Slim Zekri & Salem Al-Jabri Economics of Using Desalination Plants in Agriculture Seminar on Small Desalination Units for Agriculture Sustainability: Challenges and Opportunities 5-6 March 2018 Al Nahda resort & Spa, Barka Sultanate of Oman
Desalination • Only 2% of Desalinated water globally is used for agricultural purposes
Main purpose of installation of desalination units Farm Size in Feddans Main Purpose of Desalination < 5 5 to 10 > 10 Total Agriculture 14% 2% 6% 22% Domestic 14% 0% 6% 20% Domestic + Agriculture 38% 14% 6% 58% Total 66% 16% 18% 100%
Main Crops Palm Lemon Mango Grass 0 1 2 3 4 5
Is desalinated water used for intensive agriculture?? Main Purpose of % of farms having Total # of GH Total area in m 2 Desalination GH Agriculture 4% 16 4200 Domestic + Agric 16% 25 4650 Grand Total 20% 41 8850 Classic products lettuce tomato Cucumber 0 0.5 1 1.5 2 2.5 3
Cost of Desalination Average Annual expenses $/m 3 per farm estimated at OR 2,400 Average cropped area = 1.7 Feddan 1.40 Assuming 7,800 m 3 /Feddan Assuming drip irrig. Eff @ 80% 1.20 Cost per Feddan =OR 1,400 1.00 0.80 1.32 0.60 0.40 0.55 0.20 0.46 0.00 Max Avg Min
Cost distribution Cost of Energy 16% O&M costs 8% Capital Cost 77%
Cost Comparison $/m 3 Average volume desalinated 0.70 per year is 13,000 m 3 Max = 41,500 m 3 0.60 Min = 2,000 m 3 0.50 0.65 0.40 0.55 0.30 0.20 0.13 0.10 0.03 0.00 Average cost Average cost with From wells Aflaj water price without electricity electricity subsidy subsidy
International benchmarking • In Spain irrigation water is mixed with 30%-40% of desalinated water. Cost after mixing $0.39/m3 • 78% of farmers in Oman use pure desalinated water for irrigation $/m3 0.70 0.65 0.63 0.60 0.50 0.40 0.40 0.29 0.30 0.20 0.10 0.00 Oman Texas Texas Spain brackish GW Brackish GW Brackish GW Brackish lowest highest groundwater
Why Farmers can afford desalinated water in Spain • Highly skilled full time small farmers • Desalinated water is mixed with surface/GW • Crop water requirement around 5,600 m 3 /ha • High value crops: horticulture, Ornamental plants, Fruit trees • Strong cooperatives controlling part of the marketing chain and getting a fair price for their products • Large European market more than 400 million • Added value 5.79 € /m 3 - 1.08 € /m 3 on average
Who are the Farmers using Desalination in Oman? • Small hobby unskilled farmers • Pure desalinated water is used by 78% at high cost • Crop water requirement around 20,000 m 3 /ha • Low value crops: dates, mango, Lemon • Fragmented non-organized farmers • Narrow market and difficult access to international market due to pesticide residues and absence of cooperatives • Cheap groundwater available for competing farmers
Conclusions • Is desalination a priority? • What if TWW is re-used for irrigation rather than thrown to the sea? • What if Centrally excess desalinated water is used in Winter for agriculture?
Acknowledgement • Thanks for the AFDF for funding this project
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