Solar Energy for Application to Desalination in Tunisia: Report of a Demonstration
Project
Karim BOUROUNI, and M.T. Chaibi
Dr. Assistant Professor at ENIT
U.R.
Energétique des Bâtiments et Systèmes Solaires
NATO Advanced Research WorkshopNATO Advanced Research WorkshopNATO Advanced Research WorkshopEnhancing Security in the Middle East through Regional CooperatiEnhancing Security in the Middle East through Regional CooperatiEnhancing Security in the Middle East through Regional Cooperation on Renewable Energy on on Renewable Energy on on Renewable Energy
161616---18 January 2008, 18 January 2008, 18 January 2008, The The The London School of Economics and Political Science (LSE), London, London School of Economics and Political Science (LSE), London, London School of Economics and Political Science (LSE), London, UKUKUK
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Assistant professor at the “Industrial Engineering Department” at ENIT since september 1999
Researcher in “ R.U. Energetic of Buildings
and Solar Systems”
Engineering School relied to the university
of Tunis (Ministry of Education and Research)
1200 Students, 160 Professors, 50 Engenieers,
50 Professors Visitors
Twenty laboratories and research units
Actual Position
Ecole Nationale d'Ingénieurs de Tunis. B.P. 37 Le belvédère 1002 TUNIS. Phone: (216) 71 874 700 - Fax: (216) 71 872 729 - Info: www.enit.rnu.tnEmail :[email protected]; [email protected]
ENITENIT
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http://www.enit.rnu.tn
WATER: TREATMENT
AND DESALINATION
AUTONOMOUS
DESALINATION UNITSRENEWABLE ENERGIES
COOLING SYSTEMS
DESIGN, MODELING ANDEXPERIMENTATION OF HEAT
EXCHANGERS
Research Fields
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PlanPlanPlan
1. Problematic :
• Water situation in Tunisia
• Water Desalination projects
• Energy resources
• The Rural population
2. Water Desalination by Solar Energy in Tunisia
• Litterature Review
• Renewable Energies in Tunisia
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3. Pilots of Solar Desalination in Tunisia :
• Multiple Effect Desalination Project
• RO Project
• HD Project
4. The Demonstration Project of Ksar Ghilène
• Presentation of the village
• Project Presentation
• Some Results
5. Conclusions and Perspectives
PlanPlanPlan
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Water Situation Water Situation Water Situation
In Tunisia and Mediterranean CountriesIn Tunisia and Mediterranean CountriesIn Tunisia and Mediterranean Countries
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Tunisia Location – Water Resources
� Arid to a semi arid climate, � Lack of precipitation + variability in space and in time.
�North 1,300 mm per year (eg. The northwestern region of Tabarka) �South receive less than 100 mm of rain per year.
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Water resources availability by region
Region (Area%)
Northern(17)
Central(22)
Southern(61)
Total(100)
Surface WaterMm3/y
2185 290 225 2700
Ground WaterMm3/y
550 465 830 1845
Total Water resources Mm3/y
2735 755 1055 4545
Total over all regions, %
60 17 23 100
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0%10%20%30%40%50%60%70%
%
North Center South
Area
Waterresources
Regional distribution of potential water resources in Tunisia
0%
10%
20%
30%
40%
50%
60%
SurfaceWater
Shallow GroundWater
Deep GroundWater
58,5%
15%
26,5%
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Water resources classification according to salinity levels
TDS <1.5g/l 1.5-3g/l 3-5g/l >5g/l
24%74%Surface Water
22%19.9%Deep
20.9%39%74%Shallow
56,7%
31.7%
2%
1.4%
8.4%
Gro
und
wat
er s
ourc
e
20 40 60 80 100%
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Salinity Salinity Salinity Salinity
Region <1,5 g/l 1,5-3g/l 3-5g/l >5g/l
North 211 205 119 23 558
Center 167 191 88 35 481
South 3 500 281 75 859
Total 381 896 488 133 1898
Percentage 20,1% 47,2% 25,7% 7,0% 100,0%
Total
Underground Water according to salinity levels (in Mm3/year)
In the south only 0,35% of underground water is potable
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Algeria
Morocco
Egypt
Libya
Tunisia
0
2000
4000
6000
8000
10000
12000
1990 1995 2000 2005 2010 2015 2020 2025 2030
Water Demand (Million m3/year)
Projection of Potable Water demand in the North African Region
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Projection of Specific Water Demand in the North African Countries
14
Water Supply situation in Mediterraneancountries
Year
1985 1995 2005 2015
2000
40060080010001200
Water
Supply
Egypt
Morocco
Algeria
Tunisia
Jordan
Lybia
m3 (year/inhab)
2025
Tunisia is one of the most concerned Mediterranean countries by water deficiency
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The solution
In order to :– cover for any future deficit in water
– improve the quality of water
Desalination = Adequate solution
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Water DesalinationWater DesalinationWater Desalination
In TunisiaIn TunisiaIn Tunisia
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Desalination Process
Phase ChangeMembranes
Reverse Osmosis
Electrodialysis
MED
MSF
< 5 kWh/m3
≈15 kWh/m3
≈18 kWh/m3
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Functioning since 1984Production Capacity : 4500 m3/dayTechnique : ROWater Salinity input : 3,7 g/lWater salinity output : 0,7 g/l
Kerkenah Iseland
Functioning since 1995Production Capacity : 30000 m3/dayTechnique : ROWater Salinity input : 3,2 g/l
Water salinity output : 0,2 g/l
Gabes City
Functioning since 1999Production Capacity : 15000 m3/dayTechnique : ROWater Salinity input : 6 g/l
Water salinity output : 0,2 g/l
Zarzis City
Functionning since 2000Production Capacity : 20000 m3/dayTechnique : RO
B. Water Salinity input : 5.5 g/l
Water salinity output : 0,2 g/l
Jerba Iseland� The actual Total installed
capacity = 110.000 m3/d,
200.000 m3/d (2010) and
500.000 m3/d (2050)
� 70 desalination units
� Location : South
� 3,7 % of the total water
production in Tunisia (7% in
2020)
Water Desalination in Tunisia
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Uses of desalted water by activity in Tunisia (year 2005)
Potable Water
Tourism
Electricity
Industry
Others
57%24,5%
4,5%
9,1%
4,5%
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Desalination techniques used in Tunisia
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The Cost of the desalted water in US $/m3
Capacity (m3/day) Sea Water Brackish Water
4000 1,3 0,7
8000 0,9 0,4
20000 0,7 0,25
40000 0,65 0,22
60000 0,6 0,2
• The Total volume of desalted water during the year 2005
by SONEDE is 14,4 Mm3
• The total cost of the desalted water is 0,4 US $ /m3
� Invetment cost : 0,23 US $/m3
� Exploitation Cost : 0,17 US $/m3
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•All these desalination plants function by conventional energy
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Energy Situation Energy Situation Energy Situation
In TunisiaIn TunisiaIn Tunisia
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Crude Oil Resources in North Africa
0
2000
4000
6000
8000
Algeria Tunisia Libya
Crude Oil resources in
Million of Tones
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Energy demand projections in Tunisia Energy demand projections in Tunisia (in Mtep)(in Mtep)
Year
1998 2001 2010
Oil products 3,48 3,90 5,60
Natural gas 0,51 0,62 1,30
Electricity 0,60 0,80 1,40
Coke 0,06 0,08 0,10
Solar --- --- 0,10
Total 4,65 5,40 8,50
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Evolution of the Energetic Balance in Tunisia
• Fall of the production of fossil energy.
• Growth of the local request of the petroleum products
Since 2000,Tunisia is in energetic deficit.
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Energy Balance
Tunisia has not important energy resources
Energy consumption 8.5 Mtep per year
Energy available2.9 Mtep per year
Projection in 2010
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The Rural Population In The Rural Population In The Rural Population In TunisiaTunisiaTunisia
Water & EnergyWater & EnergyWater & Energy
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The Rural Population in Tunisia
• 2 Millions of inhabitants ≈ 20% of the population
• Dispersed population
• Average Water needs : 20 - 50 m3/day
• Water is managed by GIC «Grouping with collective interest ».
• Bad quality of distributes water
• Used for domestic tasks
• Cost of this Water is 0,4 US $/m3
• In Kairouan some families have to walk about 10 km to have potable water
• In Kebili the potable water is sold at place
• The cost of the potable water : 20 – 32 US$ / m3
• This water caused diseases (Diarrhoea until the renal calculi).
• Families are ready to pay more to have better quality water.27 / 79
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Characteristics of water demand in Tunisia(National Statistic Study, 2004)
� For small capacity the conventional Desalination techniques are not economic
� Desalination by Renewable Energy could be a potential solution
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Desalination by Renewable Desalination by Renewable Desalination by Renewable Energies in TunisiaEnergies in TunisiaEnergies in Tunisia
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Desalination by Renewable Energies
Tunisia has an abundant and readily available
renewable energy sources :
� Solar,
� Wind
� Geothermal energy30 / 79
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Plausible Coupling combination between renewable energies and desalting technologies
Desalting technologies
Solar
Wind
Geothermal
ME
�
�
MSF
�
�
�
RO
�
�
�
�
Renewable energy sources
Solar thermal
Solar photovoltaic
Wind shaft
Wind electric
Geothermal heat
Geothermal electric
ED
�
�
�
TVC
�
�
MVC
�
�
�
�
�
�
HDD
�
�
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Plausible Coupling combination between renewable energies and desalting technologies
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Desalination proecesses used inconjunction with renewable energies
MSF (10%)
RO (62%)
ED (5%)
Other (4%)
VC (5%) Wind (20%)Hybrid (10%)
Solar PV (43%)
Solar Thermal (27%)
Energy sources for desalination
Desalination by Renewable Energies
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-Theorical Investigation.-M3 cost goes frim 1.6€ (RO + electric gird) to 1.1€ (RO+Wind) and to 0.95€ for (RO+electric gird+wind) for an average wind velocity of 5.1m/s.-For a plabt (Solar+MED) the cost was estimated to 2.7€/m3.
D.Jezli – «APPLICATIONS OF SOLAR AND WIND ENERGY SOURCES TO SEA-WATER DESALINATION- ECONOMICAL ASPECTS ». Morroco 2004.
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- Theorical investigation.- Algeria has a good RE Potential : Solar on all thecountry and wind in coastaland montanious regions of thesouth.
Banque Mondial / BRL ingénierie, “Seawater and Brackish Water Desalination in the Middle East, North Africa and Central Asia”.
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- Operational plant.- Sea water, RO+PV+Wind+fuel(300 m3/j)
Lahmeyer International , Reverse Osmosis Sea Water Desalination by Renewable Energy Sources (SWRO + RES), Ras Ejder, Liby, Allemagne 2004
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- Theorical Investigation.- SWRO, Electric Energy, 100 m3/d, 1.47€ � 1.20€/m3 when improving the system
E.Ezzanati, “Development of a locally designed and manufactured small-scale reverse osmosis desalination system”, NRC, Egypte, 2004.
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- Study of the actual situation. - Good potential for brackish water desalination by RE
Mousa S. Mohsen, «Brackish water desalination: an alternative for water supplyenhancement in Jordan », ASU, Jordan, 1999.
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- Experimental plant, sea water, RO, PV, win, Batteries, 1 m3/d, 23€/m3
E. TZEN : Desalination units powered by renewable energy sources, CRES
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- Operational unit.- Sea Water, RO, PV, Batteries, 50 m3/d, 6 €/m3
E. TZEN : Desalination units powered by renewable energy sources, CRES
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- Operational Unit.- Sea Water, RO, Wind, Batteries, 7 m3/d, 3-5€/m3.
E. TZEN : Desalination units powered by renewable energy sources, CRES
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-Cartography of Tunisia by RE potential(Solar, wind, geothermal).-Good sola potential on all the country.-Wind in coastal regions.-Geothermal in the south .
I. Houcine, «Renewable energysources for water desalting in Tunisia », INRST, 1999
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Renewable Energies in Tunisia
• Tunisia has:• Good solar potential energy on the whole of the countryespecially area of the south (1.600-2.000 KWh/m²year)
• Satisfying Wind potential energy in the coastal and mountainous areas (600-900 KWh/m²an).
• Geothermal potential energy relatively low (low enthalpy)and concentrated in the southern areas.
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The Problem : No Clear Strategy
� What are the regions that present an urgent need to
develop autonomous desalination units ?
� Which desalination technique is the most adequate ?
� Which Renewable Energy to use ?
� Is the coupling possible and economic ?
� What are the criterias to involve ?
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Methodology
Defining the parameters involved to integrate autonomous desalination unit1
Collection of the Data in each region of Tunisia2
Determining the level for each criteria3
Application of the FMEA Method + Pareto4
Zoning of the country in three regions : Zone I : Urgent Development of ADURES, Zone II : Not Urgent Need to ADURES,
Zone III : No Need to ADURES5
Software to optimize the coupling : Desalination - Renewable6 45 / 79
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Some Solar Desalination Some Solar Desalination Some Solar Desalination Projects in TunisiaProjects in TunisiaProjects in Tunisia
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Multiple Effect Distillation Project
(INRST)
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Experimental Set Up : R0-PV (INRST)
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Experimentation of one HDD unit in the Region of Kebili (ENIT)
• The cooling operation of groundwater rejects in the atmosphere
an important quantity of thermal energy (8 107 kcal/h)
• Evaporative cooling
• Inlet water temperature : 65 – 75°C
• A pilot was tested for two years (1996 – 1998)
• Capacity production : 2 m3/day
• Cost of cubic meter = 1,2 Euro/m3
• Optimizing the components of the process
• Determining the optimal operating conditions
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Solarwater
collector
Humidifier
Dehumidifier
Cooling WaterOut
Cooling Waterin
Storage tankWater makes up
Solar air collector
Air Path
1
1
2
2
3
3The HDD Process
Water Path
Tin.w, Min.w
Tin.a, Min.a Humin.a
Saturation
Moisture ContentKgw/kga
T
W
Dry-bulb temperature °C 50 / 79
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Desalination by Air Humidification and Dehumidification
Q
Hot waterHot water(Solar, (Solar, Geothermal)Geothermal)
PreheatedPreheatedSalt waterSalt water
Humid airHumid air
CooledCooledwaterwater
Salt Salt waterwater
Distilled WaterDistilled Water
Evaporator Condenser
UT U X
T
UT U X
T Q
QTT Q
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Optimizing the Coupling of the desalination “HDD”Unit to solar Collectors :
Aux.1
Aux 2
Humidifier
Tin.w = 80°C
Tin.a = 50°C
1st config. : solar water collector only
Aux.1
Aux 2
Humidifier
Tin.w = 80°C
Tin.a = 50°C
2nd config. : solar water + Air collectors
Aux.1
Aux 2
Humidifier
Tin.w = 80°C
Tin.a = 50°C
3rd config. : solar water collector + Storage system
Reservoir
4th config. : solar water + Air collectors + Storage system
Aux.1
Humidifier
Tin.w = 80°C
Tin.a = 50°C
Reservoir
Aux 2
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Performance of the system
• Quantity of evaporated water : mev
• Fraction of the solar energy consumed :
• Cost of evaporated water
Fr = Solar Energy Consumption
Total Energy Consumption
Simulations on Trynsis53 / 79
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Simulation on trynsis
• The inlet tempertures in the humidifier are constants (Air and water) � Auxilliary systems
• Analyse of the behavior of the differentcomponents :– Solar water and air collectors– Auxilliary systems– Storage system– Sluices– Regulation
• Using the weather conditions of Tunis City (One year)
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Questions?
• What is the best configuration?
• What is the maximum amount of evaporated water?
• What are the optimal surface collectors (Water and
Air)
• What is the maximum solar fraction?
• What is the minimum cost of distilled water?
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Life Cycle analysis
IrCOZnCICG −+= **
Z =
++−
−+ n
aj
jaj
n 1'11
''11
Normation factor :
� Actualization,
� Rise,
� Inflation, Relatif Rise, etc.56 / 79
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Integrated Desalination System
• Objective :Developing integrated water
Desalination systems in
Green houses
(Chaibi and Bourouni 1999)
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The ROThe ROThe RO---PV ProjectPV ProjectPV Project
Of the Ksar GhilOf the Ksar GhilOf the Ksar Ghilèèène Villagene Villagene Village
Inauguration, May 2007
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Ksar Ghilène Location
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Characteristics of the village
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Ksar Ghilène : Project Objectives
� Supply of Drinking Water to the population� Installation of a desalination unit supplied by a solar PV system
� Dissemination of the results� Management of the produced water
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Water Supply : Needs and Solution
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Canary Islands of Technology (ITC)
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Phase of the projects
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Project Description
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Source of Water
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System Diagram
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General Description
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Building
� Passive cooling : Semi-buried construction
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PV Solar Generator
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Simulation
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RO Desalination Unit
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� 50 m2 of PV Collectors
� Investment Cost : 300.000 US $
� In June 2008, Experimental results will be presented
Projects data
Similar Project
� Tunisian-Japanaise Cooperation
� Twenty ADURES Systemes 0,5 – 20 m3/day + PV applications
in the south of Tunisia
� Feasability study
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Conclusions & PerspectivesConclusions & PerspectivesConclusions & Perspectives
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Conclusions
� Problems of water and Energy in Rural regions
� Desalination by renewale energies is one of the solution to be considered
� The decision concerning :� To Identify the regions presenting an urgent need?� Wich Desalination technique (RO, HD, ect.)? � Which Renewable energy? Is very complicated (number of parameters)
� This decision must be done on the base of optimization 75 / 79
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• The decision require a large number of competences : – Desalination techniques (Mechanic, heat and mass transfer, membranes, etc.)
– Renewable energies (Solar PV + Thermal, Wind, Geothermal)
– Water management– Economie– Sociology– Environmental
Conclusions
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Future Project (in Preparation to Submit to Nato):
Hybrid RO-PV-Wind
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• Meteo Data onSolar, wind, etc. in the selected Loc.
• Energy Requirement
Future Project : Hybrid RO-PV-Wind
• Water demand• Brackish watercharacteristics
• Dimensionning the RO units
• More interestingConfiguration
•Simulations on•RO + Wind•R0 + PV•R0 + PV + Wind•Hybrid
•Simulations on•RO + Wind•R0 + PV•R0 + PV + Wind•Hybrid
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Thank You for your Attention
« One drop of water is enough to create a world »« One drop of water is enough to create a world »
Gaston BachelardGaston Bachelard
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Ecole Nationale d'Ingénieurs de Tunis. B.P. 37 Le belvédère 1002 TUNIS. Phone: (216) 71 874 700 - Fax: (216) 71 872 729 - Info: www.enit.rnu.tn
Email : [email protected]; [email protected]
