You knew someone would do this eventually. They’ve already put water into backpacks (with a handy little over the
shoulder straw to boot), and now you will be able to charge your ipod by one. Several companies have developed solar
backpacks, backpacks essentially embedded with photovoltaic cells that convert the sun’s energy into electricity.
Clear Blue Hawaii offers the Blue Sun Solarpac ($260, battery not
included) and another company called Voltaic Systems (guys, you might have
to change that. Sounds very geeky. Maybe Ray Walk, or SunStride…call my attorney if you like these names ;-))…wait,
where was I? Oh yeah, Voltaic Systems offers the Voltaic Backpack ($229 battery included).
So both packs operate with an internal lithium battery; the Blue Sun uses a $50 or $150 lithium-ion (the more
expensive battery stores more electricity) that put out up to 12 volts, while the Voltaic’s included battery puts out
3.5 to 7.2 volts.
The Blue Sun sounds like the better bet since the solar panel is said to be higher-quality and the $50 battery will
pretty much charge all the hand held devices (GPS, cell phone, iPod, Gameboy) you might bring with you into the
wilderness. While I have not yet tested either of these packs, I do see one drawback right off the bat: their size.
They packs would work nicely for day trips or overnight trips, but you would likely need a larger pack for week-long
wilderness expeditions, and right now neither company makes a pack that fits the bill. But stay tuned.