Over the years we’ve seen increasing numbers of solar backpacks and messenger bags designed to keep mobile devices juiced up by harnessing energy from the sun. With the flood of tablets looking to jump on the iPad’s coattails at CES 2011, it comes as no surprise to see a solar bag specifically designed for such devices. Produced by Voltaic, the company behind a variety of solar backpacks and messenger bags including the Converter, the Spark Tablet Case’s solar panels generate 8 watts of power to provide about an hour of iPad runtime for every hour in direct sunlight.

The Spark Tablet Case includes a battery pack that holds nearly one full iPad charge. It takes eight to nine hours to charge in direct sunlight and can also be recharged from normal or high-powered USB ports or wall charger. To speed up iPad charging the bag includes a “high-power” 2A USB port in addition to a “normal” 650 mA USB port.

The bag’s solar panels are waterproof, while its 600D shell is made from recycled PET and is waterproof, lightweight and UV resistant. Including the battery and solar panels the Spark weighs two pounds (900 g) and measures 13.5" high x 10.5" wide x 1.5" deep (34 x 27 x 4 cm) with the interior mesh pocket providing room for your tablet’s various adapters and cables.

The bag can charge a range of devices via normal or high-power USB ports or via adapters for devices lacking USB charging capabilities. In addition to tablets such as the iPad and Samsung Galaxy Tab, Voltaic expects the bag will also charge upcoming tablets from Acer, Archos, ASUS, RIM and HP.

The Spark Tablet Case will also charge most mobile phones and the voltage output of the bag’s solar panels can also be adjusted from 6V to 12V to charge larger 7.4V DSLR camera batteries. However, this will require an optional battery cradle that supports the specific camera battery.

Voltaic expects to release its Spark Tablet Case in the Northern Hemisphere Spring 2011 at a price yet to be announced.