2. Eton Soulra XL This solar-powered boombox illustrates the two chief problems of solar tech. One, it takes too damn long to charge: you have to leave the Soulra XL in full sun for five hours to get eight hours of playback. And two: it costs $150 more than a comparable non-solar product. That could buy a lot of batteries. Price: $250

3. Sharp Solar Hybrid SH6230C Cell Phone When your cell phone's battery goes out now, which happens all too quickly, you need to plug in a charging cable. Imagine how much more annoying it would be if you had to wait for a sunny day to (slowly) charge your phone. This Sharp model never reached the U.S., thank goodness. Price: Unknown

4. Voltaic Solar Backpacks Hope you've got comfortable shoes. These backpacks may be feel-good purchases, but even the Voltaic site admits it takes four to five hours in full sun to charge a phone with one of them. Once your phone is charged, you can call for a cab. Price: $199 and up

5. KudoCase It's easy to be cynical about solar power when there are products like this around. As the KudoCase site itself notes, "Sunlight is much stronger than indoor light" and will power the case better. "A lifeguard that only uses their iPad solar case a little may go weeks or months without needing a charge." Seriously? Most of us haven't gotten that much sun since we went to summer camp. And by the way, that lifeguard should stop checking his Facebook and watch the damn pool. Price: $190

6. Eton Rukus Solar The Eton Rukus lists for $100. The Eton Rukus Solar lists for $150. How much energy do you really think you'll save? No doubt you'll end up using the included AC adapter or USB port to charge this thing most of the time, anyway. Price: $150

8. Eton Mobius Eton has made a pretty attractive iPhone case here. Too bad it'll rarely be on an iPhone: most of the time the owner will leave it outside to charge in the sun while actually using his or her iPhone in a house or office. Price: $80

9. SolLight LightCap 300 Here's a solar product for people who actually spend a lot of time outdoors: hikers and campers. It's a BPA-free water bottle, a lantern that can last for eight hours, and a waterproof case for valuables (when not holding water). Also, it's not expensive. Can anyone think of a snarky comment?, because this one actually seems kind of cool. Price: $30

7. Quirky Ray Leave it to community design collective Quirky to come up with one of the few solar gadgets that looks worthwhile. Attached to a window, this thing might actually provide a decent charge. But hold off on using it in an airplane unless you want to find out who the air marshal is on your flight. The next thing you know, four 300-pounders will be pinning you down as your plane makes an unscheduled landing. Sadly, like a lot of Quirky products, the Ray isn't yet for sale, but in the meantime you can learn more about it here.

10. Solar Visor Radio Ah, good: back to the crap. It's a solar-powered radio and a visor all in one. It's a product you can only imagine wearing as a joke. It's just so damn ugly. Get one now, hipsters, and see if you can start a trend. Price: $26.50

1. Logitech Wireless Solar Keyboard K750 This is the best solar-powered tech gadget on the market and it's worthless. Why? Because most of the people who would buy it sit in dimly lit offices illuminated only by the bluish light of their monitors. That's not going to power anything. Then again, it's got favorable reviews. Maybe solar-powered keyboards are the new solar-powered calculators and we just don't know it yet. Price: $80