By Aditya Sood and Vladimir Smakhtin. Presented at the "Water in the Anthropocene: Challenges for Science and Governance. Indicators, Thresholds and Uncertainties of the Global Water System" conference in Bonn, Germany May 2013.

1. CAN DESALINATION AND CLEAN ENERGY COMBINED HELP
TO ALLEVIATE GLOBAL WATER SCARCITY?
By
Aditya Sood and Vladimir Smakhtin
International Water Management Institute
Colombo, Sri Lanka

2. Water Stress Indicator – ratio of water withdrawn to water available after
environmental needs are satisfied. Red = tapping into environmental needs
AFR - sub-Saharan Africa, MENA - Middle East and North Africa, ECA - Eastern Europe and Central Asia, SAS - South Asia,
EAP - East Asia and the Pacific, LAC - Latin America and the Caribbean, OECD - Organization for Economic Co-operation
and Development, and ROW – Rest of the World Source - IWMI
GLOBAL WATER SCARCITY:
Withdrawals and Environment

3. sea water
freshwater
IS DESALINATION THE ANSWER?
COASTAL POPULATION
Cities with population of one million and greaterCities with population of five million and greater
More than 40% of the global
population lives with in 100 Km
of the coast

4. DESALINATION TRENDS
Top 10 countries (Top 3 – Saudi
Arabia, USA, UAE);
Either where energy is inexpensive, or
country is wealthy, or no water, or a
combination
Source: http://www.desaldata.com/
Growth of Cumulative global
capacity of desalinated water

5. DESALINATION IN A NUTSHELL
Desalination – is a process that produces freshwater from sea water or
brackish water
Technology
Thermal – phase change of water
Electromechanical - no phase change;
Energy Source
Conventional - hydrocarbons
Renewable - solar or wind
3 Dominant Technologies*:
Multi-stage flash (MSF) distillation – 27% of total desalinated water.
Multi-effect distillation (MED) - 8% of total desalinated water.
Reverse osmosis (RO) – 60% of total; Membrane based
*Source: IEA-ETSAP and IRENA, 2012

6. DESALINATION IS STILL EXPENSIVE!!
Cost of Desalination with different energy sources
(Source: Karagiannis and Soldatos, 2008)

7. BUT THE COSTS ARE FALLING RAPIDLY

8. THE BIGGEST COST FACTOR IS ENERGY

9. IS RENEWABLE ENERGY THE ANSWER?
Cost of energy in 2005 US$
Source: NREL Energy Analysis Office (www.nrel.gov/analysis/docs/cost_curves_2005.ppt)
Source: 2009 Renewable Energy Data
Book, US Department of Energy

10. RENEWABLE ENERGY DESALINATION
1 % of current Global Capacity
Solar
Concentrated Solar Power
• Concentrated Solar Power
• Photovoltaic
Wind
Thermal
based
Desalination
Membrane
based
Desalination
Dominant renewable desalination process: RO (62%)
Dominant renewable energy source: PV (43%) Source: IEA-ETSAP and IRENA, 2012

11. SCENARIO DEVELOPMENT
World divided into 7 regions
Globally, about 33% of the world’s population lives within 100 km of the coast:
AFR: 18% ECA: 17% SAS: 24% MENA: 37%
EAP: 38% LAC: 45% OECD: 50%
Only consider demand for industrial and domestic use:
Willingness to Pay information for these consumers.
Using 2050 as the scenario timeframe – compare at what production the price of desalination
can match willingness to pay.

12. LEARNING CURVES
• PROGRESS RATIO
• LEARNING RATE
ln(Ct) = ln(C0) + β * ln(nt)
Where
Ct is expected cost at nt cumulative production level
C0 is known cost of a product at initial phase (i.e., nt = 1) and
has same unit as Ct;
and β is slope parameter obtained by regression

13. LEARNING CURVES FOR PHOTOVOLTAIC TECHNOLOGY
Source: Breyer et al., 2010

14. LEARNING CURVES FOR DESALINATION TECHNOLOGY
(WITHOUT ENERGY COMPONENT)
1975
2010
All cost values are in 2010 USD Progress Ratio: 0.71
Learning Curve: 29%

15. PROJECTING FUTURE PRICE OF WATER
Based on 180 cities data collected from
http://www.globalwaterintel.com/tariff-survey/

16. PROJECTING FUTURE ENERGY (NON-THERMAL)
TRENDS IN DESALINATION
Past Trends
Projected Trends

17. PREDICTING FUTURE COST PROPORTIONS IN
DESALINATIONProjected Water
Tariff
MINUS
Transportation
Cost
($0.06/m3/100Km)*
* Zhou and Tol (2004)
Total Projected Price of Water
Total Projected Cost of ElectricityTotal Projected Cost of Rest of the process
ELECTRIC ENERGY
TO TOTAL COST
RATIO

18. INCREASE IN PRODUCITON REQUIRED (IN TERMS OF
“DOUBLING”)
PV Desalination
Region 2020 2030 2040 2050 2020 2030 2040 2050
AFR 24 21 19 18 7 5 4 4
EAP 14 12 10 9 1 - - -
ECA 14 12 10 9 4 3 2 1
LAC 14 12 11 9 2 1 - -
MENA 15 14 12 11 1 < 1 - -
OECD 10 10 9 8 - - - -
SAS 25 22 20 19 8 6 5 4

19. INCREASE IN PRODUCITON REQUIRED (IN TERMS OF
ACTUAL CAPACITY)
PV
(Million MW/year)
Desalination Capacity
(Million m3/day/year)
Region 2020 2030 2040 2050 2020 2030 2040 2050
AFR 50851 4170 718 171 1154.6 214.4 72.2 31.8
EAP 70 8 2 < 1 9.7 - - -
ECA 74 8 2 < 1 159.3 31.9 10.1 3.7
LAC 66 8 2 < 1 25.9 3.4 - -
MENA 155 21 5 1 17.6 1.7 - -
OECD 5 1 1 < 1 - - - -
SAS 129657 9218 1491 343 2300.6 393.3 128.8 56.3
Current global
production: 65 million
m3/day
Current global
cumulative production:
40 GW. From 1992, grew
at a rate of 2.2 GW/year

20. CONCLUSIONS
 Developed learning curve for desalination technology by separating energy component.
 Looked at the production levels of desalination and PV technology, at which desalination
can become a viable option.
 If energy is not a constraint, desalination will become viable option by 2030 in most of the
regions of the world.
 Even with PV energy, desalination is feasible with minimal growth in most of the region of
the world. For feasibility in sub Saharan Africa and South Asia, growth of roughly 170 and
350 MW/year new production required.
 This will ease water scarcity in the urban areas and free up water for the environmental
flow regulations, also reduce pressure on agriculture.
 Environmental issues of disposing off brine and other chemicals used in the process are
relevant and not considered here. These concerns (and cost) need to be addressed.

21. THANK YOU!
Acknowledgements:
-CGIAR Research Program on Climate Change, Agriculture and
Food Security (CCAFS) for providing funds to carry out this research
study.
-Most of the analysis was carried out using data provided by
Global Water Intelligence