Lingo) and a charging plate mounted on the underside of the vehicle. , Called CarPad.
As the car approaches the groundpad, its iDrive infotainment system displays a graphic that helps the driver to fully align their car with the groundpad.
When aligned, the charging plate is only three inches away from the groundpad, and BMW claims that the system has a charging rate of 3.2kW, enabling the car to fully charge its battery in about 3.5 hours. BMW claims that 85 percent of the energy is transferred from the groundpad to the car.
The company tested the program in Germany and the United States (as a 36-month lease) in mid-2019, but the program has not been expanded since.
Hyundai’s luxury brand, Genesis, is another car maker testing wireless charging technology for electric vehicles. In the Korean market, its new GV60 EV, based on the dedicated E-GMP electric vehicle platform, can be equipped with a wireless charging solution developed by the American company WiTricity.
Unlike the BMW system described above, the WiTricity system in the new GV60 can charge up to 11kW with an efficiency of 90 to 93 percent. Genesis claims that, using wireless charging, the GV60 can be fully charged in six hours, compared to ten hours when the car is connected to a conventional wall charger.
Despite these improvements, pad-based wireless charging technologies for electric vehicles still suffer from shortages that hinder their widespread adoption. Cost remains a major problem, these systems are usually an additional expense on top of an already expensive conventional wallbox solution.
Performance (the amount of energy generated by the ground-based pads held by the vehicle) is a problem, even with a 93 percent efficiency rating, such as those found in the GV60, falling short of the optimal efficiency achieved when plugged in. A cable
Road-based (dynamic) wireless charging
Perhaps the closest technology to Mario Kart-style ‘boost’ tiles will come, the goal of road-based wireless charging is to charge your electric car while you drive on a normal asphalt road. This technology is more than just static pad-based wireless charging in its infancy.
Road-based wireless charging systems operate on the same principle as described above, but extend it by burying a few copper coils just below the asphalt, creating an electromagnetic field across the road. A car equipped with a suitable receiver then receives current from a series of coils as soon as the car is charged while driving.
Stellantis is the latest car manufacturer to demonstrate the effectiveness of this technology by creating a 1.05 km circuit in Italy and then driving the new 500e at normal highway speeds.
The company claims that the car battery did not run out while driving and that the overall efficiency of the system is comparable to that of a public DC fast charging station.
Detroit, also known as the Motor City, will be one of the few locations in the world to test this technology on a public road in 2023. The Michigan Department of Transportation Electrician has awarded a contract to an Israeli company to build a mile – a long stretch of road equipped with wireless charging technology that can operate whether the vehicle is stationary or moving.
In West Lafayette, Indiana, the Indiana Department of Transportation Purdue University and the German startup Magambi are working with GmbH to create magnetic concrete that will facilitate the development of a public wireless charging road.
Costs remain the primary obstacle to the widespread adoption of this technology, as any rollout is likely to be part of an infrastructure project that requires significant government investment and potentially a public-private partnership. This will be difficult to support when most EVs currently on the road are not properly equipped to use wireless charging.
In addition, as it becomes universally available, the technology will be able to charge everything from small EVs to large utilities and commercial vehicles, and it is currently uncertain whether vehicles with large batteries or increased power consumption can be effectively charged using this infrastructure.
Safety is also a legitimate concern for pedestrians to ensure that there are no adverse health effects due to electromagnetic radiation and electromagnetic radiation.
In his experiments, Stellantis claimed that the electromagnetic radiation produced by a wireless charging rod posed no health hazards and that asphalt acted as an effective insulator to reduce the risk of electrolysis.