Mother nature and I together couldn't kill these panels.
Solar power is cool for so many reasons. It's clean, cheap and (effectively) infinitely renewable. But solar panel technology has only recently reached the sweet spot of efficiency, cost and durability needed to make it useful for normal consumers. This evolution in technology has revealed a great sleeping market for solar energy.
Worldwide adoption of solar installations increased 120% last year. In 2011, worldwide solar production will leap from 40 gigawatts to 66.2 gigawatts. By 2015, global investment in solar panels could break 90 billion dollars. There's money in solar these days, and one company making a spirited grab for that cash is Goal Zero.
They focus mainly on consumer solar solutions. I've spent the last month testing their Sherpa 50 Adventure Kit. With some minor exceptions on cloudy days, it's allowed me to take my smartphone off the power grid and taken literally all the abuse I can throw at it.
The panels are 13.5 watt, and the battery stores 50 watts. In practice, that's about two hours of juice for my laptop and about thirty hours of in-use time on my HTC Evo smartphone.
Goal Zero claims the battery takes about four hours of sunlight to charge from dead. On a bright, sunny day, it takes me a good five to six hours to get a complete charge. Most winter days, I ended with 60%. When it snowed, I managed to pull down between 20-40% of a full charge, per day. Here in North Texas, I end the day with a full charge more often than not. In my Barcelona hostel, I was lucky to get 20% though.
First off, let's be clear about what these chargers are not. They will not keep your laptop and speakers and tablet and smartphone all charged on a long trek through the woods. They will not replace your generator. But, depending on your location, they may be enough to keep your smartphone or tablet PC juiced up on long, multi-day hikes or in emergency situations. If you live in the Pacific Northwest or some other equally lightless region, you might want to look into one of Goal Zero's 27 watt panels instead.
I've found that the best location for these panels is up on the roof. I can access mine with the aid of a chair. If it takes more effort for you to get your panels up there, I'd suggest securing them somehow and just leaving them up there. Take the battery in every night and you'll be good to go.
The Sherpa 50 impressed me most with its durability. The first test came during a good old fashioned Texas winter storm. I left the panels out on my roof for several hours while it stormed and thrashed outside. When I took them in later that night, the panels were soaked thorough, and the battery was covered in beaded water.
A few nights later, a cold front blew in. This gave me the rare (in Texas) opportunity to test my Sherpa 50 in snowy, sub-freezing weather. I was unable to get the panels to stick to the roof once it iced over, so I used the barbecue grill as a makeshift solar stand. The panels froze to the grill roof every morning, but I never noticed any reduced performance as a result.
After a few days of snow, it thawed. I had handful of good days, the ice melted on my roof, and then another cold front blew in. I was away from home at the time, so my panels were left up on the roof for the duration of the storm. This greeted me upon my return:
Again, neither panels nor battery seemed adversely effected in any way.
- +Incredibly Tough
- +Easy to set up
- +Panels require very little space to store
- +Reasonably efficient for reliable daily use
- +Looks fantastic
- -Battery and inverter take up a lot of backpack space.
- -Poor performance in overcast conditions.
- -Price ($449.95) may turn some users away.
Goal Zero's Sherpa 50 Power Kit is ideal for anyone looking to spend an extended period of time away from outlets. In most summer / spring conditions, it could keep a smartphone or tablet running on even moderate to heavy use. The panels secure easily to backpacks and car roofs and can take one hell of a beating. You'll need to budget extra pack space for the battery and inverter though.