The failed solar Android products remind me of the failed fingerprint sensor smartphones. Motorola built a fingerprint scanner into its first Atrix phone. The Toshiba Portege G900 and G500 phones had them, too. Hitachi's Japan-only W51H included a fingerprint reader. And there were others. None of them were popular with customers.
All these efforts failed for the same reason the Android solar phones failed: The technology wasn't ready for prime time. The implementations were horribly ugly.
I'm hoping that Apple will eventually do for solar phones what it did for fingerprint readers: Wait for the right technology, then integrate it into a phone in a way doesn't destroy the aesthetics of the device.
Still, there are some interesting Android projects. Take the Earl, for example. It's a $300 solar-powered Android tablet for hikers and campers. It's being self-crowd-funded and has far exceeded its fundraising goals.
Unlike most solar phones and tablets, which seek merely to extend battery life a little bit, the Earl is designed to run entirely on solar power, with no need to ever be plugged into an outlet. It achieves this feat by using a low-energy 1024x768 black-and-white E-ink touchscreen. Five hours of charging gives you 20 hours of use, according to the company.
The tablet has various features that are useful for survival in the great outdoors, including GPS, a thermometer, humidity and barometric pressure sensors, and a compass. It also has a built-in walkie-talkie feature and a radio that can pick up AM, FM and shortwave signals.
Why solar fails on phones
Despite huge demand for longer battery life on smartphones, the challenges to achieving that with solar technology are many. There's a simple reason for that: Smartphones are small; they have only a tiny bit of surface area for collecting light. On top of that, they're energy hogs, with power-gobbling components such as touchscreens, various types of sensors and powerful processors.
You'll note that the Earl device achieves solar self-sufficiency with a tablet-size surface area and a screen that's about the same quality as the ones on older Kindle models.
Smartphones can't be big enough and low-energy enough to viably use solar power and still succeed in the market as popular gadgets. That's especially true because apps are increasingly power- and resource-hungry. Many apps constantly ping for connectivity and location data and make other energy-intensive requests. Games tax graphics and processing hardware.
Still, there's hope. UCLA eggheads are working on a see-through film that functions as a solar panel. This would theoretically enable touchscreens to harvest energy from light. The technology is a long way from being ready for widespread use. It can currently convert only about 7.3% of the energy it receives into usable electricity.
Sign up for CIO Asia eNewsletters.