Inductive (charging)

Inductive power transfer was developed early in the 20th century, but the high capacity, safety and reliability required by electric vehicles (EVs) is still in early stages of development. Static wireless EV charging (i.e. parking spots, and not an Electric Road Systems (ERS) technology concept) provides a relatively user-friendly and safe avenue to charge electric cars, increasing convenience of use and facilitating adoption. Dynamic inductive power transmission could also be implemented if many inductive units (coils) are installed under the road surface of traffic lanes.
Inductive charging has a number of advantages over conductive charging, but also several disadvantages, including lower efficiency, higher material requirements per lane‚Äêkm, more invasive changes to the existing infrastructure, and more complex components. Dynamic wireless electric charging holds huge potential as it can address classical EV range concerns through 'in-motion' wireless charging, which allows an EV to charge wirelessly as it travels down the road. This also allows for smaller and lighter batteries to be used in EVs, benefitting from charging infrastructure embedded within road infrastructure.
At the end of the electrified segment of road the vehicle can continue to draw from its batteries, switching to its engine when operations warrant doing so or when the batteries are fully depleted. This allows EVs to become more flexible, reduces the need for on-board energy capacity in the vehicles themselves, and can accelerate the operations for which electrification is technically viable and economically competitive (i.e. of long-distance freight and other heavy duty modes). The vehicles using ERS can be hybrid, battery-electric, or hydrogen fuel cell vehicles and can conduct normal driving operations, such as overtaking and driving autonomously outside of electric roads. With a small but growing number of demonstrations in Sweden and Germany, truck operators like Scania are working with Siemens to gain real-world experience operating catenary ERS systems. Installation costs are around USD 1 million or more per lane-km when dimensioned for traffic flows on the core part of the road network (starting at around 2 000 trucks/day), and may fall somewhat from that level in the long term, approaching the magnitudes of rail electrification infrastructure upgrades.