Being the proud owner of a Citizen Eco-Drive solar-powered wristwatch, I just had to try the K760.
This is a totally standard, Bluetooth-connected Mac-layout keyboard. It’s very similar to Apple’s own stock keyboard but for one glaring difference: the K760 has a 27.5 x 3.5cm solar panel along the top edge.
It worked fine for us with a Macbook Pro, iPad 2 and iPhone 4. In fact, a nice little feature allows you to pair three different devices, and assign each one to a shortcut key for quick switching. If you’re working with both your MacBook and iPad, for instance, this lets you easily use the one keyboard for both.
The keyboard charges from ambient light, including artificial lighting, not just direct sunlight. Once fully charged (this takes an unspecified time), Logitech claims it will operate for up to three months in total darkness.
We didn’t have three months, but we had no power issues despite using the keyboard exclusively indoors. It worked straight out of the box, day and night, for the two weeks I used it as my primary keyboard at home.
My only complaint is that, for $170, a simple solar panel slapped across the top seems pretty basic. The solar panel in my watch is the black watch-face. If Logitech could have found a way to utilise the dead space between the K760’s keys as the solar panel, the panel itself could have been almost 100% larger than it is now, while reducing the overall keyboard size.