Storage and gas go first, and wind and solar wait for a second determination.

For a generator holding a wind or solar project and waiting on a capacity allocation, the first determination under the Integrated Resource Plan 2025 will not carry one. The Minister of Electricity and Energy has confirmed the approach proposed for that determination, made under section 34: priority for 4,600 MW of battery energy storage and 5,000 MW of gas-to-power, 9,600 MW in combination, and nothing for new wind or solar. A later determination is to cover those technologies, along with hybrid projects paired with storage, and pumped storage over a longer horizon.

The stated reason is curtailment. Curtailment is what happens when electricity that could have been generated cannot be taken, either because the network is constrained or because supply exceeds demand at that moment: the energy goes unused while the infrastructure and contract costs stay in place. Rising curtailment is adding to system costs, and so the sequence puts better use of the electricity already available ahead of adding more variable output to the South African electricity market.

Two design points matter commercially. Storage is to be matched to when the system operator needs it to charge and to discharge, backed by enforceable availability and performance obligations, with value read off the electricity moved into useful hours. The implication is that a storage owner's revenue will rest on being available when the system operator wants it, not on installed capacity alone.

On the gas side, the design work takes in how fast a plant can start and change output and how low it can run, weighed alongside fuel supply, delivered gas prices, the ports and pipelines behind it, and grid connection and commissioning dates. Affordability is to be judged against how often the plant would actually run.

There is a base to build on. By June 2025 all five projects from the first storage window had closed commercially and begun construction, 513 MW between them, drawing R15.4 billion in investment. The new allocation is about nine times that volume. Read together, the first determination sets the near-term market in storage and flexible gas, and leaves the timing of the next one as the variable a wind or solar developer has to watch.