Power utility Eskom plans to add about 6 500 km of high-voltage transmission lines and 46 000 MVA of transformer capacity in the next ten years, its latest Transmission Development Plan (TDP), for the period from 2019 to 2028, shows.
The TDP, which was released on Thursday, also demonstrates Eskom’s inclusion of independent power producer (IPP) projects in its transmission network and sets out plans to increase cross-border transmission lines to Namibia, Botswana, Zimbabwe, Mozambique, Swaziland and Lesotho.
The investment in additional transmission infrastructure, along with planned increases in conventional energy generation of about 12 GW, together with 13 GW of renewable energy, to come online by 2028, will ensure access to electricity for more South Africans.
The TDP has undergone adjustments that include the rephasing of capital investment in transmission projects to align with the project execution timelines associated with servitude acquisitions and current available funding.
The TDP was released during a public forum event, which forms part of a consultative process where industry, various business sectors, local government and other infrastructure development partners are able to influence the long-term development plan for the transmission system.
Eskom grid planning GM Mbulelo Kibido said the public forums have become increasingly critical to ensure transparency and collaboration between Eskom and IPPs.
Eskom transmission acting group executive Willy Majola, meanwhile, said significant progress had been made since the last TDP public forum in 2017, including the establishment of transmission network to enable successful connection of additional power generation from the Medupi and Kusile power stations to the national grid, which requires the commissioning of 717 km of transmission lines and 2 500 MVA of transformer capacity.
Over the last decade, South Africa added 11 GW of additional power generation capacity, 8 000 km of transmission lines and 37 000 MVA of substation capacity to its electricity system.
Eskom now generates 52 GW of power, comprising about 90% conventional power generation (of which 73% is coal-fired), 7% renewables and around 2% imports.
By 2028, Eskom expects total generation of 74 GW, comprising about 74% conventional generation (of which 56% is coal-fired), about 23% renewable energy generation and 2% imports.
Connected IPP projects now total 64, producing 3 924 MW nationally.
Majola said the successful integration of additional IPP projects in the last year was underpinned by investment in new substations and transformer capacity enhancements, mainly in the Northern Cape.
The majority of the TDP work for 2019 to 2028 is focused on including IPPs in Eskom’s national grid network.
The Northern Cape has emerged as the priority province in this regard. The province has hydropower generation capacity of about 600 MW, wind generation capacity of about 590 MW, solar photovoltaic (PV) generation capacity of 667 MW and concentrated solar power generation capacity of about 300 MW, amounting to a total 1 567 MW.
The province has a load peak demand of 1 077 MW, which is predicted to increase by 50% to 1 593 MW by 2028, when the province is expected to produce 5 GW of power, which will mostly be exported.
Key development plans for the province includes transmission line strengthening between the Gromis, Nama and Aggeneys substations, while transformer capacity will be expanded at the Helios substation.
Additional transmission lines will be added between the Upington and Aries substations, to expand the corridor that collects IPP generation.
Further, North West province generates 7 MW of power, from a solar PV plant in Rustenburg. Demand in the province is about 3 263 MW, which is imported from other provinces.
A transformer commissioning is planned for Rustenburg, with various substation transmission integrations planned to cater for increased solar PV generation capacity. Load demand is expected to grow to 4 651 MW by 2028.
There are four IPP-related substation expansions planned, concentrated in the Carletonville area. Substation construction is planned for Mafikeng, with a station to be called Mahikeng, which will eventually be linked with a transmission line that is still to be built to the Mookodi substation, near Vryburg.
Limpopo hosts Eskom’s Matimba and Medupi power stations, but four solar PV plants will be commissioned soon. The province’s power generation totals 6 500 MW, half of which is exported to other countries and provinces, since the load demand is at around 3 600 MW.
Main TDP plans for the province include three units to be commissioned at Medupi in the next three years, 400 kV lines to be built to run down from Medupi into North West, and a 400 kV line to be built to run across the province from Medupi to Senakangwedi.
Meanwhile, Mpumalanga has the most extensive transmission network of all nine provinces, owing to it being the hub of power generation in the country – producing around 4 GW.
Load demand for the province is expected to increase by 24% to 2028. Key developments planned for the province include transmission line construction between the Kusile power station and Gauteng, as well as integration into the transmission network of the Khanyisa IPP project.
Gauteng accounts for 30% of all power consumption in the country, with peak grid demand of around 11 GW. There is a 32% load demand growth forecast for the province up to 2028.
Key developments planned for the province include the upgrade of various substations, as well as the construction of four substations near Mesong, Sebenza, Sisimuka and Lesokwana.
In the east of Gauteng, there will be a Jupiter B substation integration project, which entails connection through a 400 kV line from Matla power station, in Mpumalanga. There are also additional grid connection points planned for Pretoria.
KwaZulu-Natal has a peak load demand of about 6 200 MW; however, there is 3 010 MW of power generation capacity, with the gap in demand met by electricity imported from other provinces.
Projected load demand for the province is expected to grow by 20% to about 7 500 MW by 2028. Key developments in the province will include the strengthening of a 765 kV line from the Majuba power station, a 400 kV line between Ariadne and Venus substations, a line between Ariadne and Eros, and a line between Eros and St Faiths substations. St Faiths substation is due for construction soon.
There is also line strengthening planned between the Normandie and Iphiva substations, and subsequently between Iphiva and Duma. Iphiva and Duma will be built soon, in addition to construction of another substation called Nzalo, which is situated between the Umfolozi and Normandie substations.
Free State currently generates 3 761 MW of electricity. Load demand is expected to reach 2 024 MW by 2028.
Key projects in the province include line strengthening between substations in Bloemfontein. Construction is also planned for a new substation called Igesi, which is in the Sasolburg area. The Merapi substation will be commissioned soon.
The Eastern Cape has a peak load demand of 1 716 MW and produces about 1 900 MW of electricity, of which 1 300 MW comprises renewables.
The load demand is expected to grow to 2 387 MW by 2028, the main drivers of which are the industrial development zones in the province. The province will generate 6 692 MW by 2028, comprising gas generation and wind energy generation, resulting in the province becoming a net exporter of power.
Line strengthening is planned between the Neptune and Pembroke substations through a 400 kV line, and between the Poseidon and Pembroke substations. Eskom further plans to build a 760 kV line between the Gamma and Cambridge substations.
The Western Cape has a peak load demand of 3 930 MW, while generating 4 608 MW of electricity, comprising nuclear, gas, pumped storage and wind generation.
A transmission line will be built between the Philippi substation and to-be-built Erica substation.
Load demand is expected to reach 4 527 MW by 2028, owing mostly to growth in the Saldanha Bay industrial development zone. To meet the load growth, Eskom will build extra transmission lines between the Ankerlig and Sterrekus substations.
A new substation is near completion, called Pinotage. The Asteria, Komsberg, Narina and Aghulhas substations will also be commissioned in due course, mostly to cater for IPPs.
A new substation called Bokkom will also be built in the Western Cape.