Solar or photovoltaic 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 UK's sister site, 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 they are expensive and their performance is "poor", Hines 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 five to 10 minutes of talk time by charging one 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 comment, while Sharp was unable to respond by press time.
For these applications to be feasible, there must be "a significant breakthrough in PV technology" to improve energy-conversion efficiency and lower costs, Hines pointed out.
Photovoltaic cells, he said, 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 would 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 unlikely to replace batteries in mobile electronic devices, Hines said. "Instead, they will be used in conjunction with energy-storage devices such as batteries to extend their operating time."
Talkback
The report is correct in saying that performance of individual photovoltaic cells is poor, and that this is a major barrier to adoption. However, even with a major leap in efficiency of PV cells they're still not going to be added to every portable device out there. It's simply not a practical way of charging a device.
There are a number of practical barriers to having solar cells on devices: They only work during daylight hours, and only if you're outside or by a window; You have to keep your device out in the open, which isn't always possible or desirable; You can't have both a solar cell and a display in the same place on a device, so you can either use it or charge it, but not both.
There are better solutions to keeping mobile devices charged while out and about. Obviously as higher capacity batteries are developed they will improve the situation, but <a href="http://news.zdnet.co.uk/communications/0,1000000085,39616139,00.htm">standard charger inputs</a> will mean that Cafés or other retailers — hair salons and sports centres spring to mind — can provide charging points that most of their customers will be able to use.
As both the article and Jonathan have already stated such technology's are simply not punching above there own weight as of yet but that doesn't mean to say that one day they wont, both solar powered devices along with kinetic energy generators will mature.
But in order for this to happen there needs to be more awareness and substantial decrease in the cost and one way to do this is to deploy the technology in the correct fields for the masses asap, this will help with both the cost's and gaining of new idea's or improvements to existing ones to advance the technology even further.
Its all very well having a great idea but if its left on the shelf then it will never flourish and grow, even if that means it ends up growing in a completely different light to the one you anticipated.
In a world with a bit more common sense and a little less greed all our roofs would be solars feeding battery storage area's and or putting surplus back into the national grids, buildings would make more use of technology's such as automatic lights combined with motion sensors and alternative heating, and do we really need automatic doors whats wrong with sticking dynamo's in them?
A great many things in this world can be changed for the better if we change our perceptions of existing technology's.
This not all failure as suggested. For example I have an analogue wristwatch (as in physical moving hands) that is entirely solar powered. I've had it for about 7 years now and in that time it has never stopped. I don't treat it in any special way, and if I remember rightly it can run for several days without any light at all. It is sealed and totally waterproof, which is nice.
Why are they only looking at the special case of a 'full featured' mobile phone? What about a low level voice & text only device? Instead of an all or nothing approach designers should more be looking at 'what can we do now'.
As another example, I would guess that many solid-state music players could be effectively solar powered, whereas a larger hard drive version with video capability etc. would have little chance.
Thats exactly my point just by changing the approach can make the biggest of differences Trevor Baylis's company already have launched a wind up hand held media player with screen, granted it is small but it works a treat.
Trouble is to many people end up thinking about all the things they can't do with the technology, when they should be embracing the things they CAN apply it to instead.