British design student Bradley Brister has always been a keen camper and hiker.
And the more time he spends outside, the more he's noticed something - people use a lot of batteries to keep their tech charged in the great outdoors.
Now Bradley has decided to do something about it.
As part of his his final-year project for his Product Design Engineering degree at Brunel University, Bradley has created a prototype solar backpack that can put power back into devices without having to plug into the mains.
See how it works in the video above.