Smartphone touch screens could in future double as photo voltaic power panels to recharge batteries. The idea is being developed by French firm Wysips. Their approach is to it add a super-thin transparent photovoltaic (pv) film layer to the phone’s screen. This film is designed to take energy not only from the sun, but from any nearby source of light.
Current recharge times are up to six hours from sunlight and some minutes longer from leaching electricity from indoor lighting. Wysips are now working on the second release of the technology which aims to supply half an hour of talk-time after just one hour of exposure to the sun.
The major problem with a solar battery charging is the fact that the sun moves continually, and my practical experience continues to be that you need to move the solar charger every couple of minutes to help keep it under the sun. It goes without saying that solar chargers for cellphones will be best for those who spend lots of time out in the open and cannot easily find a power source. Backpackers, fishermen, cyclists and other outdoor types will probably be the early adopters.
If you live in Britain or don’t spent too much time out of doors, you’re probably better sticking to the wall plug. The most effective solar cellular phone chargers available on the market take a long time to charge—a one-hour charge will give you just enough to give you five or ten minutes’ call time. It will take up to ten hours to obtain a full charge.
The Wysips development is particularly interesting in that it gives the opportunity to charge the cell phone from artificial light. The phone could be charged as light falls on the display screen, thus topping up power continuously as the phone remains inactive.
It is much more encouraging than previous initiatives to produce solar chargers for smartphones, for example Samsung’s Blue Earth mobile¹, which included a solar charger on the back. A few months ago Apple were awarded a patent² for a method to charge small units using solar powered energy, indicating that the company consider solar energy worth exploring.
The solar efficiency of Wysips’ charger is less than ten percent of that of the most effective solar panels in general use. But that is a lot better than the 0% currently offered by smartphones. The additional power gained from a Wysips solar charger could allow cellphone designers to design slimmer batteries for their devices, or empower faster, better devices with satisfactory battery lives.
The author: Sofia Sheppard writes for the Solar Charger blog which she uses to discuss the latest deveopments in solar battery chargers for small items