The brim of the hat contains little solar panels, so that as you wear it, it will charge your phone or tablet ... as well as pretty much anything that can connect to a USB port, it contains ...

Modern solar panels made from silicon-based photovoltaics just got some competition. Oxford University has developed a new technology using perovskites, which are more flexible and efficient.

Read more: Battery Brands Ranked From Worst To Best To understand how a solar panel phone charger works, you really just need ...