This report documents the technology cost assumptions disclosed in the Integrated Resource Plan 2023 (IRP 2023) and compares them to assumptions used in other recent studies of the RSA power system, as well as a number of independent sources.

The publication seeks to:

  1. To assist stakeholders in making informed comment into the IRP 2023 public participation process.
  2. Clarify that our understanding of the assumptions used in the IRP 2023 analysis is correct.
  3. To elicit views from sector experts as to the reasonableness of the assumptions, and particularly the likely path for future cost development in each technology over the short, medium and long term.

An updated log of changes to the spreadsheet is provided below. Please check for any updated versions before referencing this work.


  • 20240202.1 – Initial release
  • 20240202.2 – Corrected currency years in conversion from USD to ZAR in sheets IEA 2023 (India), IEA 2023 (EU) and DNV
    Corrected inflation period for Solar and CSP in PCC sheet.
  • 20240205.1 – Corrected 1h Battery description in sheet IRP 2023
    Correction of CPI values and exchange rates.
  • 20240207.1 – Formatting
  • 2024/02/12 20240212.1 – Correct Labelling of BW in sheet “Actuals”