Wireless power industry needs united front

With separate camps pushing different wireless power transmission technology and projects, tech advocate calls for more cooperation to proliferate use.
Written by Kevin Kwang, Contributor on

The technology to enable wireless power over short distance is now mature, but market players will need to work together to ensure their products interoperate seamlessly before the mass market is willing to accept this mode of transfer, urges one advocate.

Menno Treffers, chairman of the Wireless Power Consortium's (WPC) steering group, said there is "no need for technical breakthroughs" to bring short-distance wireless power transfer to the market. Companies such as Palm, with its Touchstone charger, already have equipment in the market that allows for wireless power transfer, Treffers said in an e-mail interview with ZDNet Asia.

He noted that companies such as Palm, Dell Computer and manufacturers of equipment that charges devices wirelessly including WiPower and Powermat, need to work together and ensure there is interoperability within the industry.

To this end, WPC is aiming to bring its specification for wireless power transfer, dubbed the Qi, into the market before the middle of the year, according to a Reuters report.

This specification aims to standardize the technology known as magnetic induction that, simply put, allows power to be transferred between metal coils built into the charging pad and the device. WPC is targeting to deliver power of up to 5W (watts) with at least 70 percent efficiency, which would be able to charge most small devices such as mobile phones. Bigger devices such as laptops, though, would need to wait for a separate standard, the report added.

Treffers said: "We want to start on [the standardization for bigger devices] as soon as possible but for now, we don't want to dilute our engineering efforts."

Among the companies seeking to promote magnetic-induction power transfer, some players--Powermat, for example--are not part of the WPC consortium. Instead, these companies continue to sell their proprietary technology.

WPC currently includes market players such as Nokia, Research In Motion, Philips, Energizer and Duracell.

Powering up over the air
There is also a divergent camp of wireless power advocates that have chosen instead to develop their equipment based on magnetic-resonance induction, or over-the-air (OTA), power transfer.

WiTricity is one of the leading proponents of this technology, and David Schatz, the company's director for business development and marketing, said this method offers the possibility "to charge and power devices at distances that create dramatic user benefits".

Schatz told ZDNet Asia that "proximity-inductive systems" similar to those featured by WPC and Powermat, have been around for many years but have found very limited application and market success.

"We believe that is because they require such careful alignment of the power source and device at close proximity… [These] constraints make such systems not much better than a traditional conductive charging cradle or plug and cord," he said.

Elaborating on the company's latest developments, Schatz said WiTricity, in collaboration with manufacturer Haier, demonstrated how its magnetic-power transfer device was able to power a 100W, 32-inch high-definition television at a distance of 0.5 meters at the Consumer Electronics Show (CES) earlier this month.

But the route to market for this OTA technology will take some time, Schatz revealed, as the company expects the military and industrial markets to come onboard first, fielding test projects with its technology by mid-2010.

"Our first OEMs (original equipment manufacturers) in the consumer electronics market will announce and introduce products in late-2010. Consumers should be able to buy such products in 2011," he added.

According to Treffers, though, OTA power transfer is not feasible. "There is a fundamental problem with magnetic-resonance induction [where] the efficiency drops dramatically if the distance through the air is larger than the coil diameter," he wrote in a blog post last year.

This claim was disputed by Schatz, who said there were many applications in which the efficiency of power transfer was shown to be "well over 90 percent". He cited as an example, a WiTricity cordless charging system for electric cars that is over 91 percent efficient.

In response to critics of magnetic-resonance induction, he said: "[They] can be very shortsighted and misinformed."

Sony is another company that has chosen to support magnetic-resonance induction. The Japanese company announced in October 2009 it had developed a highly efficient wireless power transfer system based the technology, that is able to deliver up to 60W of electrical energy over 50 centimeters and at an efficiency rate of about 80 percent.

A spokesperson from Sony Electronics Asia-Pacific told ZDNet Asia its system is able to keep high efficiency even at long range transfers. It is also robust against "both parallel misalignment and angle misalignment" and with its patent-pending passive extender and rectifier devices, is able to increase the overall efficiency and transfer distance, he added.

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