Technology options for Renewable desalination on islands

1. Technology options for Renewable desalination on islands Martinique 23.06.2015 Verena Jülch Noha Saad Hussein Joachim Koschikowski Fraunhofer Institute for Solar Energy Systems ISE Jeffrey skeer IRENA www.ise.fraunhofer.de 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 Wind Geothermal Oceanic Solar 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. 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,… Electrically driven desalination process RO (Reverse Osmosis) ED (Electro Dialysis) ... Thermal Desalination process MED (Multi Effect Distillation) MSF (Multi Stage Flash)…….

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 Coolingblow down Cooling Number of effects 1 -20 Electricalenergyinput Energy demand Investment costs 1.5-2.5kWh/m³product Seawater at 20 – 35°C Heat at 70°C 60 kWh/m³

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

10. 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

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. Thank you for your kind attention !

20. Cost comparison for 250m³/day plants Input parameter for desalination systems

21. Cost comparison for 250m³/day plants Input parameter for calculation of energy costs