Solar cells for phones still not fully feasible

Vivian Yeo | Aug 19, 2009

Sharp's Solar Phone SH002 launched in June in Japan. (Credit: Sharp)

Solar or photovoltaic (PV) technology in mobile computing devices is still impeded by performance and price issues, and is not likely to entirely replace batteries anytime soon, according to analysts.

James Hines, Gartner's research director for semiconductor, told ZDNet Asia in an email interview that performance is the "primary inhibitor to the practical application of integrated solar cells" in today's mobile devices.

Solar-powered battery chargers for mobile phones and other devices are already available in the market, but are not only expensive but performance is also "poor", he had said in a recent research document.

According to Hines, consumer electronics manufacturers are considering integrating PV technologies into more mobile devices.

In June, Samsung launched the Solar Guru in India, which the Korean mobile maker says has the capacity to provide 5 to 10 minutes of talktime by charging 1 hour in sunlight. Japanese vendor Sharp also unveiled its Solar Phone SH002 in June, the Nikkei Business Publications reported. Samsung could not be reached for comments, while Sharp was unable to respond by press time.

For these applications to be feasible, however, there must be "a significant breakthrough in PV technology" to not only improve energy conversion efficiency but also lower costs, Hines pointed out.

Photovoltaic cells, he explained, currently have a low-energy conversion, while mobile devices increasingly consume more power in active mode. To meet "a significant portion" of the power requirements of full-feature modern mobile devices, the solar panels will have to be larger than the devices, which makes portability more problematic.

"For this reason, products such as the solar-powered mobile phone will probably see limited uptake in the near future," said Hines.

Annette Zimmermann, senior research analyst at Gartner, noted in a document released last month, that "in practice", it takes solar mobiles about a full day to recharge completely. "This will certainly limit the functionality, given that few users have the opportunity to expose their devices openly to the sun for such a long time."

The main selling point of these devices, she added, appears to be the "theoretical convenience for those who do not always have access to electricity", such as in emerging markets. On the other hand, the new technology will most likely have a higher price tag than any low-cost device, which does not match the price expectations of its target market--low-budget users.

Solar not battery replacement
Hines added that solar-powered battery chargers for charging a variety of mobile devices, remain "the most practical application in the near-term".

Such battery chargers could even be integrated into backpacks, laptop cases or garments. However, these are a "supplemental" means of charging--in situations where grid connection is not possible or convenient.

Due to their power limitations, integrated solar cells are not likely to replace batteries in mobile electronic devices," said Hines. "Instead, they will be used in conjunction with energy storage devices such as batteries to extend their operating time."

Via ZDNet Asia

Filed under: Green Tech, Mobile Phones
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