A Quick Overview of the Kidatu Dam and Location

A Quick Overview of the Kidatu Dam and Location

The Kidatu power station was constructed in two distinct parts under the name Great Ruaha Power Project. Phase 1 was carried out in the 1970s, while Phase 2 was done in the 1980s. Phase 1 comprised the building of an earth-rock fill dam, a starting capacity of 2 x 50 megawatts, as well as a 220kv transmission line to the port city of Dar es Salaam through Morogoro. The second phase was completed in 1980, involving the addition of 2 x 50 megawatts and the construction of a larger storage dam at Mtera, with a capacity of 3200 m3.

Two massive rehabilitation works have been carried out at the Kidatu plant. The first phase of rehabilitation covered the repair of the first and second turbines, repair of a spoilt generator unit, and the replacement of excitation tools. The rehabilitation exercise was done between 1993 and 1994. The project cost approximately SEK25 million. TANESCO and SIDA paid for it. Rehabilitation works commenced in 1999 and ended in 2003. The major work done was the computerization of the protection and control system, turbine repairs, replacement of the runners on units 2 and 1, waterways, and generators. TANESCO, SIDA, and NORAD financed it. The estimated cost was approximately US$ 12 million.


Kidatu Tanzania Energy Contribution 

The power plant generates an average of 800 million units annually for the last half of a decade. However, the plant can produce more than one billion units in a good year. Kidatu Power Station contributes approximately 36 percent of the total hydro installed capacity.

Maintenance and Operation

IGSS32 (interactive graphic supervisory system) is a semi-automated computerized system that controls the operation of the generating units. This new control system has three major parts – supervision and data control system, local control unit, and station control unit. The local control unit is used to control each plant (like 33kV/220 substation, dam, and machines), while the station control unit is used to control the entire station. Every local control unit is linked to the supervision and data control system (SCADA) through a station control unit.

The unit control units are linked via Profibus. If the station control unit or SCADA fails, the machines can be started from the local control unit. The Ubungo grid control center is also used for starting or stopping the machines remotely.

The bar chart maintenance system was used in carrying out maintenance initially until a computerized maintenance management system (Job Tech) was introduced. Norconsult Norway supplied the system during the second phase of rehabilitation. The bar chart system was manually done. It was quite slow and lacked reliable record keeping, which is difficult to follow up. The Job Tech system at Kidatu helps with resource utilization and work tasks, builds valuable maintenance history and information, and ensures that all planned work tasks are done. It also secures a cost-effective plant operation and helps ensure optimal maintenance, which prevents unexpected breakdowns. Nevertheless, the computerized system has failed because of technical problems with the computer server. The process of restoring the system is currently in progress.

Future Plans

The second phase of the rehabilitation project couldn’t cover all the necessary equipment and plant repairs. Thus, there will be another phase of rehabilitation (Phase III). The project will cover;

  • Rehabilitation of the 220-kilovolt system due to the fact that the substation is the primary link that connects current stations and the new Kidatu power plant to be constructed later
  • Refurbishment and repair of auxiliary equipment
  • Realignment of the up-bracket of generator number 2
Kidatu Dam  
Height (m) 40
Crest length (m) 350
Dam type Earth rock fill
Fill volume (m3) 800,000
Concrete volume (m3) 40,000
Live storage (mill m3) 125
Catchment area (km2) 10
Spillway capacity (m3/s) 6,000
Kidatu Power Plant  
Total capacity 200
Number of units 4
Tailrace tunnel length (km) 1.0
Headrace tunnel length (km) 9.6
Head (m) 175
Rock excavation volume (mill. m3) 1.0
Discharge capacity via turbines 140

Project Financing and Cost

Phase I cost approximately US$102 million, financed by the Tanzanian Government, the International Bank for Development and Reconstruction, the Canadian International Development Agency as well as the Swedish International Development Authority. Swedish Consulting Group Stockholm supervised the project layout for the Kidatu power station and dam. Other Kidatu plant contractors are:

Substation and transmission line COMSTOCK Limited
Civil works KICON and CG Jensen
Penstock steel lining and gates HITACHI and INGRA-METALNA
Cranes and Turbines JM VOITH and INGRA-LITOSTROJ
Main transformers ASEA and Ferranti-Packard
Cooling water pipes Balfour Kilpatrick International Limited
Air condition ETCO
22kV cables ASEA Cable
Control equipment and control gear BBC and COGELEX

Other Things Nearby Kidatu That are Important – National Sugar Institute Kidatu

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