1. Technology options for Renewable desalination on islands
Martinique
Verena Jülch
Noha Saad Hussein
Joachim Koschikowski
Fraunhofer Institute for Solar Energy Systems ISE
Jeffrey skeer
IRENA 1

2. Development of the desalination market
Desalination for industrial and domestic fresh water supply is of increasing importance!
Global Capacity :
88 Mio m³/day
Membrane based technologies have increasing share

3. Development of the desalination market
Desalination in “Small Development Islands States”
17 Selected SDIS* Capacity :
700,000 m³/day
RO - technology dominates the market with 80%
*SDIS include: Antigua and Barbuda, Bahamas, Barbados, Cuba, Dominican Republic, Saint Lucia, Saint Vincent and the Grenadines, Trinidad and Tobago, Cape Verde, Comoros, Maldives, Mauritius, Seychelles, Fiji, Kiribati, Marshall Islands, Papua-New Guinea

4. Scope of the Study: “Technology options for Renewable desalination on islands”
Review of renewable desalination technologies which:
Are Scalable for island size (small to medium 10 – 1000m³/day)
Are close to market entry
Have the technological and economical potential to contribute significantly to water supply on islands

5. Overview on desalination technologies
Renewable energy sources for desalination
Solar
Wind
Geothermal
Oceanic
RO: Reverse Osmosis
ED: Electro Dialysis
MSF: Multi stage flash
MED: Multi Effect Distillation
VC: Vapor Compression
STIL: Simple Solar Stil
MEH: Multi Effect Distillation
MD: Membrane Distillation

6. Thermal Desalination process Electrically driven desalination process
Overview on desalination technologies
Renewable energy sources for desalination
Renewable energy source
Heat
(Solar thermal, geothermal,…)
Heat and electricity
(CSP power plant, Biomass, …)
Electricity
PV, Wind- , Ocean- power,…
Thermal Desalination process
MED (Multi Effect Distillation)
MSF (Multi Stage Flash) …….
Electrically driven desalination process
RO (Reverse Osmosis)
ED (Electro Dialysis) ...

7. Different technological approaches
Solar still, simplest technology for solar desalination
Heat losses: about 600kWh/m³
Disadvantage: Very inefficient (2 – 4 l/m² day)

8. Desalination technologies
Basic set up of a Multi Effect Desalination (MED) system
Cooling blow down
Cooling
Sea water at 20 – 35°C
Heat at 70°C
60 kWh/m³
Number of effects 1 -20
Electrical energy input
kWh/m³product
Energy demand
Investment costs

9. Desalination technologies
Examples of Multi Effect Desalination system
10m³/day unit by Fischer Ecosolutions
36Tm³/day plant in Trapani (Sicily)

10. Co-gene- ration power plant
Desalination technologies
Heat supply for Multi Effect Distillation system
Solar thermal flat plate or vacuum tubular collectors
CSP with or without power production
Waste heat from cogeneration plants
Geothermal heat
Co-gene- ration power plant

11. Desalination technologies
Basic set up of a Reverse Osmosis (RO) system
60 – 80bar
Electrical power
3.5-6 kWh/tproduct
Pressure recovery

12. Desalination technologies
Examples for Reverse Osmosis (RO) system
60 – 80bar
Pressure recovery

13. Desalination technologies
Energy supply Reverse Osmosis (RO) system
PV-RO - stand alone system configuration with and without back up for small and medium scale application

14. Cost comparison for 250m³/day plants
Investigated Combinations of RE-Desalination
MED RO
CSP
continuous operation with storage, power production not considered, cost for heat are related to system costs
Continuous operation, heat considered as free of charge
Continuous operation with electrical power production and storage PV
24h operation on grid back up
24h operation off grid battery storage
7h operation off grid small battery
Wind
Off grid discontinuous operation
24h operation 12 to 24% coverage by wind 88 to 76% by Grid

15. Cost comparison for 250m³/day plants
Cost comparison of different RE desalination systems (WACC = 5% + 10%)
MED is the cheapest option if:
Heat is for free
Electrical energy costs are 0.20 to 0.50US$
MED is expensive if:
Heat is supplied by fossil fuel
Solar thermal collectors

16. Cost comparison for 250m³/day plants
Cost comparison of different RE desalination systems (WACC = 5% + 10%)
The lowest water production costs (2.30 – 3.30 US$/m³) for PV-RO off grid can be achieved in systems without battery storage (7h/day operation)
A battery doubles the costs
A grid back up can reduce the costs depending on electricity costs

17. Cost comparison for 250m³/day plants
Cost comparison of different RE desalination systems (WACC = 5% + 10%)
Water production costs for off – grid wind – RO are between 2.00 and 7.70€/m³ depending on full load hours.
Grid back up can reduce the costs to 2.00 to 4.00€/m³

18. Conclusion
Renewable desalination is affordable and can be the cheapest and sometimes even the only option particular in remote areas
The best technological solution for a particular site must be investigated with respect to the local boundary conditions
In many cases renewable driven desalination needs significant investment but it relies on “quasi unlimited”, clean and free of charge sources: Sun and Sea (high CAPEX – low OPEX)
Renewable desalination technologies exist but still need adaptation to local boundary conditions, transient operation is essential
Well guided and monitored pilot implementation is essential to make renewable desalination a success

19. DME - Seminar Desalination and Renewable Energies
January 19th - 20th, Jülich, Germany
Thank you for your kind attention !
DME - Deutsche MeerwasserEntsalzung e.V.

20. Cost comparison for 250m³/day plants
Input parameter for desalination systems
Unit
RO discontinuous operation
RO continuous operation
MED continuous operation
Total plant capacity in 24h
[m³/day]
250
Nominal capacity
[m³/h] 36 11
Operation time / day
[h/day] 7 24
Spec electrical energy consumption
[kWh/m³]
4.3
1.55
Specific heat consumption - 53
Capex
[$/m³/day ]
1930
2320
1700
Opex (except electricity)
[$/m³]
0.32
WACC
[%]
5; 10

21. Cost comparison for 250m³/day plants
Input parameter for calculation of energy costs PV
7h, 24h
CSP electricity
CSP heat
Wind
Grid
Battery storage
Diesel generator
Capacity
[kWp]
[kWh]*
230, 243
100,000 50,000
143,000
45, 100 -
1280*
25… 10,000
Global /Direct* irradiance
[kWh/m² year]
2000
2000*...
2500*
2000* *
Full load hours
[h/a]
2000…
8000
Capex
[$/kWp]
[$/kWh]*
1470
9960
4450
3890
2660
1.50*
260…
1170
Opex
[$/kWp/a] 40
0.038
0.019
329
147
0.26…0.39
WACC
[%]
5;10
LCOE
LCOH*
[$/kWh]
0.11…
..0.15
0.32…
..0.59
0.08…
0.11*
0.18…
…0.46
0.20…
…0.50
0.23…
…0.48