French independent power producer (IPP) EDF Renewables, a subsidiary of state-owned utility Électricité de France (EDF) Group, has commissioned South Africa’s first self-build main transmission substation (MTS).

The Koruson 400/132-kV substation, located outside Noupoort in the Northern Cape, will connect 1.5 GW of renewable energy to the national grid, as reported by Engineering News on April 7.

The MTS has been developed by a consortium led by EDF Renewables, in collaboration with South African black economic empowerment (BEE) partners H1 Holdings, Gibb-Crede, and a local community trust. The partners are also developing the adjacent Koruson 1 renewable energy project cluster, which comprises three wind farms - Phezukomoya, San Kraal and Coleskop - each with installed capacities of 140 MW, totalling 420 MW. The Koruson 1 project is part of Round 5 of the IPP Office’s Renewable Energy Independent Power Producer Procurement Programme (REIPPPP).

“This is the first greenfield transmission substation in more than seven years to be connected to the grid, and it is the first greenfield transmission substation that is a full self-build, meaning it was developed, financed, engineered, built and commissioned by an IPP,” Tshepo Tshivhasa, head of grid engineering at EDF Renewables, is quoted as saying. “It is also the first time that the National Transmission Company of South Africa (NTCSA) has approved a self-build scope of works of this magnitude.”

The MTS is integrated into an existing 400-kV overhead transmission line, providing connections for nearby renewable energy projects ready to start exporting energy. The development’s Phase 1 will connect the three wind farms from the Koruson 1 cluster of projects to the grid.

“This main transmission substation has also seen the implementation of a full suite of latest Phase 6 protection, control and automation schemes, enhancing operational reliability and efficiency, some of which was specifically developed as part of this project,” EDF Renewables senior project manager Carl Wlotzka said, as quoted by Engineering News.

“Additionally, the integration of the substation into the existing transmission network alters grid dynamics, requiring modifications, such as the replacement of two 400-kV towers with new 400-kV transposition towers, to ensure compliance with the latest operational standards,” he added.

In Phase 2, Anglo American’s jointly owned renewable energy venture with EDF Renewables, Envusa Energy, will add one solar and two wind projects to the grid. These three renewable energy projects, known as the Koruson 2 cluster of projects and located on the border of the Northern and Eastern Cape provinces of South Africa, will have a total capacity of 520 MW of wind and solar electricity generation.

Each renewable energy facility will be connected to the grid through its own distribution link with the state-owned power utility Eskom’s infrastructure, which includes 132-kV overhead power lines and switching stations. These will be constructed under a self-build agreement with the national grid operator.

“This ‘first of its kind’ project lays the foundations for future self-build, and NTCSA, projects in South Africa,” said EDF Renewables CEO Tristan de Drouas. “This project marks a significant step in strengthening South Africa’s renewable-energy infrastructure while maintaining grid stability and efficiency.”