Transmission grids key to regional energy development
New electricity transmission lines are needed in southern Africa to enable all countries to share and benefit from increased generation capacity across borders.
Full integration of transmission would allow member states of the Southern African Power Pool (SAPP) to sell surplus electricity to one another through a competitive market.
The SAPP coordination centre manager, Dr Lawrence Musaba, has said that substantial financial resources are needed to strengthen the transmission grid, adding that member states and a number of potential investors have shown keen interest in the projects.
“Over US$5.6 billion will be required to develop the identified transmission projects,” he told a recent Africa Clean Energy Corridor meeting held in Abu Dhabi.
Musaba said that priority transmission projects have been identified for commissioning over the next few years to ensure that all countries in the region are connected.
Priority projects include the Zimbabwe-Zambia-Botswana-Namibia (ZiZaBoNa) transmission project, the Malawi-Mozambique interconnector, and the Central Transmission Corridor (CTC).
The Southern African Development Community (SADC) is not yet fully integrated in terms of energy needs for the expanding regional economy as Angola, Malawi and the United Republic of Tanzania are not yet connected to the regional power pool.
This means that any new generation capacity installed in any of the three countries is not accessible to the nine other members of SAPP, the regional body that coordinates the planning, generation, transmission and marketing of electricity on behalf of Member State utilities in SADC.
The other members are Botswana, the Democratic Republic of Congo, Lesotho, Mozambique, Namibia, Swaziland, South Africa, Zambia and Zimbabwe.
Interconnection also creates new corridors that can support industrial development and improve energy security in other parts of the region without being stifled by overloads on the existing transmission lines.
The ZiZaBoNa transmission project, which links four countries, has the capacity to increase power trading among the participating utilities, as well as provide an alternative route and help to decongest the existing central transmission corridor that passes through Zimbabwe.
Under the ZiZaBoNa agreement, all four countries’ respective power utilities are expected to finance parts of the project that fall within their national boundaries.
Total funding requirement for the project is estimated at more than US$223 million, comprising US$67 million equity and US$156 million debt financing.
The project is to be implemented in two phases, with the first covering construction of a 120kilometre line from Hwange Power Station to Victoria Falls where a switching station will be built on the Zimbabwe side. The line will extend to a substation at Livingstone in Zambia.
The second phase involves construction of a 300 km line from Livingstone to Katima Mulilo in Namibia, through Pandamatenga in Botswana.
When fully operational, the ZiZaBoNa line will make it possible for Namibia to import power directly from Hwange in Zimbabwe. Currently electricity from the Hwange Power Station is being routed to Namibia through South Africa.
The other major interconnection planned for SADC is the Malawi-Mozambique interconnector that links the two countries, allowing Malawi to have access to the regional market through Mozambique’s interconnected grid with Zimbabwe (Songo-Bindura) and South Africa (Songo-Apollo).
This will also enable other SADC countries to access power from Malawi, as it will be connected to the regional grid.
The project entails the construction of a 220 kilovolt transmission line joining Matambo Substation in Mozambique to the proposed Phombeya substation in Malawi. A 220km overhead transmission line and optical fibre ground wire from Matambo sub-station in Mozambique to Phombeya sub-station in Malawi will be built. Total cost is estimated at more than US$82 million.
With respect to the CTC in Zimbabwe, the project involves construction of power lines to increase the north-south transfer capacity of the Zimbabwean network from 200kV to 600kV.
This corridor is critical for SADC, as most utilities in the region use the Zimbabwe network for their power wheeling.
The project entails the development of transmission lines from Alaska to Sherwood, Bindura to Mutorashanga, and Marvel to Insukamini in Zimbabwe.
A static VAR compressor will be built at Dema and Sherwood substations. The cost for the project is about US$100 million.
The Mozambique Regional Transmission Backbone project (STE) will consists of a double transmission line from the Tete Province in Centre Mozambique to the capital Maputo in southern Mozambique and SAPP interconnected power network.
It will transport the electricity generated in new hydropower plants from Mphanda Nkuwa (1500 MW) and Cahora Bassa (North Bank, 1245 MW) to the markets.
The backbone will comprise a 400kV HVAC line and an 800 kV line to supply the major consumption zones within Mozambique and link with the South African market. Its estimated cost is US$2.8 billion. ‑ sardc.net