'I'm always looking for the Hows and the Whys and the Whats,' said Muskrat, 'That is why I speak as I do. You've heard of Muskrat's Much-in-Little, of course?'
'No,' said the child. 'What is it?'
- The Mouse and his Child. Russell Hoban.

Go here to find out more.

Saturday, 19 April 2014

Pure Water from a Billboard

Imagine living in Lima - a city located in a part of Peru so dry it receives less than 1 inch of rainfall a year.
Yet, tantalisingly, the the humid air above you is full of moisture, if only you could get it.

The University of Engineering and Technology of Peru, in an attempt to encourage young people to pursue engineering careers, have come up with a cool idea.

A simple reverse-osmosis condenser in a billboard-sized structure has been constructed and delivers pure drinking water into 20-litre tanks.

Here is the original article.


  1. Now that is a cunning trick. I wonder how much power it uses.

  2. You really set me thinking on this one Katherine. The population of Lima is about 8.5 million. That's a huge water requirement even assuming they don't all shower every day. That's a huge number of billboards required. However my real question (not seeking an answer from your good self) is where the water from the wells comes from given the paucity of rainfall.

    PS I'm not sure how I missed your last two posts but I'm now up to date.

  3. I've always believed that one can collect water from two sheets of transparent plastic. One digs a small indentation which is lined with the first piece, then the second piece is stretched over the top. Condensation 'should' appear and drip into the bottom. No idea if this actually works.

    1. Yes it does. I think they are called solar stills.

    2. Sounds just like Bear Grills to me !!

  4. Nothing is perfect. The carbon dioxide footprint of this water production is extremely high. See earlier post, concerning carbon dioxide.
    As with all types of water production in area’s where there is no water, it costs an enormous amount of energy. Don’t let the “reversed osmosis” mislead you. It is only for purification purposes. There is no big trick unfortunately!

  5. Ah, well, it was a nice idea.