Sizing up African hydro4 October 2011
A wide range of project sizes are under development in Africa from the mid-range Ruzizi project to large schemes like the Mandaya-Beko Abo and Millennium projects. Report by Patrick Reynolds
Hydropower developments underway in Africa, like many parts of Asia, have a dramatic range in size. Among the mid-level developments underway is the Ruzizi III project, which is the next step in a cascade development being undertaken by a three-country partnership – the Democratic Republic of Congo (DRC), Rwanda and Burundi. The project is to be developed on a public-private partnership basis and recently had four potential developers shortlisted.
DRC is vastly hydro rich, and will see further developments on the Inga schemes. But for the continent as a whole another key area of development is Ethiopia, where among the many schemes being progressed, aside from those on the Gibe River.
A series of large projects are to be built on the Blue Nile, including the Millennium and the Mandaya-Beko Abo schemes. Together they represent more than 9,000MW of installed capacity. Construction got underway in April for the Millennium project while studies will continue into next year for the Mandaya and Beko Abo projects.
Four international consortia have been shortlisted as potential developer/investors for the 145MW Ruzizi III project, the third plan to be built in the four-station cascade on the Ruzizi River in the border area between DRC and Rwanda. The project is being sponsored by the two countries in collaboration with neighbouring Burundi, as together they act through Energie des Grands Lacs (EGL), or Great Lakes Energy, which is owned by the Economic Community of the Great Lakes Countries (CEPGL).
The consortia are: US joint venture IPS/Sithe Global; SN Power Africa, of Norway; India’s GMR Infra; and, the Argentinian-Zambian JV Impsa/Copperbelt. The four consortia were selected by EGL’s evaluation committee which met in late May, and the shortlist was announced in mid-June. EGL had extended the deadline for proposals to early May from the original request for submissions by late February.
Last month, Round Table talks were held by EGL in collaboration with the European Investment Bank (EIB). At the meeting, the technical and institutional studies for the project were presented. European money had financed early studies for the medium-head, run-of-river Ruzizi III project, and which were carried out by German consultant Fichtner. EGL has been supported in the development of the scheme by French consultant Sofreco.
“The Ruzizi hydropower project has received crucial European support since its re-launch in 2007,” says director of EGL, Prof Pierre Muzyumba Mwanahembe.
Ruzizi III will be built downstream of Lake Kivu but before the Ruzizi River meets Lake Tanganyika. It will feature an embankment dam and separate powerhouse. Upstream of the site is located the first two plants in the cascade – Ruzizi I (29.8MW) and Ruzizi II (43.8MW). The last plant in the series, Ruzizi IV is to be constructed upstream of the site, closer to the existing stations.
The cascade has hydropower potential of approximately 500MW, says EGL. The committed plants (I-III) have combined capacities of almost 219MW, and Ruzizi IV is expected to be 287MW though the pre-feasibility studies looked at a size of just over 200MW.
The Ruzizi III project, with an estimated cost at least Euro 378 million (US$543 million – though earlier this year the Request for Proposals [RfP] noted a budget of approximately US$450 million), is to be funded on a 70:30 debt-to-equity basis. The successful investor/developer from the shortlist is to organise half the debt funding as well as provide the equity. The balance of debt is to be provided by bilateral and multilateral organisations.
To be operational by around 2016, the Ruzizi III plant is to house three Francis turbines and the station will have a load factor of 54% - like Ruzizi IV, when it is eventually built. The Ruzizi stations have been developed at long intervals, beginning in late 1950s then the second plant was commissioned thirty years later in 1989, and it is almost the same period again before Ruzizi III is due to become operational. The project will also see refurbishment work undertaken at Ruzizi I & II.
At the end of last year, the three governments agreed that a river basin authority will be established to ensure equitable use of the water resources in the area.
Ethiopia – Millennium & Mandaya, Beko Abo
Early site work is getting underway for the 5,250MW Millennium scheme, in Ethiopia, following the award of the construction contract earlier this year to Italian contractor Salini. The project is being developed by the Ethiopian Electric Power Corp (Eepco), in the state of Benishangul-Gumaz, and the first generating units are due to be commissioned in September 2014.
To be constructed on the Blue Nile, approximately 750km north west of the capital Addis Ababa, the project involves construction of a 145m high, 1780m long RCC dam , powerhouses on opposite banks of the river at the toe of the dam, and a 5km long saddle dam. The dam will have a gated spillway with five radial gates to discharge a probable maximum flood (PMF) of 11,870m3/sec. The saddle dam will have an emergency side spillway.
The project is expected to generate more than 15,100 GWh of electricity per year. The 3500MW right bank powerhouse will hold 10 x 350MW Francis turbines and the 1750MW left bank station five of the same units.
Salini said it is using its “Fast Track Implementation” method, which pushes concurrent development of project phases and can halve construction time.
Also, in Ethiopia and on the Blue Nile, studies are underway – supported by Norway – for the development of the 2000MW Mandaya and 2100MW Beko Abo projects. The latest studies are due for completion by the middle of next year.
Extensive reservoir impounding is foreseen for the projects which are expected to again feature large RCC dam construction, at sites 300km apart. While they are separate projects the headwaters of the lower, Mandaya scheme will extend all the way up to the location of Beko Abo.
The Mandaya and Beko Abo dams are provisionally sized at heights of 200m and 285m, respectively. Behind the Beko Abo dam the reservoir is to be about 150km long. The power stations at the dams are to generate 12,100GWh and 12,600GWh of electricity annually, respectively.
Studies are being undertaken by Norplan/Multiconsult with Norconsult, Scott Wilson and Electricite de France (edf). The companies were involved in the early studies for the schemes, the Norwegians working with German firm lahmeyer to focus on Beko Abo while the UK firm and EdF looked at Mandaya. Design studies on Mandaya are the more advanced of the two schemes.