Green Heroes: From 'SunUp' to sundown this invention has your back

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.