Eskom has published the highly anticipated curtailment addendum to its generation connection capacity assessment (GCCA 2025). The addendum will allow for wind generation from the Western Cape and Eastern Cape to be connected to the grid “almost immediately”.

3 470MW of additional grid capacity will be made available, 2 680MW in the Western Cape and 790MW in the Eastern Cape. This additional capacity, however, comes at the price of curtailment. Eskom’s Transmission Group Executive, Segomoco Scheppers, said in a statement that renewable energy plants will need to accept a “reasonable share of no more than 10% curtailment”.

The company explained that, “as indicated per the GCCA 2025 published in October 2023, parts of the transmission network located in the most favourable areas for wind generation such as the Eastern and Western Cape, have no capacity, as all of the capacity has been depleted from previous bid window rounds and private off-takers.”

In response to this obstacle to renewable energy transmission, the curtailment framework was developed in an assessment by Eskom, German operator 50Hertz and Belgian operator Elia which took place before the publishing of the GCCA in October last year. This framework did not, however, appear in the GCCA 2025, due to pending approval from Nersa.

The addendum stated that unlocking the grid capacity without utilising curtailment would take significant investment and several years to develop. The implementation of curtailment has passed through the necessary government processes and can now be implemented.

The GCCA 2025 Addendum has been published on the Eskom website and can be accessed by clicking on the following link: Generation-Connection-Capacity-Assessment-GCCA-2025-Addendum_Final_20240126r0.pdf (eskom.co.za)