In this opinion article, energy analyst and commentator Clyde Mallinson warns that, against the backdrop of persistent and erratic loadshedding, the economic cost of shutting the Koeberg nuclear plant for the extended maintenance that is scheduled to begin within days could be R622-billion, or higher. Having raised these concerns directly in a letter* to the new Eskom board, Mallinson outlines in this article how he has arrived at this cost calculation.