CAN DESALINATION AND CLEAN ENERGY COMBINED HELP TO ALLEVIATE GLOBAL WATER SCARCITY?

By Aditya Sood and Vladimir Smakhtin

International Water Management InstituteColombo, Sri Lanka

Water Stress Indicator – ratio of water withdrawn to water available after environmental needs are satisfied. Red = tapping into environmental needsAFR - 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

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

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

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 - hydrocarbonsRenewable - 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

DESALINATION IS STILL EXPENSIVE!!

Cost of Desalination with different energy sources

(Source: Karagiannis and Soldatos, 2008)

BUT THE COSTS ARE FALLING RAPIDLY

THE BIGGEST COST FACTOR IS ENERGY

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

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

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.

LEARNING CURVES

• PROGRESS RATIO• LEARNING RATE

ln(Ct) = ln(C0) + β * ln(nt)

WhereCt is expected cost at nt cumulative production levelC0 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

LEARNING CURVES FOR PHOTOVOLTAIC TECHNOLOGY

Source: Breyer et al., 2010

LEARNING CURVES FOR DESALINATION TECHNOLOGY(WITHOUT ENERGY COMPONENT)

1975

2010

All cost values are in 2010 USD Progress Ratio: 0.71Learning Curve: 29%

PROJECTING FUTURE PRICE OF WATER

Based on 180 cities data collected from http://www.globalwaterintel.com/tariff-survey/

PROJECTING FUTURE ENERGY (NON-THERMAL) TRENDS IN DESALINATION

Past Trends

Projected Trends

PREDICTING FUTURE COST PROPORTIONS IN DESALINATIONProjected Water

Tariff

MINUS

TransportationCost

($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

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

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

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.

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