Over the past few years, there have been a few attempts at creating a solar-based smartphone charger. The Solio Universal charger kit got high marks from CNet: “After exposing it to the sun for about 45 minutes, we got enough juice on the phone to make a 20-minute call—impressive.” Although, the review does emphasize that the charger needs to be placed in direct sunlight to work effectively. Using photovoltaic cells to power electronic devices is nothing really new; calculators, for example, have been light-powered for decades. However, their power requirements are quite meager when compared to such devices as smartphones, iPods, and other consumer electronics. But enter Cardiff, Wales-based G24 Innovations, which is working on a photovoltaic cell powerful enough to power a mobile phone using not just the Sun, but indoor light, as well. Says Business Green:

The technology, which allows small solar cells to generate energy from low level indoor light, is already operating shade and blind systems for one of the largest hotels in Las Vegas and G24i is now working on applications for wireless keyboards.

The company says it has developed a photovoltaic cell with a record high efficiency rating of 24%, and they are shooting for 40%, which they believe is possible. Light-chargeable batteries are a great idea, enabling users of these devices to reduce their overall electricity consumption but in some ways, smartphones may not be the best application. Removable, disposable batteries (and even rechargeable batteries which have a finite lifespan) are a larger problem, and it would be great if photovoltaics could go some distance toward displacing them or increasing their overall lifespans.