Hydropower plant (HPP)
Start of Construction
Uganda Electricity Generation Company (UEGCL)
China International Water and Electric Corporation (CWE)
The 188MW Isimba hydropower project (HPP) is one of the most important HPPs that the Ugandan Government has initiated on the White Nile, to ease the severe power shortages in Uganda and accelerate development of the local economy.
Considered to be the fourth biggest HPP in Uganda, the Isimba HPP is expected to generate hydroelectric power at 68 cents per kWh, the lowest in East Africa.
The ground breaking ceremony for the project was conducted on 5 October 2013 with construction expected to be completed in 40 months. The project is anticipated to come online in 2017.
It is expected to generate 1,039GWh of electricity a year and increase the country’s total electric capacity by 23%. The project construction is expected to create approximately 1,000 jobs.
Isimba hydropower project details
The 180MW hydroelectric facility in the Lower Kihansi Gorge, south central Tanzania, has been on stream since December 1999.
The Isimba HPP will be located on the Victoria Nile, downstream of the 205MW Bujagali Falls hydropower plant.
The project will extend over approximately 2,867.6 acres of land and will comprise a concrete gravity dam, a clay-core rockfill dam, a spillway, a power house, electro-mechanical equipment, switching stations and auxiliary power transmission works.
The concrete dam, to be located on the left side, will consist of a reservoir retaining structure in front of the erection bay, while the rockfill type with central clay core right dam will provide storage for emergency gates and stop logs.
The powerhouse structure will feature four 45.8MW Kaplan turbines in the left dam. The Isimba HPP external switchyard will be situated on the left bank of the river. It will be connected with the powerhouse by four overhead lines.
Substation details and transmission of power generated from Isimba HPP
The new Isimba substation will be a double busbar type with two line bays, four transformer bays, one bus coupler and two future bays.
The generated power will be transmitted to the substation at Bujagali HPP through a 132kV Isimba-Bujagali double circuit transmission line. The 42km-long transmission line will have a 30m wayleave, with a 5m right of way.
Isimba hydropower project construction
In addition to the construction of the dam and the double circuit transmission line, the project also includes the construction of a 33kV power line from Kayunga town to the project site, along Busana Road.
Other works will include the construction of a road across the river Nile, to connect Kayunga and Kamuli districts.
Financing for the Isimba power project
The Ugandan project, which is estimated to cost $570m, received debt financing from the China Export-Import Bank (Exim). In March 2015, the Parliament of Uganda also approved a $482.5m loan from the Exim Bank.
Contractors involved with the Ugandan power project
On behalf of the Government of Uganda, the Uganda Electricity Generation Company (UETCL) was appointed as the Project Implementing Agency for the Isimba HPP.
China International Water and Electric Corporation (CWE) was awarded the $568m engineering, procurement and construction (EPC) contract for the project. The contract, signed between CWE and the Ministry of Energy and Mineral Development of Uganda on 6 September 2013, includes the construction of the power plant and the Isimba-Bujagali 132kV interconnection line.
CWE engaged Geotech Solutions for conducting site supplementary geological investigation, drilling and rock grouting work.
Energy Infratech was engaged as the supervision consultant for the project. The joint venture of Fichtner and Norplan awarded a contract worth $3.8m, in 2010, to carry out a feasibility study and prepare tender documents for the Isimba HPP and the transmission line to Bujagali.
Kagga and Partners, a local Ugandan company, was engaged as a sub-consultant to the joint venture.