Hi Friends,

Even as I launch this today ( my 80th Birthday ), I realize that there is yet so much to say and do. There is just no time to look back, no time to wonder,"Will anyone read these pages?"

With regards,
Hemen Parekh
27 June 2013

Now as I approach my 90th birthday ( 27 June 2023 ) , I invite you to visit my Digital Avatar ( www.hemenparekh.ai ) – and continue chatting with me , even when I am no more here physically

Tuesday 9 July 2019

The Biggest , FREE , Desalination Plant : Sun + Sea




Economic Times carries following news :

  

Highlights :

#    Niti Aayog eyes ways to make sea water usable


#    India’s massive coastline of 7,800 km offers huge opportunity


#   Large number of desalination plants may come up on sea or on the  coast


#   Ocean energy or solar energy will be used to run these plants


#   By 2020, as many as 21 major Indian Cities will run out of water


#  India ranks second from bottom in Global Water Quality Index


#  600 Million people face high to extreme water stress


#  84 % rural homes do not have access to piped water 
 

#  NITI Aayog plan : Floating  desalination plants in marine waters


#   Supplying desalinated water to population centres via a network of pipelines


#  NITI Aayog’s plan is also energy efficient as it seeks to use Solar Energy or Ocean Energy for the project

  
=========================================================

CONCERNS  &  QUESTIONS  :


#  Harnessing Sun energy for desalination is an idea borrowed from Mother Nature . 24x365 , our Sun is doing just
    that – evaporating salty sea water to form clouds full of clean / drinkable water . These clouds rain over the
    remotest corners of our land,

-       without needing any infrastructure of expensive pipe-lines , pouring BILLIONS of tons of drinkable water

      and do it for FREE


   Our tragedy is that we have failed miserably as far as storing / harvesting those heavenly deluge of AMRUT !


    
#   I believe, almost 90 % of the rain water flows back into the sea . Of the balance 10 % that stays on land , 90
     % flows underground ! 


So, you can calculate how much rain water, we finally manage to store in ponds / lakes
     ( which we succeed in polluting ! )



#  Can human-manufactured plants floating on sea , ever equal the Scale / Capacity / Energy-efficiency of this
    Natural Cycle ? ( even if we chose to ignore the no of years it will take to build such plants ? )



    I found some answer here :

===================================================================



Ronan McGovern
, PhD in desalination from MIT


There are two ways to think about the cost of desalination: the cost of a desalination plant, and the cost of water.


A typical large scale desalination plant produces 100,000 cubic meters of water per day. Assuming a per capita consumption of 300 liters per day, this equates to 300,000 people.


The installed cost of desalination plants is approximately $1m for every 1,000 cubic meters per day of installed capacity.


Therefore, a large scale desalination plant serving 300,000 people typically costs in the region of $100 million. The costs of infrastructure to distribute water must be added to this.


The cost of desalinated water, the majority of which is accounted for by plant capital costs and energy costs, is typically in the range of $0.5 to $3 per cubic meter of water (0.05-0.3 dollar cents per liter of water). The lower end of the scale corresponds to regions where electricity costs are low (e.g. Middle East) and the higher end to regions where electricity costs are high (e.g. Australia, where electricity is sometimes mandated to be from renewable energy).

=======================================================================

For a Perspective :

Chennai has a population of 4.9 million people ( 49 lakh )

By above estimate, Chennai would 16 / 17  desalination plants ( each capable of serving 3 lakh people )


That would cost : $ 1,700 Million ( approx. Rs 12,000 Crores ! )


I am sure that NITI Aayog report when it  gets published, will provide accurate figures of INVESTMENT ( funds ) required for 21 cities


Again, you will notice that using VERY EXPENSIVE electricity ( for desalination ) to produce drinking water is simply out of the question , if a one litre of desalinated water were to cost Rs 25 – 30 !


===========================================================

#  For a vast country like India, sea coast based desalination plants , do not seem to address the needs of rural
    people , living in desolate / semi arid areas . They need a technology which will produce ( extract ) water from
    atmosphere , using only Solar Energy ! – and no ( or very little ) need for pipelines . Above all such solar
    powered installations should be MAINTENANCE FREE




#   I urge Shri Gajanan Shekhawatji ( Minister for Jal Shakti ) , to seriously consider :


     Water above our heads



===============================================================

10  July  2019

Rsvp :  hcp@RecruitGuru,com

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