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Hydra's Solar-Hydrogen Power Makes Clean Water From Dirty at 20,000 Gallons a Day

hydra water

For the one in every eight souls around the world lacking access to pure drinking water, how about this: A solar-powered water purification system that spits out pure water, hydrogen and, just for kicks, electricity too. Could it get any better than that?

The device is called Hydra, and like its many-headed mythological namesake it truly serves a multitude of purposes: As its press release notes, "imagine a single trailer-mounted device that turns scum into over 20,000 gallons of pure water a day, stores electricity better than a battery, makes medical-grade oxygen, and runs on the sun." That's quite enough benefits from one device, thankyouverymuch.

It works on a very simple, long-understood principle: electrolysis. This is a chemical process by which water molecules are split or decomposed into their component parts, which is two atoms of hydrogen and one of oxygen for each molecule—the magic happens when you apply high voltages to electrodes suspended in water, with gas collection systems at the top of each electrode (one for each gas). In Hydra, the electricity is provided by a giant solar cell, and the gasses are stored in tanks. The next step of the complex system takes the hydrogen and uses it to drive a fuel cell (meaning the system works even when the sun isn't shining). This generates electricity, which can be used locally and also drives a water purification system.

The products are exactly what you may expect: Oxygen to help with medical problems, electricity for any number of purposes, and pure water at a phenomenal rate. The version shown in the video is just the first working prototype, but when it's productized and put on sale for $100,000, the device will be designed to be resilient and portable, with the notion that it can be deployed to difficult locations, and even be airdropped into disaster zones to aid survivors.

But how does Hydra compare with other systems out there that offer some of the same benefits? The highest profile one of these is probably Dean Kamen's Slingshot system, thanks to his celebrity and bold claims. It works on a different process (vapor compression distillation) which is, like the system behind Hydra, nothing new. What is new is Kamen's optimization of the process so it can work from pretty much any polluted water supply, uses just 2% of the energy of previous purifiers like it, and will result in a system that an supply about 1,000 liters of water per day for a $1,000 to $2,000 per-unit cost. It's powered by a Stirling engine, which needs fuel to burn—but the fuel can be almost anything, including cow dung, and the engine also supplies spare electricity.

So Slingshot does compare well to hydra, but doesn't have all of the exact same benefits, or tremendously high water through-put from a fuel-less system. Hydra's another tool that'll be of extreme importance in future emergency relief situations—though, like Slingshot, it's all about how you utilize this tech that'll really save people's lives: Drop a Hydra or a Slingshot into a disaster area, with a couple of hundred Hippo Rollers so that folk can get the water safely back home, and now you're talking real solutions.

To keep up with this news follow me, Kit Eaton, on Twitter. That QR code on the left will take your smartphone to my Twitter feed too.

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