Feasibility of Small scale Solar Powered RO Desalination. Dr. Mohamed A. Dawoud Manager, Water Resources Department Environment Agency Abu Dhabi

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1 Feasibility of Small scale Solar Powered RO Desalination Dr. Mohamed A. Dawoud Manager, Water Resources Department Environment Agency Abu Dhabi

2 Historical Background

3 Water Resources in Abu Dhabi Emirate Groundwater Desalination Treated Wastewater

4 Water Demand in Abu Dhabi Emirate Domestic Forests Agriculture Parks and Amenity Industerial and Commercial

5 101 MGD 39 MGD 145 MGD 297 MGD 102 MGD Desalination Plants Capacity and Production in Abu Dhabi Desalination Plants and Daily Production Capacity Sharjah Qidfa Dubai ADPS Taweelah Umm Al Mirfa Nar Shuweihat Total Desalination Capacity Number of Desalination Plants Abu Dhabi Emirate Desalination Plant 683 MGD or 3.1 Mm 3 / day (current) 969 MGD or 4.4 Mm 3 / day (by 2012) 6 currently available 3 planned for 2010, 2011 and 2012 Daily Desalinated Water Capacity and Production Capacity Utilisation (%) Capacity Production 1) Production figures exclude exports Source: ADWEC Statistical Reports and ; Abu Dhabi Water Resources Masterplan; Env2030 Team analysis Excess Capacit 378 y CAGR ( ) Annual 1990 Production 1992(in Mm ) II. Desalinated Water % % 80% 84% 88% 66% 86% 81% 64% 69% 76% 79%

6 6 ADWEC Desalinated Water Demand and Capacity Forecasts In MGD (2010F-2030F) 710 Demand - Required Capacity Current and Planned Capacity Surplus/ Deficit Capacity Addition of Fujairah F2 (134 MGD) Addition of Shuweihat S2 (151 MGD) Addition of Shuweihat S3 (101 MGD) , , , , II. Desalinated Water ~ 400 MGD Capacity Required by , Annual Surplus 0 (+) or Deficit 1 (-) (in Mm 3 ) Surplus (+) or Deficit (-) as % of Required Capacity +15.1% +15.3% +13.7% -1.3% -4.4% -7.7% -17.3% -24.2% -28.6% Comments Projections of desalination future demand and capacity are based on ADWEC forecasts of domestic water demand and planned capacity additions Water capacity is expected to increase between 2010 and 2012 with the operationalisation of new plants at Fujairah F2 as well as Shuweihat S2 and S3 ADWEC forecasts do not take into account future plans to install capacity beyond 2012 Shortage of fuel would severely constrain new desalination capacity installations in the future and operations of current desalination plants

7 Increasing Efficiency Assessment of Desalination Technologies Abu Dhabi Desalination Capacity by Technology - In MGD - ( ) % 13% % 9% 5% 2008 MSF MED RO Multistage Flash Distillatio n (MSF) Multieffect Distillatio n (MED) Reverse Osmosis (RO) Description Produce fresh water by evaporating heated seawater in a vacuum evaporator and condensing the vapour Heat efficiency is improved by recovering the latent heat of the condensed vapour and flash-boiling the water at each stage Utilise steam or waste heat from power production/chemical processes to evaporate seawater in one or more stages at low temperatures (less than 70 C) to produce clean distilled water Involve low electricity consumption and high production per thermal unit Pass seawater at high pressure through semipermeable membranes to produce fresh water Dissolved impurities remain behind and are discharged in a waste stream Energy-efficient process that does not use steam, unlike distillation Total Cost (US$/m 3 ) Energy Consumptio n (kwh/m 3 ) Saline Feed Water per m 3 of Fresh Water Discharged 1 ) Water per m 3 of Fresh Water II. Desalinated Water Applicability to Abu Dhabi Enable cogeneration of water and electricity with efficiencies of scale in desalination Allow generation of large volumes Exposed to fuel price fluctuations May not be suitable to Abu Dhabi due to limited production capacity of MED plants Exposed to fuel price fluctuations Difficult to implement in Abu Dhabi due to abundance of algae, high salinity and elevated sea water temperatures Constrained by production Country Examples KSA Bahrai n Bahrain Oman USA Qatar USA Australia Singapore UK

8 Environmental Impacts ADWEA Plants Fuel Consumption attributed to Water Production - In Billion BTU - ( ) 140,089 +6% 164, ,294 8, CO 2 Emissions from Water Desalination - In Thousand Metric Tons - ( ) 6, NOx Emissions from Water Desalination - In Metric Tons - ( ) Climate Change 8,030 Decrease due to technological upgrades 4,934 3, Air Pollution ,213 SO 2 Emissions from Water Desalination - In Metric Tons - ( ) 1, II. Desalinated Water Environmental Impacts of Increased Fuel Consumption Water desalination in Abu Dhabi is an energy-intensive activity with non-renewable fossil fuel consumption reaching 167,294 Billion BTU in 2008, as a result of increasing production Due to high energy consumption, the desalination industry is exacerbating air pollution through NOx and SO 2 emissions; however, the following should be noted: NOx emissions are decreasing due to technological upgrades SO2 emissions fluctuate depending if oil is used instead of natural gas In addition, the water production sector is the second largest emitter of CO 2 and contributor to climate change after the oil sector in Abu Dhabi Fuel consumption is expected to continue to increase as new desalination capacity becomes operational

9 Groundwater Deterioration

10 Solar Desalination Project

11 Design Technical Details Small Community No connection to power or water grid High demand for water Capacity Feed Water Source Feed Water Salinity (ppm) 60 m 3 /day Product Recovery (% ) 65-70% Brackish Groundwater Less than 35,000 ppm Pressure (kpa) 1.1 x x 10 3 Power Requirement (kw) Product Salinity ( ppm ) Brine water ppm Evaporation bond

12 Design Technical Details = AC/DC Inverters ~ PV Panels Feed Pump Pretreatment System HP Pump Flushing Pump RO membrane Freshwater Tank Energy Recovery System Groundwater Well Brine water Evaporation Pond

13 Site Photos

14 Design Technical Details

15 Design Technical Details

16 Design Technical Details

17 Main Challenges Sand movement and dust wind (using Doon to protect the site) Discharge of brine water (evaporation bond or irrigation of salt tolerant species) Electrical storage (water storage) Membrane operation during day hours only PVC cleaning (automated self cleaning system) PVC system

18 Cost analysis input data Plant capacity 40 m3/d RO plant configuration 1stage Feed concentration 35,000 ppm Fouling correction factor 0.7 Atmospheric pressure 100,000 Pa Feed temperature 25 C Salt molecular weight 58.5 kg/kg mol Friction parameter (permeate) Solution viscosity 1.10E m 2 kg/m s Solution density 1100 kg/m3 Diffusivity Mass transport characteristics of membranes Stage 1 1.6E-09 Water permeability coefficient 3.31E 12 m S 1 Pa 1 Salt permeability coefficient 3.34E 07 m/s Mass transfer coefficient 3.76E 05 m/s m2/s

19 Cost analysis PV technology improvement ( ). Parmer PV modules efficiency (%) PV modules cost ($/W p ) System life (years) >20 >25 >25

20 Future Prospective PV technology improvement ( ). Parmer PV modules efficiency (%) PV modules cost ($/W p ) System life (years) >20 >25 >25

21 Shams 1 Shams 1 will be the largest Concentrated Solar Power (CSP) plant in the Middle East. It will extend over an area of 2.5 km², with a capacity of 100 MW and a solar field consisting of 768 parabolic trough collectors to generate clean, renewable electricity. Shams 1 will directly contribute towards Abu Dhabi s target of achieving 7% renewable energy power generation capacity by the year The plant will also contribute toward the diversification of the United Arab Emirates (UAE) energy production mix and help reduce the UAE s carbon footprint. Shams 1 is registered as a project under the United Nations Clean Development Mechanism (CDM) and is eligible for carbon credits. It is the first CSP plant registered under the CDM.

22 Conclusions Integrating desalination units with renewable energy sources is important for addressing the issues related to adverse impacts of climate change. For remote areas, where scarcity of power and water co-exist, the one and only solution to produce safe drinking water is to go in for renewable energy sources. With improvement in PV efficiencies and the subsidies available, cost of PV systems is expected to come down, making the solar PV based desalination systems more costeffective. Advanced membrane pretreatment by ultrafiltration or nanofiltration can potentially reduce fouling and scaling of the RO membranes and thus decrease energy consumption and overall costs. To date, the full potential of dual-purpose designs for the co-generation of power and water has not been sufficiently explored. Such designs have a potential to operate at low water generating costs and levelized electricity costs. An operation strategy with the potential to increase both energy efficiency and permeate water production comprises preheating the RO feed by cooling the PV panels or absorbing rejected thermal energy in solar thermal power systems The development of Concentrating Solar Power (CSP) technologies, on the other hand, will be crucial in determining whether solar desalination will become attractive for large-scale desalination systems.