There are few more fundamental issues in world development than clean water. The availability of clean water and sanitation can be revolutionary; if you can assemble the infrastructure to pipe the water around, keeping it clean can be done inexpensively. But is piping and filtering the only solution?
Olivia Lum suggests not. A Singaporean who grew up in a ramshackle home in Malaysia without running water, Lum is the founder of Hyflux, a company specializing in the development of innovative water-treatment systems. Hyflux systems are in use in Singapore and China, and was just awarded $250 million to design, build, and operate Singapore's first desalination plant. It has also invented a system it calls "Dragon-fly," which pulls remarkably clean water out of the atmosphere. It's a condensation process, similar to the side-effects of running an air conditioner in a humid environment, coupled with both physical and UV filters.
Given sufficiently humid and warm air, the Dragon-fly can pull from 6.5 liters to over 24 liters of water from the air in a day, de-humidifying the surrounding air in the process. Given that the minimum required relative humidity is 45%, and functions best with humidity over 60%, the Dragon-fly is not going to be useful everywhere. But many of the regions of the world most likely to be hit hard by global warming-induced storms are already pretty humid; systems such as these could be very useful as means of guaranteeing clean water as a stop-gap while damaged infrastructure is made sanitary, as long as generators are available. And who knows? Maybe there's a market for a "pipeless" water infrastructure to match the wireless communication network.
The Dragon-fly is certainly not perfect: it's expensive and requires a serious amount of electricity to run the condenser, the UV filter, and the refrigeration unit. This is neither a device for hyperdeveloped West nor for the underdeveloped South... but it's a definite candidate for the Leapfrog Nations, those parts of the world taking advantage of new techs and new approaches to jump headfirst into the future.
I had a similar idea a while ago, then noticed a company called Vapaire doing something similar. The problem, as pointed out in the entry, is the relative technological sophistication of this solution. Think of everything that's required to make this solution work: fairly sophisticated manufacturing (or the income to support purchase of products of sophisticated manufacturing processes), electricity, and constant maintenance.
I'm curious why more low-tech approaches aren't being investigated - are they not plausible? Scalable? Or merely not profitable enough?
When I was in my college, my thermodynamics professor told me how pilots during WWII would cool their beer without a fridge. First, they'd soak a rag in gasoline, and then put both the beers and the gasoline in a bucket on the tarmack. The combination of the airflow from all the landing planes, combined with the evaporation of the gas would chill the beer quite quickly.
This was an innovative low-tech solution. It makes me wonder if we are perhaps looking to more sophisticated technology when we should be looking to less sophisticated technology to solve problems for "undeveloped" countries. After all, given the toxic problems that have been caused by our manufacturing industries and increasingly disposable technology, perhaps "leapfrogging" means doing more with less by looking back, not forward.
It makes me wonder: What could the Quakers or the druids teach us about dew harvesting that could be augmented by modern materials knowledge?
I'm sure there are situations where something like this would be way useful.
But I can't imagine it being an efficient or affordable way of producing potable water in any case where water of almost any sort -- salty, shitty, or contaminated -- is available.
Using a combination of passive solar stills and low-techy gadgets like the ceramic-pot decontaminator would probably be way more affordable.
I would posit that while this machine is no panacea, it may well have its place. Devices like this advance the discussion.
There are undoubtedly as many low-tech solutions as high to the water problem, but as I say about almost everything, "the truth is somewhere in the middle."
An (I think) even better version of this is being developed by Qinetiq in Britain--it's designed for the desert, and for off-grid locations (unlike the Hyflux which is very clearly a first-world office/home/factory device.) Qinetic's vaporator (pardon the Star Wars terminology) claims it should produce 4 liters of water per liter of diesel fuel burned. Unfortunately the Hyflux doesn't give figures for its power-effectiveness, but at 1 L/hr (the best it can do) at 600W/hr (again, its best) and what-looks-like-standard 1500W/L for diesel generators (I may be wrong on this), it'd only give you about 2.5 liters of water per liter of diesel.
On the other hand, Qinetiq's isn't for sale yet.
But as others've pointed out, a solar still is _much_ cheaper to make, and doesn't burn fuel, so if you're not living in a desert it's the way to go.
A far simpler and cheaper way to give people water is to just give em all those cheap filter straws. Mass production should be able to get the cost of the straws down to 10 cents or less each and each one can filter 50 gallons of water using your own body for all the energy needed. And water sources are almost everywhere they just arnt CLEAN.
Thats water for only .2 cents per gallon wich is a heck of alot cheaper then those ideas.