SolSol's baseball hat can charge your phone using solar power
 

Solar technology is still far from becoming ordinary, but we're seeing more and more of it make its way to consumer products. And now that includes hats. SolSol, a startup from Los Angeles, made a baseball cap that has a small solar panel built into...

https://www.engadget.com/2017/03/13/solsol-solar-hat/