Eskom puts its own figure on the Kusile and Medupi build, and on a diesel bill that keeps falling.

For a generator holding a power purchase agreement with Eskom, the recorded cost of the utility's two newest coal stations is now a figure Eskom has published itself rather than an outside estimate. Eskom said on 10 September 2026 that Kusile's approved construction budget is unchanged at R160.5 billion, with roughly R155.5 billion spent since the project began, counted to 31 July 2026, and that Medupi's remains R145 billion against roughly R131.1 billion spent, counted to June 2026.

The statement answers accounts in Daily Investor and MyBroadband that put Kusile at R233.4 billion and Medupi at R176 billion. Eskom says it has never carried either as an approved budget or as recorded spend, and that any amount above its approved capital allocations should be labelled an outside estimate.

On the claims book, Eskom points to the Kusile dispute with the Stefanutti Stocks Basil Read joint venture, closed in November 2025 through a Dispute Adjudication Board: a claim of R1.6 billion was settled at R580 million, cutting exposure by over R1 billion.

Both stations are finished as generating plant. Kusile's sixth unit began commercial service on 29 September 2025, completing six units rated together at 4 800MW, and Medupi's last unit did so on 31 July 2021. The close-out date of 31 July 2028 covers defect periods and balance-of-plant work, which Eskom separates from construction. Availability for the financial year to date sits near 90% at Kusile and 85% at Medupi, and the country has run more than 480 days without load shedding. Diesel spend on peaking turbines has dropped across three years: about R33 billion in FY2024, R17.7 billion the next year, then about R7.1 billion, some R25.9 billion less in total.

Read together, these numbers shift the arithmetic a buyer brings to the South African electricity market, because a utility with its newest units running hard and its peaking fuel costs a fraction of their earlier level argues price from firmer ground.

The implication is that the figure to watch is not the contested build total but what Eskom asks NERSA to allow on fuel and capital recovery once these savings sit in the audited record.