Contents - Previous - Next

This is the old United Nations University website. Visit the new site at

The Aqaba hybrid scheme

Construction of any new thermal or nuclear power station in the region would benefit from a pumped-storage scheme for efficient off-peak energy use. Hybrid water-energy co-generation is the application of sea-water pumped-storage with reverse osmosis desalination 1993; Murakami and Musiake, 1994). The Aqaba scheme (see fig. 11.6) would pump sea water during off-peak periods to store it in an upper reservoir at the top of an escarpment 600 m above sealevel. The stored sea water would be discharged into a penstock shaft to yield an effective water pressure of 60 kg/cm2 at the end of the pressure pipe system, simultaneously generating 600 MW of peak electricity and producing 100 MCM of fresh potable water (see fig. 11.7). Off-peak electricity to lift the sea water to 600 m above sealevel would be supplied not only from a steam power plant at Aqaba but also from steam power plants in either Egypt or Israel, or from other regional electricity grids.

Fig. 11.6 Aqaba regional development plan with hybrid sea-water pumped-storage scheme for co-generation

Conceptual design

The volume of sea water pumped for co-generation is estimated to be 50 m3/s, comprising 39 m3/sec. for peak power electricity generation and 11 m3/sec. of feed water for reverse osmosis desalination. The theoretical hydro potential to exploit the head difference of 600 m with 39 m3/sec. of pumped sea water is estimated to be 200 MW, assuming a specific weight of sea water of 1.03 and a synthesized efficiency of 0.85. The discharge and installed capacity of the hydropower plant are preliminarily estimated to be 116 m3/sec. and 600 MW, respectively, assuming 8 hours a day of marginal peak operation. The annual power output from the 600 MW plant would amount to 1.5 billion kWh with a generating efficiency of 0.85.

Marginal operation of the reverse osmosis system would make use of the hydro-potential energy in a penstock pipeline with 600 m of head difference for 16-24 hours a day. The feed sea-water requirements for producing 100 MCM of permeate per year (with 5001,000 mg/litre of TDS) are estimated to be 333 MCM, assuming a 30 per cent recovery ratio (70 per cent for brine reject water with 53,000 mg/litre of TDS). The installed capacity of the reverse osmosis unit is estimated to be 322,300 m3/d with a load factor of 85 per cent.

The potential energy recovery from the brine reject is estimated to be 29.5 MW, assuming 20 per cent of friction loss in the reverse osmosis circuit. The annual production of electricity from the reverse osmosis brine reject is estimated to be 175 million kWh with a load factor of 68 per cent. The brine would then be discharged into the Dead Sea (Murakami and Musiake, 1994). The recovered energy would be used to supply electricity for the post-treatment process or to other pumps to save electricity on the national grid.

Fig. 11.7 Schematic profile of the Aqaba hybrid sea-water pumped-storage scheme with reverse osmosis desalination

Table 11.2 The major cost elements of the Aqaba hybrid sea-water RO desalination unit (preliminary estimates in 1990 prices)

Major capital cost element (US$)
Pre-treatment 44,195,000
Desalting plant 70,414,000
RO membrane/equipment 84,835,000
Control and operating system 5,952,000
Appurtenant works 27,013,000
Powerline and substation 11,427,000
Energy recovery/turbinea 2,999,000
Sub-total 246,835,000
Design and construction management 62,250,000
Financial expenditure 80,270,000
Total 389,355,000
Major O&M cost element (US$/yr)
Labour 3,718,000
Material supply 1,860,000
Chemicals 7,440,000
Power (pumped-storage for RO feedwater/permeateb) 3,100,000
Membrane replacement 28,269,000
Total 44,387,000

a. Energy recovery unit generates electricity from brine reject water of 233 MCM.
b. Assuming US$0.02/kWh of off-peak electricity tariff for pumping 100 MCM.

Cost estimates and water economy

The cost of a unilateral 600 MW pumped-storage scheme is estimated to be US$1 billion at 1990 prices. The total investment cost of the proposed hydro-powered sea-water reverse osmosis desalination plant is preliminarily estimated to be US$389.4 million assuming: a plant life of 20 years, a membrane life (replacement) of 3 years, 8 per cent interest during the three years of construction, the exclusion of cost benefits from energy recovery, and the exclusion of the costs of source water and pipeline/distribution (Murakami, 1991, 1993). The annual costs are estimated to be US$18.6 million in financing the major capital cost element and US$44.4 million in operation and maintenance (O&M) elements, as shown in table 11.2.

Water economy is examined by comparing the unilateral pumped-storage scheme and the hybrid pumped-storage scheme with reverse osmosis desalination. The annual benefit of the hybrid scheme is 1.4 times greater than the unilateral scheme, assuming tariffs of US$0.1/kWh of peak electricity and US$1.0/m3 of fresh potable water. The cost and benefit elements are shown in table 11.3.

The unit water cost of hydro-powered sea-water reverse osmosis desalination, which assumes a shadow benefit of using 11 m3/sec. of feed water for the sole purpose of hydroelectricity generation, is estimated to be US$0.69/m3 (= 0.63+0.059). The economy of this method can be seen when it is compared with either US$1.6-2.7/m3 for conventional desalination such as reverse osmosis and multi-stage flush (Murakami 1991, 1995) or unilateral hydropower (see table 11.3).

Method of sharing resources and benefits

The Aqaba hybrid sea-water pumped-storage scheme for co-generation would include the following inter-state cooperation scenarios to share the resources and benefits:

1. An inter-state electricity grid or network that would include Egypt, Israel, Palestine, Jordan, and Saudi Arabia is incorporated in the plan to transfer inexpensive night and morning off-peak electricity to the pumped-storage scheme (buying) and to deliver valuable day and evening peak electricity to neighbouring states (selling).

2. An inter-state water pipeline system connecting three states (Egypt, Israel, and Jordan) along the Aqaba coastline is constructed in order to share fresh potable water from the hydro-powered reverse osmosis desalination plant at Aqaba, Jordan.

3. An inter-state sanitation and water environment management programme, which includes treated wastewater recovery for tree crop and garden irrigation as well as for protecting the clean water environment of Aqaba bay, will be incorporated in the plan. The application of membrane separation technology, including microfilter and/or ultra-filter techniques, will also be adopted in the process of tertiary wastewater treatment for re-use for limited irrigation (Murakami and Musiake 1994; Murakami, 1995).

Fresh potable water amounting to 100 MCM per year from the Aqaba hydro-powered reverse osmosis desalination plant in the pumped-storage scheme could be shared among Jordan (Aqaba), Israel (Eilat), Egypt (Taba), and Saudi Arabia (Haq) in accordance with a possible agreement within the inter-state regional economic development programme (see fig. 11.6). The non-oil-producing state of Jordan, whose national economy is not as strong as those of Israel and Saudi Arabia, would have an exclusive chance to export 100 MCM per year of fresh, potable water. It would also be able to export valuable peak electricity as well as to import cheap off-peak electricity from Israel, Egypt, and Saudi Arabia. The Aqaba hydro-powered sea-water desalination plant would also save 17.5 MCM of fossil groundwater currently being pumped from the Disi aquifer to Aqaba for its municipal water supply (Murakami and Musiake, 1991).

Table 11.3 Cost and benefit elements between unilateral and co-generation schemes (assuming tariffs of US$0.1/kWh of peak electricity and US$1.0/m3 of potable fresh water)

Type Feed water Electricity Permeate Output/Salea Project cost Annual cost element (US$m.)
(MMC/sec) (million kWh/yr) (MMC/yr) (US$m./yr) (US$m.) Capital O&M Total Differenceb
Unilateral pumped-storage (for power generation only):
Hydroelectricity 50 1,482   148.2 1,000 50.0 10.0 60.0 88.2
Hybrid pumped-storage with hydro-powered RO desalination:
Hydroelectricity 39 1,156   139.6 905 39.0 10.0 49.0  
RO desalination 11 175 100 100.0a 390 18.6 44.4 63.0  
Total 50 1,331 100 239.6 1,295 57.6 54.4 112.0 127.6

a. Output/Sale does not include the benefit of energy recovery of 175 million kWh in the RO unit.
b Difference = (Annual output/sale - Annual cost in total).

Inter-state cooperation for joint development and use among the riparian parties (including Jordan, Israel, Egypt, and Saudi Arabia) takes into account the following: efficient use and/or saving of energy or oil, with an initiative for global environment perspectives; a long-term flexible supply of peak electricity and fresh water; and fewer political constraints, with geo-political initiatives, incentives, and favours for Jordan. The pumped-storage facility would pump water up to a higher elevation for storage during off-peak hours and would simultaneously produce fresh water and hydroelectricity whenever demand peaked. This facility would be conceived for initial incorporation into the canal project. The hybrid sea-water pumped-storage scheme for co-generation is at the planning stage, but it will be important to spell out the coordination required, including international cooperation, in the next phase of projects that will also need innovative research including membrane separation technologies.

Techno-political assessment of the Peace Drainage Canal and the Med/Red-Dead Sea canal

The water budget of the Dead Sea indicates that a decrease of inflow from the Jordan River catchment would result in the additional introduction of Mediterranean water, thereby increasing the system's hydro-potential energy. Without the Med/Red-Dead Sea Canal project, the Dead Sea will continue to drop in level and shrink in size (see table 11.4). Although not much wildlife is being affected (except for bacteria, the Dead Sea is appropriately named), potash works and health resorts on both shores will continue to contend with the costs of an increasingly distant shoreline. One clear environmental benefit of the project would be the restoration of the Dead Sea to its historical level.

The Declaration of Principles between Israel and the PLO on 13 September 1993 would suggest that the best priority project is to connect the Mediterranean Sea (Gaze) and the Dead Sea by a series of canals and a tunnel conduit with a total length of 100 km. The original idea of the Med-Dead Sea (MDS) Canal scheme was conceived in a feasibility study by Israel in 1980 to elaborate the best alternative of 27 optional routes (WPDC, 1980). The trilateral economic committee (Jordan, Israel, and the World Bank) on the integrated development of the Jordan Valley elaborated some new ideas on the Red-Dead Sea Canal in 1994 (World Bank, 1994). Their canal route has a length of 200 km. The original idea was examined by Jordan in 1981 (JVA, 1981; WPDC, 1983). Either of these two strategic options would be a confidence-building measure in the Dead Sea region to supply peak hydroelectricity with or without a supply of fresh potable water by hydro-powered reverse osmosis desalination (Murakami, 1991, 1995; WPDC, 1989).

Table 11.4 Approximate water budget of the Dead Sea with non-conventional techno-political alternative schemes (MCM/yr)

  Before 1948 After 1967 Plus MDS Plus MDS+PDC
Ground elevation below sealevel (m) -391a -406 -391 -392
Surface area of the Dead Sea (km2) 1,000 900 1,000 1,000
Annual flow potential from the whole catchment 1,600 1,600 1,600 1,600
- Inflow from catchment of the Jordan River 1,100 400 224b 211b
- Inflow from catchment of the Dead Sea 500 400 223b 211b
Abstraction of flow from the whole catchment nil 800 1,153b 1,178b
Evaporation from the Dead Sea surface -1,600 -1,500    
Evaporation after impounding sea water from Mediterranean     -1,900 - 1,900
Tailrace water from MDS hydropower station     1,220 1,220
Brine reject water from RO plant in MDS     233 233
Brine reject water from RO plant in PDC       25
Inflow potential from the whole catchment 1,600 800 447b 422b
Flow balance 0 -700 0 0

a. The historical equilibrium water level of the Dead Sea before 1930-1948 had been -391m. It will take several decades to fill up the Dead Sea to its historical equilibrium level with sea water at 1,600-2,000 MCM.

b. Some residual flows from the catchment that could be developed at future stages.

The reverse osmosis desalination in the Peace Drainage Canal scheme would also substantially reduce discharges into the Dead Sea. This could add 10 MW of hydro potential (60 million kWh per year of electricity) if the Med-Dead Canal or the Red-Dead Canal is incorporated in the integrated development plan.

A techno-political assessment of non-conventional strategic alternatives, comparing the implications of the "Treaty of Peace" before and after 26 October 1994, is shown in table 11.5 (Wolf and Murakami, 1994). The priority projects of the Peace Drainage Canal, the Aqaba hybrid sea-water pumped-storage scheme, and the MDS Canal for co-generation should be integrated into a strategic master plan for the development of the Jordan Rift Valley.


Inter-state regional economic development is considered to be a key element in sustaining the peace process in the region. The Peace Drainage Canal scheme should have the highest priority in the next phase of an international cooperation programme. This environmentally sound, non-conventional water development and management scheme not only takes into account the incentives for ecopolitical decision-making but also introduces the opportunity for inter-state regional economic development by adding fresh potable water of 75 MMC at a cost of US$0.48/m3.

In a broader context, Aqaba regional development using hybrid sea-water pumped storage for co-generation is possibly of even greater importance for economic development in the whole region because it includes initiatives, incentives, and favours for Jordan. Hydro-powered sea-water desalination in the hybrid pumped-storage system would simultaneously conserve fossil groundwater in Disi.

Table 11.5 Techno-political assessment for the Dead Sea and Aqaba schemes before and after the "Treaty of Peace" between Jordan and Israel of 26 October 1994

Techno-political alternatives

Technical feasibility

Environmental feasibility Economic feasibility Political feasibility Overall feasibility
Financial viability Benefit/cost Sub- total
Quantity Quality Reliability Subtotal
Weight (%) 12.5 5.0 7.5 25.0 25.0 12.5 12.5 25.0 25.0 100.0
After the "Treaty of Peace"
Lower Jordan River Peace Drainage Canal with RO desalination 31.0 66.0 62.0 47.3 55.8 61.0 61.0 61.0 69.0 58.3
Aqaba pumped-storage scheme with hydro- powered sea-water RO desalination 32.5 68.8 57.5 47.3 45.0 52.9 53.6 53.3 53.0 49.6
MDS hydro-solar development with hydro- powered sea-water RO desalination 40.0 72.5 60. 52.5 45.0 33.8 48.3 41.1 35.3 43.5
Dead Sea pumped-storage 15.0 30.0 60.0 31.5 40.0 53.3 40.0 46.7 46.7 41.2
Mediterranean-Dead Sea Canal, without RO desalination 23.8 31.3 61.3 36.6 22.5 36.3 30.0 33.2 38.5 32.7
Red-Dead Sea Canal, without RO desalination 21.3 30.0 28.8 25.3 22.5 33.8 30.0 31.9 44.2 31.0
Before the "Treaty of Peace"
Lower Jordan River Peace Drainage Canal with RO desalination 31.0 66.0 62.0 47.3 55.8 61.0 61.0 61.0 69.0 58.3
Aqaba pumped-storage scheme with hydro- powered sea-water RO desalination 32.5 68.8 57.5 47.3 26.3 370 375 37.3 24.0 33.7
MDS hydro-solar development with hydro-powered sea-water RO desalination 40.0 72.5 60.0 52.5 45.0 33.8 33.8 33.8 35.3 41.7
Dead Sea pumped-storage 15.0 30.0 60.0 31.5 40.0 53.3 40.0 46.7 46.7 41.2
Mediterranean-Dead Sea Canal, without RO desalination 23.8 31.3 61.3 36.6 22.5 36.3 30.0 33.2 38.5 32.7
Red-Dead Sea Canal, without RO desalination 21.3 30.0 28.8 25.3 22.5 33.8 30.0 31.9 31.0 27.7

Sources: before the "Treaty of Peace" - Wolf and Murakami (1994, Ref. 13); after the "Treaty of Peace" - some details on cost estimates and environment impact analysis were added by Murakami.

The unit water cost of hydro-powered reverse osmosis desalination is preliminarily estimated to be US$0.69/m3. Such a scheme would be even more competitive when compared with a single-purpose hydropower scheme such as Dead Sea pumped storage or Med/Red-Dead Sea Canal for power generation only. The new idea of a hybrid seawater pumped-storage scheme for co-generation at Aqaba will be carefully examined to compare its feasibility and benefits in relation to the other strategic options, including the Med/Red-Dead Canal.

The proposed co-generation schemes would have a flexible capacity to reallocate outputs and benefits in response to a long-term change in demand for water and peak electricity, thus introducing some incentives for peaceful cooperation and inter-state regional economic development. Once a canal system and reverse osmosis desalination plant were in place, even under different sovereignties, the incentive to connect two or three more states, later, in order to develop consequent ancillary projects could be powerful enough to induce ever-increasing cooperation. The riparians of the Dead Sea and Aqaba bay, including Israel, Palestine (West Bank), and Jordan (East Bank), would see the possibility of achieving comprehensive economic development and a lasting peace to share the region's resources and benefits.


I wish to express my deep appreciation to Prof. Katsumi Musiake of the University of Tokyo and Prof. Yuzo Akatsuka of Saitama University. Special thanks are due to Profs. Asit K. Biswas (chairman of the International Water Resources Association Committee on International Waters), John Kolars (University of Michigan), John Waterby (Princeton University), and Aaron T. Wolf (University of Alabama) for their guidance and invaluable advice. I am also grateful to Prof. Heitor Gurgulino De Souza and Dr. Juha Uitto of the United Nations University, who managed the strategic research project on water for peace and conflict resolution of the international waters in the Middle East, and to the staff of the World Bank, including Mr. Usaid El-Hambali, Mr. John S. Ijichi, Mr. Yo Kimura, Mr. John A. Hayward, Dr. Ulrich Kuffner, and Mr. Alexander MacPhail, for their comments and information.


Glueckstern, P. 1982. "Preliminary consideration of combining a large reverse osmosis plant with the Mediterranean-Dead Sea project." Desalination 40, pp. 143-156.

JVA (Jordan Valley Authority). 1981 "Potential for the development of hydropower between the Red Sea and Dead Sea." Harza Overseas Engineering Co., Ltd., Main Report.

Murakami, M. 1991. "Arid zone water resources planning study with applications of non-conventional alternatives." Ph.D thesis, University of Tokyo, Japan, December.

_____1993. "Hydro-powered reverse osmosis (RO) desalination for co-generation: A Middle East case study." Proceedings of the IDA and WRPC World Congress on Desalination and Water Treatment: Vol. II. Yokohama, Japan, pp. 37-44.

_____1995. Managing Water for Peace in the Middle East: Alternative Strategies. Tokyo: United Nations University Press.

Murakami, M. and K. Musiake. 1991. "Hydro-powered reverse osmosis (RO) desalination for co-generation." Proceedings of IWRA International Seminar on "Efficient Water Use", Mexico City, pp. 688-695.

_____1994. "Non-conventional water resources development alternatives to satisfy the water demand of 21st century." Proceedings of XIII IWRA World Congress on Water Resources, October, Cairo, Egypt. International Water Resources Association, vol. 1, pp. (T5-S1)2.1-19.

Tahal Israel. 1982. Dead Sea Power Station: Interim Report on Present State of Planning. Report prepared for the Mediterranean-Dead Sea Co.

Wolf, A. T. and M. Murakami. 1994. "Techno-political decision making for water resources development: The Jordan River watershed." Proceedings of XIII IWRA World Congress on Water Resources, October, Cairo, Egypt. International Water Resources Association, vol. 2, pp. (T5-S2)7.1-16.

World Bank. 1994. "Integrated Development of the Jordan Rift Valley." Draft, October, pp. 6-19.

WPDC (Water Power and Dam Construction). 1980. "Israel decides on canal route." International News, October, p. 4.

_____1983. "Jordan attacks Dead Sea project." International News, March, p. 4.

_____1989. "Dead Sea P-S scheme revived." World News, May, p. 3.

Contents - Previous - Next