Answer: Wind or water.
Most off-the-grid device chargers rely on solar exposure to provide a charge. However, an unpredictable force known as the weather means that you can’t always rely on sunlight being available when your phone or camera battery needs to recharge.
That’s where the WaterLily Turbine comes in. Rather than solar, this device relies on more predictable sources of natural energy — water and wind. Just toss the wheel-shaped device into a running stream or hang it up in the wind, and plug in. Two to four hours should be enough time for an iPhone to fully charge. And you can leave it unattended while it works, so the adventuring never has to stop.