The theme of this year’s UN World Water Day is “Water and Energy.” Water is required in nearly all forms of energy production, and likewise, energy is needed at all stages of water extraction, treatment, and distribution. Not surprisingly, places that lack clean water are often without consistent electricity as well.
For a simple system that at least partially addresses both needs, students at the Technological University of Mexico (UNITEC) have designed a microturbine that purifies rainwater, IEEE Spectrum reports.
Their device -- which they call Pluvia -- is similar to that of hydroelectric dams, which use water to rotate a microturbine and generate electricity. Here, rainwater can be collected by funneling it into a gutter on the rooftop (pictured) or by adding sheeting to simulate a slope, routing the water in one direction.
The water passes through the first filter, which is specifically designed to clean rain that falls during the first two weeks of the wet season (since it’s higher in acidity, soil, and contaminants). Then it’s stored in a tank.
The water is flowed past the small turbine, and with the help of a pump, enough water pressure is exerted to drive the microturbine, generating some electricity.
When the microturbine turns, the rechargeable battery is loaded. The cylindrical power generator is only about 10 inches high and two inches wide.
After passing through the turbine, the water proceeds through a charcoal filter to remove smells, flavors, colors, and other contaminants.
"With this latest filter the liquid is equal to or cleaner than the water in the network supply system of Mexico City," says Omar Enrique Leyva Coca, who developed the project with Romel Brown and Gustavo Rivero Velázquez. They’ve already tested it in a community in Iztapalapa, Mexico City.
While the device does gain back some of the power needed to purify water, the pump requires more energy than the turbine can output. Right now it’s only possible to recharge 12-volt batteries, which is sufficient to power lights, but not an entire home. They’re trying to increase both generation and storage capacity, IEEE explains, which would allow the system to power the pump and maybe even small homes in the area.
These microturbines are typically used as smaller versions of hydroelectric dams to generate bits of electricity from streams with relatively low flow rates. IEEE explains:
That application, of course, only works in more rural areas. Those areas are often energy-poor, meaning such small off-grid systems are a great idea, but urban areas often are saddled by both energy and water poverty. Harnessing any bit of water and power that comes through a place like Mexico City, or any number of other large cities around the world, could eventually be a revolutionary idea if the devices are cheap to build and distribute.
Janet Fang has written for Nature, Discover and the Point Reyes Light. She is currently a lab technician at Lamont-Doherty Earth Observatory. She holds degrees from the University of California, Berkeley and Columbia University. She is based in New York.
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She writes for SmartPlanet and is not an employee of CBS.
I thought of micro turbines for generating electricity in gutters and downspouts as well as in rainwater collection tanks to capture energy when using water about a decade or so ago, but the problem is size and cost along with demand.
Der Zeitgeist and William: Way to take ingenuity and creativity and stomp it into the ground. And you wonder why so many people just don't give a crap about going green and respecting the Earth. Why should they when what they try to do is never right to you? How about you come down off your high horses long enough to praise the attempt? Too long a climb?
More practical than small scale hydro due the the tendency to generate a head by nature, but still dictated by the laws of physics and not cost effective by any means, when you break it down.
This is just one small example of the incredible small-sized, local, creative improvisation and creativity one sees on Mexico. People there are very good at thinking up ingenious workarounds because they have always had to.
Stupidest article I have read in a while. She even says that it is a negative energy output, grossly conflicting with the title. Pretty sad, from a technical standpoint, and only a small step up from magic elixir. If that gutter in the photo is supplying the water, that turbine doesn't stand a chance!
Clearly devised and endorsed by people who have had little to no exposure to the real-world life of mechanical and electrical components in the open environment, where moisture, dirt, pollution, UV exposure, temperature extremes and corrosion accelerate entropy. It's truly ironic that the writer/editor used a picture of a deteriorating roof line and rain gutter as the mood setter for this article describing a device that doesn't even generate enough energy to perform the end objective.
Silly, deceptively miss-worded, technically absurd and meaningless article. The micro turbine has nothing to do with purifying the water. Worse the entire concept has a negative energy out put. Meaning to have the micro turbine takes more energy than without it. Gravity filtering of rain water has been around forever and has no need for either pumps or micro turbines if properly designed.
Read the article! This is supposed to be for a place that 1) lacks clean water and 2) without electricity. And yet this device REQUIRES more power than it produces to work. Where does the power come from? Is it too much to ask for the author to be truthful in the article title? It is only slightly removed from a perpetual motion machine. (generator powering a pump that turns the generator)
Have you ever cleaned out a gutter? You are going to send that water through a MICRO turbine. Small turbine, small tolerances. Any filter that will clean gutter water up clean enough to run though the turbine without gumming it up will clog up quickly and require replacement or cleaning.
If an idea is good, it will flourish despite criticism. If an idea is stupid, covering it up in a green wrapper won't help it.
@operator2001 Yes, it's not a practical system in its present form, but remember, we're talking about rain water. It starts out a lot higher up, so all you need is an elevated collection system to get as much gravity as you need. Now how about a contest for efficient structures built out of materials that are currently going to waste, maybe used CDs, the same way students compete to build sturdy structures out of toothpicks.