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WORLD-GENERATION NOVEMBER/DECEMBER 2016
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PERSPECTIVE
Water shortage and desertification are
going to be the major challenges in certain
parts of the world and it is going to be the
predominant problem in the near future.
Water shortage has been observed in
California and in areas affected by the
expansion of the Sahara Desert and deserts
in other parts of the world. It has also
alarmed environmental scientists. Most of
the available water in the world is seawater
and fresh water is only a fraction.
Therefore, it is of paramount significance to
find alternative methods to desalt seawater
into freshwater for an ever increasing
human population.
Large desalination plants of a few
million gallons per day have been put up in
the Gulf region. Earlier plants were based
on thermal desalination technologies, such
as Multi Stage Flash (MSF) and Vapor
Compression (VC) distillation systems. The
total energy consumption including both
thermal and electrical amounted to more
than 150 KWh per 1000 gallons of desalted
water. The scene has changed after the
emergence of membrane based
technologies, such as Reverse Osmosis
(RO). Currently with the energy recovery
turbines/work exchangers, one can
consume only about 10 to 12 KWh per 1000
gallons of water. This amounts to only
about 2.5 $ per 1000 gallons of freshwater
from seawater. This cost varies from place
to place due to variation in the cost of
electricity. The future developments in
forward osmosis or any other promising
technology may further reduce the energy
requirement for desalting seawater or
brackish water.
Seawater desalination is appropriate in
coastal and island regions, where brackish
water desalination is important in interior
regions of the US main land, such as
Arizona, New Mexico etc, where water at
100 to 300 feet below the ground is
brackish with 3 to 4 grams of salt per liter.
However, whenever one applies
desalination technology in such interior
regions, one has to ensure zero discharge
technology failing which the concentrated
reject discharged into the ground is going
to increase the salinity of the ground water.
The hybrid Reverse Osmosis-
Electrodialysis, followed by evaporation-
crystallization is one such method to
produce fresh water and salt, so that, there
is no waste discharge to the ground.
Solar energy or renewable energy
application for desalination will further
reduce the cost of desalted fresh water.
This is due to current international cost of
solar cells standing at 25 to 30 Cents per
watt of solar cell panel as against about 1 $
in USA. Therefore, solar desalination is
much more appropriate compared to
conventional energy based desalination.
The solar seawater desalination based on
such technology may costs less than the
conventional seawater desalination
I put up the first directly connected
Solar Desalination system in 1981 in an
un-electrified village, Avania in Gujarat and
later put up a directly coupled solar
desalination system in 1986 at Tanote in the
Thar Desert in India to provide fresh
drinking water to local inhabitants and
border security forces. The water was
drawn from a well of about 300 feet deep
and it contained about 5 grams of salt in
one litre and it was desalted to provide
drinking water. This type of technology is
applicable in places like Arizona, New
Mexico, California or any interior places
with brackish water to provide safe
drinking water.
The hybrid desalination technology was
applied again for oil produced wastewater,
i.e. oil field brine in Alberta. Currently my
team has developed technologies for
treating fracwater, i.e. wastewater produced
during the extraction of natural gas and oil
produced brine i.e. wastewater produced
during oil drilling operations.
SOLAR DESALINATION
BY MAHABALA ADIGA
BACK ON CAMPUS
WITH NIGEL COCKROFT, CLASS OF 2016
World-Gen
met with Nigel Cockroft,
General Manager of JinkoSolar (US) Inc. at
the Jinko exhibit during Intersolar NA to
discuss ongoing utility and residential solar
sales in 2016. In 2015, JinkoSolar was
positioned as one of the top three solar pv
manufacturers in terms of sales volume,
with over 1000 mw shipped in the US alone.
The company has since grown past its
competitors, ranking #1 globally for modules
deployed in Q1 and Q2 of 2016. “For the
first half, we’ve shipped more modules than
any other company and continue to expect
this rate for the remainder of the year,”
Cockroft said.
Cockroft attributes these results to its
exceptional post-sales service; JinkoSolar US
Inc. continues to have an over 99.97% ontime
delivery to job sites. “We import the
modules to the ports and warehouses and
begin shipping between 40 to 60 trucks a
day to different job sites; a large utility
project would typically receive 10 to 20
trucks a day,” he explained.
Jinko scheduled appropriately during
the West Coast ports labor issues: “We were
able to keep our almost perfect record by
absorbing variable costs to provide superior
service. Obviously, we try to build that into
the overall cost and pricing expectation.”
JinkoSolar (US) Inc. has had zero power
output warranty claims since 2011. Cockroft
stated that this is due to the high
performance of the module, including its
aging properties, which should perform
better than the warranty. “All the products
coming to the US are using DuPont
material,” he underscored.
“JinkoSolar has quickly become the
brand of choice for utility-scale installations
due to our high-quality modules and
unmatched post-sale service,” he pointed
out, “I believe JinkoSolar’s 1500 volt Eagle
modules with DuPont™ Tedlar
®
backsheets
are by far the most robust in the North
American market. Offering these high
quality modules is yet another step in our
effort to provide our customers with the
best technology and proven reliable and
cost-effective products.”