Dehumidification to solve the third world drought problem

[vernonn4styv]

Hi, I am new to this site, i am not a brain box nor am i studying for any qualifications.
I wonder why the worlds drought problem could not be solved by massive dehumidifiers to create water for crops and filtered for drinking.
So far i see no problem why this cannot be done using solar energy to charge batteries by day and produce water in the nights?
Someone told me that it is possible in places where the air is damp but will not work in arrid locations, Would africa be considered as arrid?
Does evenings hold more moisture and could this system work in places like Africa?
It is my intention to eventually be able to set this project up in a location where water is greatly needed, this will take place on behalf of a charity and all the help i can get to solve these problems would be greatly recieved. Regards Vernon.

 

[mgb_phys]

If it is too dry to rain then it is likley to be to dry to extract significant water.
There are schemes to trap water from the air in the early morning using fences made of plastic filaments - high tech versions of the shrubs that used to trap water naturally

 

[russ_watters]

Pulling moisture from the air is simply a matter of dropping that air below the dew point. What that dew point is is completely climate dependent. Where I live, in the northeastern US, the dew point runs around 60-75F for 8-10 months of the year and drops down to 10-20F in the winter (with a month on either end of high variability). So in summer, it is easy to extract moisture, in winter, it is essentially impossible (water vapor doesn't liquify, it freezes directly on a coil when it is that cold).

 

[brewnog]

Africa is a big place. The areas which suffer drought tend not to have much moisture in the air anyway.