Indebted State-owned power utility expects running costs for its diesel-fed turbines, which are used to keep the lights on when coal-powered plants break down, to surge as it struggles to keep up with maintenance. Eskom Holdings sees about a third of its coal-fired capacity being unavailable at any one time under a most likely scenario, it said last week in a presentation to the National Economic Development and Labour Council, which groups business, government and labor union representatives. That would require it to spend R20.9-billion on fueling its open-cycle gas turbines in the 13 months through April next year, or almost three times what it spent in the financial year ended March last year.