Unless, of course, you have your own solar panel with you. There are plenty of compact solar panels from reputable manufacturers that you can plug directly into your mobile phones, cameras, fans, or laptops. But if you need a solar panel that can also work with your power tool system, you might want to take a look at Ryobi. One of the brand's many backpack-sized offerings, Ryobi now offers two foldable solar panels, one 14-watt ($79) and the other 21-watt ($99). Both options share a lot of core features, such as USB-A and USB-C output ports, compatibility with Ryobi power sources, and multiple usage options.