Cheap Solar Power Example
 

I bought a very cheap (£4) small USB solar panel to mount on my rear bicycle rack, does the job.

https://www.aliexpress.com/item/1005008036267839.html

It was very basic and fragile so I modded it with taped cardboard on the back with cutouts for the cable to go through and duct taped some velcro straps on. It's doing about 4W charging in bright sunlight.

Would be interesting to know what other solar solutions people are using on their bicycles....

https://cimg6.ibsrv.net/gimg/bikefor...52fa0d9c69.jpg
USB Solar Panel mounted on bicycle rack, cable going into pannier to charge phone
https://cimg9.ibsrv.net/gimg/bikefor...f44b8c4496.jpg
USB Solar Panel mounted on bicycle rack
https://cimg0.ibsrv.net/gimg/bikefor...f1f55d7f21.jpg
USB Solar Panel, modded with straps.

That looks interesting. What do you charge with it? Would 4w be sufficient to keep a Garmin GPS charged or a phone (assuming minimal use during the day)?

I have a similar panel (FlexSolar 6W). Until last year the panel was on top of my handlebar bag. Convenient - worked well.

This summer it'll have to be on the rear rack as I no longer use a handlebar bag. I am considering options. Most likely, the panel will sit on top my food bag that is lashed on top of my rear rack.

Not sure how to deal by the battery bank. For now I plan to glue a female Garmin quarter mount on the back of the panel and a male adapter to a small battery bank. Or perhaps mount a small pouch to the back of the rack.

I use a dynohub. I estimate that on fairly flat terrain, I get about 2 watts on average, more hilly get about 1 watt on average. But I am pretty obsessive on keeping my power needs to a minimum. Use a GPS while riding but the phone is off. Taillight is not a super powerful one, but still use one. I am self sufficient on bike tours for power needs.

So, if on average you can get 4 watts, that is more than adequate. But, cloudy days happen, times when your panel is pointing the wrong way are not productive, etc.

If you are curious to know more on what I do, go to this link:
https://www.bikeforums.net/touring/1...ne-2024-a.html
and skip down to the section titled: Electrics, Electrical Devices, Charging Devices, and Navigation.

It's enough to slow charge my phone (reduced power consumption) which I use with GPS to record rides, or my spare USB lights. From a quick web search it looks sufficient power to charge a garmin:

https://search.brave.com/search?q=ga...95695f6e5a84b3