Wireless headphones are perpetually are held by their batteries. JBL, one of the world’s most favorite head phone manufacturers believes it has an alternative, though, and it's asking for your help to make it a reality. The Harman brand is crowdfunding Reflect Eternal over-ear headphones whose solar power theoretically gives you "virtually unlimited" listening.
Even if the conditions aren't nearly as favorable (say, winter), there's a good chance you won't have to plug in. There is a backup, of course -- you can plug the headphones in through USB and get two hours of playback in 15 minutes. These are otherwise garden variety headphones. They pack 40mm drivers with a 20Hz to 20kHz frequency response range, hands-free calling, a mode to amplify ambient audio, multi-device pairing and control over your voice assistant of choice. They're even IPX4-rated, so they can endure some rain or gym sweat.
JBL and Exeger are using the crowdfunding to gauge feedback and tweak the design, so there's a possibility that complaints you have now might be addressed by the time you can start listening. The product is all set to hit the market by 2020. This will be the first ever headphones which will have a solar panel to charge it, and it will also play an important role in power consumption.