Minimalist Backcountry Solar Panel Setup
Here's a fun one for you. I spent some time this summer working out what the "minimalist" solar panel setup could be on a backcountry bikepacking adventure. You're familiar with the tradeoffs, weight / power / durability / weather proof / etc. What I learned from this little experiment is that solar certainly has a place, but the tradeoffs really put it squarely in the "touring" category, and even there, within a subset of touring that I'll call "siesta touring". That's when you take a break in the middle of the day to dry your tent from the night before and wisely use the time not to catch up on your social media or work email, but instead, to take a nap.
This interesting little combo has a small space claim (13.5cm x 11cm each, and you can fit them face to face in your bag) and it weighs out at 165g (add another 25g if you care to use the USB connector). In full, un-shaded mid-day Summer sun produces 4.7v and .5A. On a hazy day, it goes down to 4.6v and .3A. And if the sun goes behind the clouds or worse, if you're in the shade, you've got nothing. Most of my rides take me through a range of shade and sun, so this setup is mostly for use during the aforementioned "siesta" phase of your day - when you're stopped and have the time to orient them exactly at the sun and minimize any potential for shadiness.
The output here is at the minimum output level for a dynamo, that's why I'm calling it the "minimalist" solar setup. This listing includes two solar panels, one "y" connector that links the two together, one micro-USB connector, and one USB connector. The USB connector holds the voltage at or below 5V and allows you to charge items that don't have a micro-USB connector. The micro-USB allows voltage to fluctuate with the output of the panels (they're each rated at 7v, 2.4W, but in my testing, I've never seen that sort of output, you might if you live on the equator or on top of a mountain somewhere).
Because we were going for the minimalist configuration, it's going to take you some time to charge your devices with this setup. Imagine something simple, like a Garmin inReach Mini satellite communicator, the sort of safety device that you'd be taking with you on an adventure. It has a battery with 1,250mAh and has a micro-USB port for charging. If the battery was completely dead, it would take you about 3 - 4 hours to charge the device if the conditions were perfect. A long siesta but if your inReach were dead, I think you'd be feeling pretty awesome that you brought some panels along.