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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