HYDROELECTRICITY

EMPOWERING THE PEOPLE

Cohorra Bassa power project

CAHORA BASSA HYDROELECTRIC COMPLEX

The Cahora Bassa Hydroelectric Complex has been in operation since 1975 and comprises a variety of engineering infrastructures – the Hydroelectric Power Station, the Songo Converter Substation, the HVDC and HVAC Transmission Lines and the Matambo Substation - enabling the production, transmission and commercialisation of energy. These elements are expertly integrated in line with global operational standards, allowing for the production of clean energy with high fidelity and quality.

See the HCB Structure

CAHORA BASSA DAM

The dam is located in a narrow river gorge with vertical slopes at the top and a v-shape at the bottom

Key stats

KEY STATS:

Area: 2900 km2

Max length: 270 km

Maximum width: 30 km

Capacity: 52 km2

Foundation thickness: 21.5 m

Maximum discharge capacity: 14.000 m3/s

Hydroelectric Power Station

HYDROELECTRIC POWER STATION

The hydroelectric power station is situated on the south bank of the river: 220 m long, 29 m wide and 57 m high. It comprises five generator sets, each formed by a Francis turbine of 415 MW.

The generator sets are rotated at nominal speed of 107.11 rpm, which corresponds to the 50 Hz electric frequency used across the Mozambican power grid.

Songo Converter Substation

SONGO CONVERTER SUBSTATION

This substation converts alternating current (from the central power station) into direct current, which is injected into the HVDC transmission lines. The eight-way conversion bridges are formed by oil-cooled thyristor tanks fed through appropriate transformers.

HVDC Transmission Lines

HVDC TRANSMISSION LINES

The Songo and Apollo substations (located in Mozambique and South Africa respectively) are linked by two monopoly transport lines, covering a distance of 1.400 km. Approximately 900 km of this is situated in Mozambican territory along the border with Zimbabwe.

6.400 towers, about 49 m high, suspend relevant conductors.

HVAC

HVAC TRANSMISSION LINES AND MATAMBO SUBSTATION

Two power transmission lines have been installed to connect both the Songo substations to the Matambo substations, near the city of Tete. This then supplies power to the central and northern regions of Mozambique. The Matambo substation includes, among others, a transmission line that feeds into the Chibata substation, near Chimoio City.

ENGINEERING PROJECTS

With a firm focus on continuous improvement and the provision and transport of reliable, quality power, HCB prioritises the ongoing development of the Cahora Bassa Hydroelectric Power Plant. This includes enhancing performance levels (whilst being cognisant of environmental factors) as well as implementing additional engineering projects, with the aim of achieving strategic business objectives.

CURRENT PROJECTS

CAPEX VITAL

This investment plan focuses on the rehabilitation of specific transport and production elements, including critical sections of the Songo and Matambo substations as well as equipment upgrades for the southern production plant.

REABSUB - HCB will endeavour to replace equipment older than 40 years at the Songo substation, focusing on all cutting and manoeuvring equipment, auxiliary services equipment, converter valves and control and protection systems (including the Greed Master Power Control).

REABMAT - In addition, improvements
will be made to the transportation and supply systems in the central and northern regions of the country at Matambo substation.

REABSUL - 2 - The south central
rehabilitation project, which also forms part of Capex Vital, will prioritise the enhancement of output capabilities through the addition of power elevating transformers and auxiliary services equipment.

STE: NATIONAL ENERGY TRANSMISSION SYSTEM PROJECT

This technical project includes the construction of two lines, one for direct current (HVDC) and one for alternating current (HVAC) to serve the internal power requirements of the region; facilitating further integration and connection within the country’s national energy network. STE will allow for the efficient and cost-effective transmission of 9,000 MW of power from the Zambezi Valley with substations planned inCataxa, Matambo, Inchope, Vilanculos, Chibuto, and Moamba.

MPANDA NKUWA HYDROELECTRIC PROJECT

This project is proposed for the central region of Mozambique, in the Province of Tete. The dam will be located about 60km downstream from the Cahora Bassa Dam and 70km upstream from the City of Tete, ending near the districts of Chiúta (on the northern bank) and Changara (on the southern bank). The reservoir that will be created by the dam will also extend to the districts of Cahora Bassa and Marávia. This initiative will increase capacity by 1500 MW, benefiting both domestic and cross-border markets; addressing the medium and long-term demand for energy.