South Africa has the most extensive electricity system in sub-Saharan Africa, but much of it was designed for an earlier energy economy. Large coal-fired stations in Mpumalanga and Limpopo supplied mines, heavy industry, cities and municipalities through long transmission corridors. Ageing plants, delayed maintenance, weak municipal networks and limited transmission expansion eventually placed the system under severe strain.
Generation performance improved substantially during 2024 and 2025, reducing the load-shedding that had shaped economic activity. The deeper infrastructure problem, however, has not disappeared. South Africa must maintain an old coal fleet, complete newer units, expand transmission into renewable-rich provinces, strengthen local distribution networks and create an electricity market that can connect many more private generators.
A Coal-Centred Network Must Serve a Different Generation Map
The national grid developed around the location of coal. Most of Eskom’s major coal stations were built near the Mpumalanga Highveld coalfields, with Medupi and Matimba farther north near Lephalale. High-voltage lines then carried bulk electricity toward Gauteng, coastal cities, mines and industrial centres. Koeberg Nuclear Power Station near Cape Town, hydro and pumped-storage facilities, open-cycle gas turbines and regional imports added diversity, but coal remained the central organising force.
New generation is appearing in different places. The strongest utility-scale solar resources are found in the Northern Cape, while major wind development has taken place in the Western and Eastern Cape. These areas are far from the original coal-based backbone and often have limited spare connection capacity. A renewable project can obtain land, permits and finance but still remain unable to proceed if no substation capacity or transmission corridor is available.
This mismatch has turned the grid into one of the main limits on new electricity investment. The system must move power from western and southern renewable regions toward inland demand while continuing to support existing coal stations and major industrial customers.
Generation Recovery Has Reduced Pressure on the System
South Africa’s infrastructure crisis was most visible through load-shedding, but the immediate cause was often poor availability across the generation fleet. Breakdowns at ageing coal plants left the system without enough operating reserve, forcing Eskom to interrupt demand in stages.
The Generation Recovery Plan improved plant performance. For the financial year ending March 2025, Eskom reported an energy availability factor of 60.6%, compared with 54.6% in the previous year. Kusile Unit 5 added about 799 MW, Unit 6 was synchronised, and maintenance and outage management became more stable. By early 2026, the country had experienced a long period with very limited load-shedding.
This recovery creates time for structural investment, but it does not remove the age of the fleet or the need for replacement capacity. Coal stations still require major maintenance, environmental upgrades and reliable coal and water supply. Several plants will eventually close, although retirement schedules may change when security of supply is at risk.
Pumped-storage schemes, hydroelectric stations and open-cycle gas turbines provide flexible output during peak demand or sudden generation losses. These assets will become more valuable as the grid absorbs larger volumes of variable wind and solar power.
Transmission Expansion Is the Critical Construction Programme
The National Transmission Company South Africa has set out a major expansion programme for 2025 to 2034. It includes approximately 14,500 kilometres of new transmission lines, about 210 transformers and extensive substation construction. The expanded network is intended to enable roughly 56 GW of additional generation connections.
Delivery has started, but the required scale is far greater than recent construction rates. Eskom reported adding 292.6 kilometres of transmission lines and 2,620 MVA of transformer capacity during the 2025 financial year. The transmission plan identified 31 projects already under construction that would provide about 1,445 kilometres of lines and 16,945 MVA of transformer capacity.
Cape grid corridors must be strengthened to release wind and solar projects. Gauteng requires additional substations, transformers and lines to support the country’s largest concentration of electricity demand. Northern and eastern corridors must also accommodate new generation, mining activity and cross-border trade.
Transmission construction requires environmental approval, land access, servitudes, engineering capacity, specialised equipment and long-term finance. Transformers and high-voltage components can have lengthy procurement periods, while community negotiations and security problems can delay projects after approval.
NTCSA Changes Who Operates and Opens the Grid
The National Transmission Company South Africa began trading as a separate Eskom subsidiary on 1 July 2024. It is responsible for transmission assets, system operation, grid planning and electricity market functions. This separation supports the move away from a system in which Eskom was simultaneously the dominant generator, network owner and electricity buyer.
The Electricity Regulation Amendment Act, which came into operation in 2025, provides the legal basis for a more competitive electricity market and an independent transmission system operator. Private producers and electricity traders require transparent grid-access rules, published network capacity and tariffs that do not favour one generator.
A more open market will increase the importance of transmission planning. Private wind, solar, storage and gas projects may add capacity more quickly than a single public utility, but only when the network can connect them. The grid is therefore becoming a shared national platform rather than infrastructure designed mainly around Eskom’s power stations.
South Africa’s connections with the Southern African Power Pool allow regional imports, exports and electricity trading. These exchanges can improve resilience when supply conditions differ between neighbouring countries, although stronger domestic corridors are needed before regional trade can reach its full value.
Distribution Networks Remain the Local Weak Point
National generation and transmission receive most public attention, but electricity reaches users through Eskom and municipal distribution networks. In many municipalities, ageing substations, overloaded transformers, cable theft, illegal connections, weak maintenance and poor revenue collection reduce service quality even when the national grid has enough power.
The financial problem is closely connected to the physical one. Municipal arrears owed to Eskom reached about R94 billion by March 2025, placing pressure on local service delivery and Eskom’s balance sheet. When municipalities cannot collect payment or manage electricity revenue effectively, maintenance is delayed and network losses increase.
Eskom’s 2025 results show both progress and the size of the problem. The utility added more than 83,000 electrification connections and recoded 5.6 million active prepaid meters, including around 800,000 smart meters. At the same time, it estimated that 14.9 TWh of electricity was lost through theft. Smart metering, protected equipment, accurate billing and professional maintenance are therefore infrastructure priorities rather than only administrative reforms.
Storage and Reused Coal Sites Can Support the Transition
Grid expansion will work best when combined with flexible generation and storage. Eskom has begun deploying battery systems, including the Hex project near Worcester in the Western Cape. Pumped storage already provides large-scale balancing capacity, while the proposed Tubatse project could add further long-duration storage.
Old coal sites may also become useful transition assets because they already have grid connections, roads, water systems and trained workforces. Solar, wind or storage projects at sites such as Komati, Hendrina and Lethabo can reuse part of this infrastructure and reduce the time required for new connections. Eskom has identified a wider group of renewable projects across its existing power-station footprint.
South Africa’s energy infrastructure is no longer defined only by whether coal plants can produce enough electricity. The decisive issue is whether transmission and distribution construction can keep pace with a changing market. Generation recovery has stabilised the immediate system, but long-term reliability will depend on new grid corridors, financially sustainable local networks, storage and open access for a broader group of power producers.
