All you need is a body of flowing water to juice up Blue Freedom, thought to be the first personal, portable hydropower plant.

Just 20 centimeters long and weighing 400 grams, the device is small enough to fit in a knapsack and is capable of charging cameras, mp3 players, razors, navigation devices, LED lamps, camping fridges, and — of course — smartphones, tablets and more.

Even if your lifestyle isn’t rustic enough to bring you to a babbling brook very often, all it takes is one hour in moving water to give it 10 hours of power for a smartphone.

Equipped with a speed charging port, it claims to transmit fast energy to your gadgets and it comes with its own rechargeable battery pack that makes it fully usable when there’s no stream nearby.

To charge Blue Freedom in the water, you simply remove the inner hydrodynamic turbine, attach it to the string on the integrated power plant, cast it off and watch it spin.