Global warming brings many water
problems. One way around them is to use desalination. Another is to
obtain water from air! Several products are in development or are on
the market already. You watch - this trend will become a tsunami.
Global warming causes water shortages
through droughts and disappearing glaciers. It also causes polluted
water sources when there are floods, such as in the aftermath of
Hurricane Katrina in New Orleans.
Indeed several reports on the impacts
of global warming suggest the possibility of wars between nations
over water.
So there is a great and growing need to
alleviate water shortages and for clean drinking water.
There are several approaches to
harvesting humidity in the air around us. Of course the first is to
minimise the effects of global warming through going to the causes.
Reducing greenhouse gas emissions, and to "reduce, re-use and
recycle" are primary strategies.
Next, there are various technologies
that can help. These include
*Desalination through distillation
*Condensation
*Water absorption by salt
Desalination is now widely used but
water from air technology is the next trend.
Condensation
Dr Max Whisson has been called the
Water And Wind Wizard of Oz. He has patented the "Whisson
Windmill", or "Water Harvester", as he prefers to call
it. It harvests water from air.
How?
Well, Dr Whisson was inspired by a
little African beetle which collects the early morning's condensed
water from its own body. From that observation he developed his
windmill that produces water from air.
As Dr Whisson has put it: "The
amount of water available in the air is for all forseeable practical
purposes unlimited. The bottom 1 kilometre (in the atmosphere) alone
contains about 1.000,000,000,000,000 litres of water and that is
turned over every few hours. The "Whisson Windmill" or Max
Water From Air device will make it possible to get adequate water
anywhere at any time, drought or no drought."
The water you see collecting on the
ground under your car's airconditioner is an example of the same
condensation process that Whisson uses.
The Whisson windmill is essentially a
wind turbine which is connected to a refrigeration compressor. A
refrigerant cools the blades of the wind turbine, after which it is
returned to a compressor. The "free" energy from wind
drives the cooled blades of the turbine and water is then condensed
from the ambient air. This water is then collected.
This remarkable invention is under
development with the University of Western Australia.
Similar to Whisson's Windmill water
from air principle the Air Water Pty Ltd's Air Water Machines also
harvest water from air by using a condensation method. Its units are
on the market now, with capacities ranging from 28 litres (7 gallons)
per day to 5000 litres per day (1321 gallons).
Water absorption by salt
This approach harvests water from air
by forcing air through a liquid lithium chloride salt solution. This
compound attracts water from the air, after which it is extracted and
filtered through table salt which acts as a natural disinfectant. The
final step is to filter this water through a carbon filter, adding
taste.
These units can make up to 1200 gallons
of drinking water per day and have been purchased by The US FESA for
emergency relief purposes.
Water from air – The Holy
Grail?
So you see there are some pretty
interesting developments under way that promise clean water. But are
these alone the answer to a sustainable future?
We cannot use technology to refreeze
disappearing glaciers or the ice caps, refill rivers, remake their
entire ecology or stop rising oceans due to global warming.
More than technology is needed for that
– useful as it is. A truly sustainable future will involve love of
our home, the Earth, and for each other. Simple as that.
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Dr Erik Leipoldt has long been
concerned about the effects of global warming. In particular he uses
his own experience of severe disability in practical approaches
towards alternate energy sources to survive and thrive in our
environmentally disabled world. See
http://www.alternate-energy-sources.com/Whisson-windmill.html
