Volkswagen (VWAGY 1.50%) plans to offer wireless charging for its plug-in hybrids and electric vehicles beginning in about 2017, which would make it the first automaker to offer such a factory option, unless a rival beats it to the punch. If another automaker does cruise by VW on this front, it will probably be Toyota Motors (TM 1.23%), as the Japanese automaker has recently begun verification testing of its wireless technology with the Prius. Nissan Motors, BMW, Mercedes' parent Daimler, and Geely's Volvo unit are also reportedly developing and testing wireless charging tech.

Currently, there's only one wireless charging system available for plug-in EVs, an aftermarket system offered by privately held Evatran and Germany's Bosch, which is available for the Nissan Leaf and Chevy Volt for about $3,000. 

Here's what you should know about this topic.

The technology: akin to a giant wireless cell-phone charging pad
Volkswagen hasn't said anything about the technology it plans to use, but I'd imagine it's very similar to the tech that Toyota is now testing. While the various technologies the automakers are developing might vary a bit, they're all forms of induction charging. This is the same tech that's used in wireless charging pads for cell phones.

With induction systems, the driver positions the vehicle over a charging device (typically a pad installed on a parking spot or actually buried in the parking spot), and the charging starts automatically. The charging device contains an induction coil, which creates an alternating electromagnetic field. When the vehicle is positioned above the device, this field is detected by the receiving device that's installed on the car's underbody. The receiving device, which also contains an induction coil, converts the magnetic field into an electrical current that's used to charge the vehicle's battery.

Toyota Prius wirelessly charging. Source: Wikipedia

How does one go about positioning a vehicle over these charging pads? It's likely that automakers will incorporate positioning systems into their parking-assist systems. Toyota's apparently planning on doing just this, as its testing of its wireless charging system also involves testing a new parking-assist system.

Standardization is an issue here, just as it is with corded charging, as there is no single industry standard. There is progress being made on this front, however, as SAE International, a global auto industry association and standards organization, agreed in November on a frequency range and three power transfer rates for wireless EV charging.

Cool tech, but what are the investing takeaways?
Eliminating the need for a charging cord promises to bring more convenience to those owning or leasing an EV, and anything that makes driving an EV more pleasant should help increase consumer adoption of these vehicles.

Some folks are surely thinking that plugging and unplugging an EV is a small thing. While some people may feel that way, the number of consumers who will pay up for convenience shouldn't be underestimated, in my opinion. Further, in certain settings -- for both consumer and commercial vehicles -- logistical factors might make wireless charging the only option available.

Of course, there is a circularity involved here, as the more consumers buy EVs, the greater will likely be the demand for wireless charging systems. If demand is great enough, early movers in this space could benefit. While this article has focused on the nascent consumer market, it's important to note that wireless EV charging systems have already started making some inroads into the public transportation and commercial vehicle spaces. These non-consumer markets are where the bigger money will likely be made, at least for a while, in my opinion.

Here's a quick look at the major public company players involved in the wireless EV charging space. These are all big companies, so there's not a pure play in the bunch.

Qualcomm (QCOM 3.88%), which sports a $134 billion market cap, is the leading chip supplier for smartphones and tablets. The wireless communications giant expanded into wireless EV charging when it acquired HalolPT in 2011. The bulk of Qualcomm's revenue is derived from licensing its various technologies, and the company looks like it's going to go the licensing route with its Halo Wireless Electric Vehicle Charging, or WEVC, technology, too. Qualcomm's been working with Nissan and others. 

Siemens is a $110 billion market cap German electronics and electrical company operating in the energy, health care, industry, and infrastructure sectors. It's working with BMW on wireless charging technology.

Bombardier is a $6.5 billion market cap Canadian company that manufactures transportation equipment. Its aerospace segment designs and manufactures business, commercial, and specialized aircraft, while its transportation segment designs and manufactures rail equipment and systems. Bombardier's induction charging technology is called "PRIMOVE," and it's already in operation on a light-rail line in Augsburg, Germany. Additionally, the company has supplied its charging pads and drivetrains for buses in a trial taking place in Mannheim, Germany.

The Foolish takeaway
The overarching takeaway here is that EV wireless charging technology is making great leaps and should help further increase the adoption rate of EVs in the consumer, commercial, and public transportation markets.

Investors may want to further dig into the three companies mentioned here, keeping in mind that these aren't pure plays.