The Merowe Dam, also known as Merowe High Dam, Merowe Multi-Purpose Hydro Project or Hamdab Dam, is a large dam near Merowe Town in northern Sudan, about 350 km (220 mi) north of the capital Khartoum. its dimensions make it the largest contemporary hydropower project in Africa. It is situated on the river Nile, close to the 4th Cataract where the river divides into multiple smaller branches with large islands in between. Merowe is a city about 40 km (25 mi) downstream from the construction site at Hamdab. The main purpose for building the dam was the generation of electricity
The dam is designed to have a length of about 9 km (5.6 mi) and a crest height of up to 67 m (220 ft). It will consist of polystyrene-faced rockfill dams on each river bank, an earth-rock dam with a pepper core in the left river channel and a live water section in the right river channel (sluices, spillway and power intake dam with turbine housings). Once finished, it will contain a reservoir of 12.5 km3 (3.0 cu mi), or about 20% of the Nile’s annual flow. The reservoir lake is planned to extend 174 km (108 mi) upstream.
The powerhouse will be equipped with ten 125 MW Francis turbines, each one designed for a nominal discharge rate of 300 m/s (980 ft/s), and each one driving a 150 MVA, 15 kV synchronous generator. The planners expect an annual electricity yield of 5.5 TWh, corresponding to an average load of 625 MW, or 50% of the rated load. To utilize the extra generation capacity, the Sudanese power grid will be upgraded and extended as part of the project. It is planned to build about 500 km (310 mi) of new 500 kV aerial transmission line across the Bayudah desert to Atbara, continuing to Omdurman/Khartoum, as well as about 1,000 km (620 mi) of 220 kV lines eastwards to Port Sudan and westwards along the Nile, connecting to Merowe, Dabba and Dongola. planning and construction
The idea of a Nile dam at the 4th cataract is quite old. The authorities of the Anglo-Egyptian Sudan proposed it several times during the first half of the 20th century. It was supposed to equalize the large annual Nile flow fluctuations, create the possibility of growing cotton and provide flood protection for the lower Nile valley. After Sudan achieved independence in 1956, Egypt decided to control the flow of Nile water that reached its own territory by building a dam and creating a reservoir —the Aswan Dam and Nasser Lake.Astronaut photograph of Merowe Dam.
The military government under President Nimeiri revived the plan in 1979, now with the intention of producing hydroelectricity for Sudan’s rising demand. The following decade saw international industry and planning offices busy, producing a total of four feasibility studies [1 - Coyne et Bellier, 1979 / Gibb, Merz & McLellan, GB, 1983 / Sweco, SE, 1984 / Monenco Consultants Ltd., CA, 1989]. However, insufficient funding and lack of investor interest effectively stalled the project at the planning stage.
This appears to have changed fundamentally since the country started exporting oil in commercial quantities in the years 1999/2000. A greatly improved creditworthiness brought an influx of foreign investment, and the contracts for the construction of what is now known as the Merowe Dam project were signed in 2002 and 2003.
The main contractors are:
- China International Water&Electric Corp., China National Water Resources and Hydropower Engineering Corp. (construction of dam, hydromechanical works)
- Lahmeyer International (Germany – planning, project management, civil engineering)
- Alstom (France – generators, turbines)
- Harbin Power Engineering Company, Jilin Province Transmission and Substation Project Company (both China – transmission system extension)
River diversion and work on the concrete dams began in early 2004. The project timeline schedules the reservoir impounding to start in mid-2006 and the first generating unit to go on-line in mid-2007. The work will be finished when the water level in the reservoir will have reached 300 m (980 ft) above MSL and all ten generating units will be operational, scheduled for 2009. The dam was inaugurated on March 3, 2009. Financing
The total project cost is reported to be €1.2 billion. this can be subdivided into partial amounts for the construction work on the dam itself (ca. 45%), its technical equipment (ca. 25%) and the necessary upgrade of the power transmission system (ca. 30%). The project receives funding from
- China Import Export Bank – approx. EUR 240 million
- Arab Fund for Economic and Social Development – approx. EUR 130 million
- Saudi Fund for Development – approx. EUR 130 million
- Oman Fund for Development – approx. EUR 130 million
- Abu Dhabi Fund for Development – approx. EUR 85 million
- Kuwait Fund for Arab Economic Development – approx. EUR 85 million
The remaining cost – approx. EUR 400 million – is supposed to be covered by the Sudanese government.Benefits
The electrification level in Sudan is very low, even by the standards of the region. In 2002, the average Sudanese consumed 58 kWh of electricity per year , i.e., about one fifteenth of their Egyptian neighbors to the north, and less than one hundredth of the OECD average. The capital Khartoum and a few large plantations account for more than two thirds of the country’s electric power demand, while most of the rural areas are not connected to the national grid. many villages use the option of connecting small generators to the ubiquitous diesel-powered irrigation pumps. this way of generating electricity is rather inefficient and expensive.
The combined grid-connected generating capacity in Sudan was 728 MW in 2002, about 45% hydroelectricity and 55% oil-fired thermal plants. However, the effective capacity has always been a lot lower. The two main facilities, the Sennar (constructed in 1925) and Roseires (1966) dams on the Blue Nile, were originally designed for irrigation purposes rather than power production. Generating units were added during the 1960s and 1970s when the demand for electric power increased, but their power production is often heavily restricted by irrigation needs.
The government in Khartoum has announced plans to raise the country’s electrification level from an estimated 30% to about 90% in the mid-term . Large investments into the medium and low voltage distribution grids will be necessary but not sufficient to reach this ambitious goal: First and foremost, the foreseeable increase in power consumption would require the addition of generating capacity. During the 1990s, Sudanese electricity customers have already been plagued by frequent blackouts and brownouts due to insufficient generation. Three new thermal power plants went into operation in the Khartoum area in 2004, increasing the installed capacity to 1315 MW. The Merowe dam with its peak output of 1250 MW will almost double this capacity once it comes online.