There are already plenty of gadgets that allow people to charge their mobile devices while off the grid. Most of those products utilize solar power, while a few have gone the thermoelectric route. The HydroBee, however, generates electricity using the power of flowing water – think of it as a portable hydroelectric station.
So, first of all, why bother? Well, solar-powered chargers may work fine in direct sunlight, but can be thwarted by heavy clouds, tree shadows, or even just high latitudes. They also don't do a whole lot at night. Thermoelectric chargers, on the other hand, require you to build and maintain a fire.
The HydroBee ... well, yes, it requires you to be close to a stream or river. If you are, though, it will work in even a weak current, regardless of the weather or time of day.
The device consists of two main parts.
At its heart is a cylindrical battery pack that contains six 1.2-volt NiMH rechargeable AA batteries, an integrated USB port, and an externally-mounted impeller. This pack can be used on its own, installed over the end of a faucet or hose. Whenever water comes out of that faucet and runs through the center of the pack, it causes the impeller to spin, generating power.
The battery pack is contained within the HydroBee's other main component, the stream body. This floats on the surface of a stream or river (or it can even be towed behind a boat), and is held in place by a line tied to a secure anchoring point. As water flows through the device, it spins a propeller. Once again, as with the spinning of the battery pack's impeller, this juices up the batteries.
According to HydroBee creator Burt Hamner, two hours spent in a current flowing at about 4 mph (6 km/h) should be enough to fully charge the six AAs. The battery pack can then be removed and used to charge a mobile device.
Hamner is now at the working prototype stage, and has turned to Kickstarter in order to raise production funds. A pledge of US$78 will get you the battery pack and stream body, when and if they're ready to go – the estimated retail price is $98.
Other portable hydroelectric generators do already exist, although most that we've seen are significantly larger than the HyroBee (which would itself be rather awkward to stuff into a backpack) and range in price between the hundreds and thousands of dollars.
More information is available in the pitch video below.