Cordless, Wireless EV Charging: The Future of Electric Mobility
Wirelessly charging electric vehicles (EVs) are gaining significant traction in the vast electric mobility landscape. This innovative technology, often referred to as cordless EV charging, paves the way for a hassle-free charging experience, eliminating the need for physical cables. This transformational shift in EV charging could revolutionize the industry and enhance the convenience of owning and operating EVs.
Understanding Cordless EV Charging
Cordless EV charging, also known as wireless EV charging, operates on the principle of magnetic induction, a method of transmitting electrical energy across an air gap between two coils. One coil, located in the charging pad, generates an electromagnetic field. The other, placed in the vehicle, receives this field and converts it to electric current, thereby charging its battery.
Multiple wireless EV charging technologies are developing, including inductive, resonant, and capacitive charging.
- Inductive Charging: This technology uses magnetic coils to transfer power between the charger and the vehicle. It is the most widely studied and utilized form of wireless EV charging.
- Resonant Charging: A variation of inductive charging, resonant charging uses tuned circuits to improve power transfer and reduce energy loss. It can increase the gap and misalignment tolerance between the charger and vehicle, allowing multiple vehicles to charge from a single source.
- Capacitive Charging: This method uses electric fields, rather than magnetic fields, to transfer power. It requires metal plates attached to the charger and vehicle, creating a capacitor. Though capacitive charging can achieve high efficiency and power density, it demands a large surface area and a small gap between the plates.
Dynamic Wireless EV Charging
Another exciting method of wireless charging is dynamic wireless EV charging. This revolutionary technology enables EVs to charge while in motion. This advancement could extend driving range, enhance vehicle efficiency, and decrease the need for large batteries and charging stations.
There are various types of dynamic wireless charging systems, including high-power, low-power, and hybrid systems.
- High-Power Systems: These systems can transfer hundreds of kilowatts of power to EVs at highway speeds. However, they require complex infrastructure and are cost-intensive.
- Low-Power Systems: These systems can transfer tens of watts of power to EVs at low speeds, but they have a limited impact on the battery state of charge.
- Hybrid Systems: These systems combine high-power and low-power systems to optimize performance and cost of dynamic wireless charging.
Some challenges faced by Dynamic wireless charging include safety, standardization, regulation, and public acceptance.
The specific safety concerns of dynamic wireless EV charging are mainly related to electromagnetic field (EMF) exposure and interference that may occur when the vehicle passes over the charging pads on the road. The EMF may affect the vehicle’s electronics, the passengers’ health, and other nearby devices.
However, its potential benefits include:
- Reducing greenhouse gas emissions.
- Improving traffic flow.
- Enhancing user convenience.
- Enabling new mobility services.
Wireless EV charging offers several compelling benefits:
- Convenience: Wireless charging eliminates the hassle of finding a plug or carrying a charging cable. Users can simply park their vehicle over the charging pad and let it charge automatically.
- Safety: Cordless EV charging reduces the risk of electric shock or damage to the cable or plug. It also minimizes clutter and potential hazards of cables in streets or parking lots.
- Efficiency: Several studies have shown that cordless EV charging can be as efficient as, or even more efficient than, plugging in. For example, WiTricity, a leading wireless charging equipment supplier, claims its products are around 99% efficient.
Challenges of Cordless EV Charging
Despite its benefits, cordless EV charging faces several challenges:
- Cost: Installing and maintaining cordless EV charging infrastructure can be more expensive than traditional charging solutions.
- Compatibility: Cordless EV charging lacks standardization, meaning different systems might not be interoperable.
- Alignment: Precise alignment between the coils is required for efficient charging, which means vehicles must be parked exactly over the charging pad.
Market Outlook for Cordless EV Charging
The global wireless electric vehicle charging market will grow significantly over the next decade, estimated to reach approximately USD 450 million by 2030. This growth is driven by:
- The increasing adoption of EVs.
- Technological advancements in wireless charging.
- Growing consumer demand for convenience and efficiency.
- Increasing support from governments for clean energy initiatives.
Cost-effective of Cordless EV Charging vs. wireless charging
The current cost comparison between cordless EV charging and traditional charging solutions depends on various factors, such as the electricity rate, the charger type, the installation cost, the commercial charging fee, the EV tax, and the deadhead miles.
According to some studies, corded EV charging may be more expensive than wireless charging solutions due to the additional costs of home chargers, commercial chargers, taxes, and driving around to find a reliable charger.
Cordless EV charging may offer some benefits, such as convenience, time-saving, and autonomous charging. Therefore, the cost comparison may vary depending on each EV driver’s specific situation and preference.
Noteworthy Developments in Cordless EV Charging
Some efforts are being made to standardize cordless EV charging systems, especially for the inductive wireless charging technology.
The Society of Automotive Engineers (SAE) published the first global standard for wireless EV charging, SAE J2954, which specifies the electric vehicle and supply equipment ground-system requirements for wireless charging up to 11 kilowatts.
This standard aims to harmonize the wireless charging systems and enable interoperability between vehicles and chargers.
Several companies and research institutions are working to improve the performance, reliability, and accessibility of cordless EV charging systems. These include:
Char. gy: A UK-based company that provides wireless charging services for EVs. The company has installed wireless charging pads in public parking spaces in Buckinghamshire, UK, as part of a 12-month trial.
Oak Ridge National Laboratory (ORNL): The US Department of Energy’s laboratory has been conducting research on wireless EV charging for several years. In 2020, it announced a project to develop dynamic wireless charging, allowing vehicles to charge while driving on specially equipped roads.
EV Manufacturers Embracing Cordless Charging
Several EV manufacturers offer or plan to provide cordless charging options.
The Genesis GV60, the first electric car from Hyundai’s luxury line, offers wireless charging capability supplied by WiTricity. The vehicle’s wireless charging system can deliver up to 11 kW of power wirelessly and is compatible with the J2954 wireless charging standard.
The Mercedes-Benz S550e, a plug-in hybrid luxury sedan, offers an optional wireless charging feature for its 19-mile electric range. The charging system, developed by Qualcomm, can deliver up to 3.6 kW of power wirelessly.
WITH WIRELESS CHARGING TECHNOLOGY, the BMW i8, a plug-in hybrid sports car, has been used as a pace car in Formula E racing. The vehicle’s charging system, developed by WiTricity, can deliver up to 11 kW of power wirelessly.
Cordless EV charging is a promising technology that could significantly enhance the user experience of electric mobility. While it might not immediately become the new standard for EV recharging, a future where EVs charge seamlessly and effortlessly, without cables, is close. As the technology continues to evolve and improve, the widespread adoption of cordless EV charging could revolutionize the EV industry and propel electric mobility into a new era of convenience and efficiency.