Solar power has potential but have yet to see it realized. It is really quite a shame even though possibilities are promising. The best place for solar and other alternative sources of energy to shine (no pun intended) is during disaster. I’m thinking about this today because I’ve just finished testing Solio H1000. Here’s the promise of solar power during disaster: storm passed through and power has been cut off. You’ve been using your cell phone to reach your family and friends to let them know you are ok. Of course your cell phone didn’t get fully charged because the storm hit in the middle of the night and knocked the power out before it charged. You reach over to solar powered battery recharger and plug your cell phone in. The phone starts to charge. The solar panels are converting the sunlight to power for your cell phone, and you’re up and running again. Here’s the reality. You’ve kept the solar powered recharger in your closet, so the internal battery is dead when you pull it out. The manual you read shows that it needs couple days for it to get fully charged. Having really no other option, you put it in sunny spot hoping for the best and then start to do other things for the day.
Seriously, if you look at Solio’s website at http://www.solio.com/charger/support/fao.html#Q8, it reads that it will take minimum of two days to get full charge if kept outside, in direct sunlight, and moved regularly to keep it perpendicular to the sun. I put two different solar chargers on my window at work and left them there for week. Neither charged more than quarter over the entire week. If was able to get this charger to work as advertised, I’d still need to have three since recharge my phone daily. Two would always need to be charging while charged my phone with the third finally plugged the solar chargers in to charge the battery to full charge. After the one I had was charged, I left it in the window just to keep it fully charged – which it did. I was heading out for the weekend so grabbed it. While the device has many adapters to charge cell phone, it didn’t have mine. Granted that micro-USB connector (not mini-USB) is fairly new, it is the new standard that all cellular manufacturers have agreed to build to over the next handful of years connected the charger to my phone last night when my phone was near dead. This morning, my cell phone was only 75% charged and the solar panel recharger was depleted. And I’m thoroughly disappointed. The Solio H1000 couldn’t charge in day, nor could it fully recharge my cell phone.
For my $100, I’d rather get handful of the AA-battery rechargers that work out really well and can be reloaded with AA batteries. I’ve looked at larger solar power sources for use on disaster as well. These are in the tens of thousands of dollars range and essentially impractical for the general consumer but may be well suited for a commercial use. Let’s consider system that has two 200-watt solar panels. Each panel would be a little smaller than three feet by five feet and weight about 40 pounds. Add the stand and you’re looking at 100 pound system. At peak operations, this system would generate 200 watt-hours. The lowest charger wattage for the laptops that I use is 60 watts. Those 60-watt chargers keep up with the running computer and slowly recharge the battery. My cell phone is 15 watt charger. If you don’t know how to figure this, just remember that voltage times amperage equals wattage. Look on the back of the wall charger or power supply. 120 volt charger that operates at .15 amps uses 18 watts. You can also go backwards: 150 watt light bulb at 120 volts uses .25 amps. Learn more at http://en.wikipedia.org/wiki/Watt. So a 200-watt hour solar panel system will be able to run two 60-watt computers and charge five 15 watt cell phones per optimal hour. This is rough generalization since laptop computers have their own batteries to augment the solar panel, and they may not draw the full 60 watts. Same with the cell phones. On the other hand, the solar panel probably won’t be operating in optimal conditions either. That is lot of cost and effort to setup to run very little equipment. Portable generators are usually in the 5,000 to 7,000 watt range. If you can find the fuel and vent it properly, these are the much better alternative and can power many more devices Maybe in the future, solar panels and battery storage systems will be better. Unfortunately, it just isn’t there today
——– Update on August 23, 2009 ———
Here’s timely article on CNN about solar phone chargers in Kenya:
I’d be very interested in having solar panel built into the battery on my phone. Even if it wasn’t efficient, it would be easy. The other part of the article of note is where Gathungu said until he buys one [the solar back], he’ll keep making the trek to the shopping center every Sunday afternoon after church. He wouldn’t go into further detail about his mobile phone woes, not wanting to waste his battery charge on the call. He only needs to charge it once week?