January 23rd, 2020

Expansion of the Gogo hydropower plant in Kenya

Interior view of the powerhouse

The existing Gogo hydropower plant is located in the Migori district of southwestern Kenya on the Kuja River near Lake Victoria. The Gogo hydroelectric power station, which was put into operation in 1958 and has a drop height of about 20 m and a current expansion run-off of 11 m3/s, has an installed capacity of 2 MW.

The power plant consists of a heavy-duty dam, an underground drive water and pressure pipe with an intermediate water lock and a power house with two identical Kaplan turbines. The water for the power plant operation is taken from the Kuja River, which is dammed up by the dam.

During the power plant operation, which has now lasted six decades, the reservoir has almost completely landed, which leads to an impairment of the plant's energy production, especially in dry seasons. In addition, the entire machine and electrical system technology, such as turbines, generators and locking elements, is very outdated and damaged.

For these reasons, only about 1 MW of power plant capacity can currently be generated. In addition, the 33 kV power line, which connects the powerhouse to the Awendo substation, is about 20 km long, with regular outages, some of which are repeated several times a day. The state-owned energy supplier and operator Kenya Electricity Generating Company (KenGen) intends to renew and expand the power plant site in order to meet the increasing energy demand in the agricultural region of southwest Kenya.

To this end, KenGen, in cooperation with the Delegation of the European Union to Kenya (EU), initiated the project of a pre-feasibility study for the upgrading of Gogo    Hydropower Plant. In April 2019, the CONSORTIUM SAFEGE – Tractebel Hydroprojekt GmbH was commissioned to carry out this pre-feasibility study. The aim of the study was to determine the optimum degree of expansion at the Gogo power plant site for a replacement new building.

For this purpose, investigations on hydrology, geology and geotechnics were carried out as a basis for the planning. A local subcontractor carried out additional on-site surveys for the consortium. Subsequently, numerous technical variants were developed for the renewal and expansion of the plant. For example, various dam and powerhouse locations, different types of dams and dam heights as well as different expansion drains and turbine types were examined in detail.

The technical planning showed that an increase in the expansion capacity to up to 20 MW is possible at the Gogo power plant site. With the involvement of local engineers, partial studies were also carried out on the energy market and the electricity grid in Kenya, as well as on the nature conservation and social impact of the project (PESIA- Study). During the planning phase, numerous site visits were also carried out by Specialist Engineers from Tractebel. The study has been in its final phase since December 2019. The final presentation of the study to customers KenGen and EU in Nairobi is scheduled for mid-January 2020.

Matthias Feldmann – München

Dam from the air side