PEARL offer a solar panel that weighs less than 1 kg and is about the size of a book when it is folded together - but is supposedly able to deliver 28 watts when folded open. You are supposed to be able to attach it to your backpack or bike or use it while you are camping, in order to use the sun's energy to charge your phone or power bank. We took the "on-the-go" panel with us on our bike tour from Berlin to Poland to see how well it works in practice.https://www.notebookcheck.net/PEARL-Revolt-28-watt-foldable-solar-panel-review-Perfect-for-bike-trips-hiking-and-co.719254.0.html
These are massively behind the efficiency of modern rooftop solar panels. You can get 500W from a panel with area not much larger than this. Maybe if it were 100W at that price it would be a nice investment. Only cloudy days 28W will drop to a few W and you'll be carrying a paperweight.