African Unification Front
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HYDROELECTRIC ENERGY
SHARING ENERGY IN THE AFRICAN UNION
The African Union has 40% of the total world hydroelectric potential. However, the current electric energy needs are not being met in some of the larger industrial districs. In recent years power shortages have become more common in Lagos, and Nairobi, two of the largest industrial centres in Africa. Howerever, power distribution and better management of hydro-electric dams of Akosombo (Ghana) and Owen (Uganda) could resolve the shortage.
Akosombo Hydroelectric Dam
The simple solution to the hydro-electric energy shortages is in sharing between communities. Although this process is well underway, it needs more consistent and systematic structures of administrative and financial support. The most notable achievement in this regard is the establishment of the Southern African Power Pool (SAPP) in 1993 which was signed by all SADC countries in 1995.
The SAPP aims at providing electricity to all SADC countries in an environmentally sound manner and also focuses at drawing hydropower from the Inga Hydropower plant which has a potential of generating up to 100,000MW using the natural flow of the Congo River to turn turbines.
In 1996 all the member states of SADC ratified the Protocol on Energy. The protocol contains the platform for SADC cooperation in energy that was set through the 1982 and 1992 policy documents entitled "towards and Energy Policy for Southern Africa".
Electricity has been shared between the DRC and Zambia as early as the mid-1950s. The Kariba power plant is jointly operated by Zambia and Zimbabwe through the Zambezi River Authority (ZRA) established in 1987, succeeding the Central Africa Power Corporation. The erection of a 340-km long, 220 kilovolts (kV) transmission line between Bulawayo (Zimbabwe) and Francistown (Botswana) is facilitating the export of electricity, mainly hydropower from Zambia to Botswana.
Kariba Dam on the Zambezi
The ZRA has a contract with ESKOM (South African Power company) for the production and sale of hydropower energy. A similar deal has been concluded with Mozambique, including a tripartite agreement between Mozambique, Portugal and South Africa for the rehabilitation of Cahora Bassa infrastructure. Zimbabwe imports about 400MW of power monthly from Cahora Bassa through the Songo-Bindura-Dema 420kV inter-connector while negotiations for 30 percent stake in the Cahora Bassa Hydropower station were ongoing in May 1998.
Meanwhile, a new hydroelectric power station would be built on the Zambezi 70km downstream from Cahora Bassa, ready to come on line as Eskom runs out of excess capacity in the year 2004.
The Zambezi River Basin is well known for its diversity in energy resources: renewable, non-renewable and new energy technologies. Renewable energy sources include biomass, hydropower and ethanol. Non-renewable includes thermal power, coal, petroleum and natural gas. New energy technologies are solar and wind. Renewable energy can be used repeatedly, given appropriate management and conservation. Non-renewable energy has a fixed supply, which will eventually be exhausted.
HYDROELECTRIC ENERGY IN THE NILE BASIN
Zifta, Asyut, Isna, Naj'Hammadi Diversion Dams, Aswan First Dam
In 1843 work begun on diversion dams (barrages or weirs) across the Nile at the head of the delta about 12 miles downstream from Cairo, so as to raise the level of water upstream to supply the irrigation canals and to regulate navigation. The work was not completed until 1861, after which it was extended and improved it was the beginning of modern irrigation dam building in the Nile valley. The Zifta dam, on the Damietta branch of the Nile, was added in 1901. In 1902 the Asyut , 200 miles upstream from Cairo, in 1909 the Isna 160 miles above Asyut, and in 1930 the Naj' Hammadi, 150 miles above Asyut were completed.
Construction on the first Aswan Dam begun 3 years after Emperor Menelik's Defeat of the Italians at Adwa and ended in 1902; it has a series of four locks to allow navigation. The dam has twice been enlarged--first between 1908 and 1911 and again between 1929 and 1934, raising the water level and increasing the dam's capacity. It is also equipped with a hydro-electric plant with an installed power of more than 345 megawatts.
Lake Nasser behind the Aswan High dam
Aswan High Dam
The Aswan High Dam is located about 600 miles upstream from Cairo and 4 miles upstream from the first Aswan Dam. It is built at a place where the river is 1,800 feet wide and has steep banks of granite. The dam is designed to control the Nile water for the expansion of cultivation and for the generation of hydroelectric power and to provide protection downstream for both crops and population against unusually high floods.
The work began in 1959 and was completed in 1970. The High Dam is 12,562 feet long at crest level and 3,280 feet wide at the base, with a height of 364 feet above the riverbed. It has a hydroelectric plant with an installed capacity of 2,100 megawatts. Lake Nasser stretches some 310 miles upstream from the dam site, extending 125 miles into The Sudan.
The principal objective behind the construction of the High Dam is to store sufficient water in the reservoir in order to protect Egypt from the dangers of a series of years of drought. An agreement concluded in 1959 between the two states sets a maximum amount that can be drawn per year and apportions it in a ratio of three to one, with Egypt receiving the larger share. The quantities of water maintained and apportioned are based on the estimated worst possible sequence of flood and drought events over a period of 100 years; and generally, a quarter of the total capacity of Lake Nasser is reserved as relief storage, for the highest anticipated flood during such a period, called century storage.
The Aswan High Dam is also used to create hydro-electricity for Egypt. In the 1980's this dam was providing half of Egypt's Electricity, but by the end of the 1990's this had fallen as energy demands increased. The electric power capacity of the Aswan High Dam is: 2.1 gigawatts (GW). It consists of 12 Hydro-Generators each rated at 175 MW. Egypt currently has a total installed generating capacity of 16.6 gigawatts (GW) compared to 3.8 GW in 1976, thus the percentage contribution by the High dam has decreased from over half the total electricity generation to less than 13%. This percentage will continue to decrease as more thermal power plants are added. Total capacity expected to be 26 GW by 2010.
AFRICA'S WORST ENERGY CONTROVERSY
The High Dam was a source of considerable controversy during its construction, and since it began operation it has continued to have its critics. Opponents have charged that silt-free water flowing below the dam has caused erosion of the downstream barrages and bridge foundations; that the loss of silt downstream has caused coastal erosion in the delta; that the overall reduction in the flow of the Nile resulting from the construction of the dam has caused the inundation of the lower reaches of the river by saltwater from the Mediterranean Sea, with resulting deposition of salt in the delta soils; and that the creation of Lake Nasser has caused the water table along the river to rise, resulting in waterlogging and an increase in soil salinity in some areas.
Already the fish population offshore of the delta has been reduced dramatically by the loss of the nutrient-laden silt. Proponents of the dam have maintained that these harmful effects are worth the security of dependable water and power supplies; and, indeed, Egypt would have suffered a severe water shortage in 1984-88 without the dam.
The historic loss of the ruins of the ancient African capital of due to the flooding caused by the dam is the worst tragedy however. The loss of Nubian and Kushite artifects under lake nasser could have been averted simply expanding dams upriver in Uganda, or Ethiopia, or by building other power sources for Egypt, and establishing an integrated agricultural regime to solve the concerns of the communities in Egypt.
Sannar, Jabal Al Awliya, Khashm Al Qirbah, Ar Rusarys Dams
In The Sudan the Sannar Dam on the Blue Nile provides water for the Al-Jazirah plain at the time of year when the water level of the Blue Nile is low. It also produces hydroelectric power. Another dam, at Jabal al-Awliya' on the White Nile, was completed in 1937; it was built to increase the water available to Egypt during the period of low water (January to June) and was not intended to provide irrigation water for the Sudan. Other dams--including one on the Atbara at Khashm al-Qirbah (completed in 1964) and the Ar-Rusayris Dam on the Blue Nile (1966)--have enabled The Sudan to take maximum advantage of its allocation of waters from Lake Nasser.
Owens falls Dam
In Uganda, Lake Victoria was made into a reservoir by the completion in 1954 of the Owen Falls Dam; the dam is situated on the Victoria Nile just below the point where the lake waters flow into the river. This permits the storage of surplus water in high-flood years to meet the deficit in years when the waters are low. The fall from the lake is harnessed by a hydroelectric plant that provides power for industries in Uganda and Kenya.
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