At less than $50, this little dual USB port solar device is an affordable option for a clean, efficient portable charging solution.
You may not be able to install a full solar panel array on your house, but you can pick up a solar charger without breaking the bank, and then keep your smartphone, tablet, or other mobile gadgets topped off with clean renewable energy. The improvements in solar technology over the last few years have led to massive price reductions in mobile charging devices, and now, instead of being a marginal (and expensive) portable energy solution, they're rapidly becoming a must-have for anyone who spends time off the grid or who wants their gizmos to be powered with renewable energy.
The Aukey 20W solar charger is a reliable and effective solution for charging mobile devices, as it offers efficient SunPower solar cells, dual USB ports (delivering 5V, at 1A and 2.1A), a lightweight form factor, and rugged portability, all for about $50. This device measures 12" × 6.88" × 1.18" when folded (roughly the size of a legal pad), and then unfolds to about 20" long to reveal three sections of solar cells, laminated in waterproof PET and all wrapped in a rugged fabric.
The weight of this 20W charger is just under two pounds, and while the sections of solar cells aren't necessarily flexible, in the sense that they can be folded at will, they aren't rigid like the previous generation of solar chargers were. This charger isn't fully waterproof, as the USB ports on the rear aren't safe from immersion in water, but the solar cells themselves are encased in plastic and nylon canvas, so as long as the devices being charged are out of direct exposure to water, the charger itself won't get damaged by mild weather (and of course, you're not going to get a great solar charge on overcast rainy days anyway).
The back of the charger features a mesh zippered pocket for holding devices while charging, as well as any cords, and is where the dual USB charging ports are mounted. These are all pretty standard features for portable solar chargers, but one aspect of the Aukey that seems to be a thoughtful design feature is the addition of two fold-out stands that can help keep the panels pointed directly at the sun when in use. These aren't perfect, by any means, but it is a feature that could be of help in situations where hanging it or laying it out isn't the best choice. It also includes a central grommet and loops on each corner for hanging it in the sun both while in use, or for storage.
I recently spent some time using the Aukey 20W solar charger to keep my phone battery topped off, as well as to charge a few battery packs that I own, and I was pleased with the speed of charge (comparable to a standard wall charger, at least here in sunny New Mexico), while the fold-out stands made it fairly simple to prop up perpendicular to the sun. The stitching, fabric, and components (mesh pocket, zipper, velcro closure) were all of good quality, and this charger seemed to me to be a great value for the price. The only thing I'd add to it, if I were to recommend this to a friend, is an external battery pack, which would allow for charging devices after dark (use the solar panel to charge the battery during the day, then use the battery to charge mobile devices later).
[Disclosure: I received a review unit of this device, but all opinions, errors, or omissions in this post are mine alone.]