Eskom blamed the tardy approval process in bringing additional generation capacity to the grid as it imposed the worst rolling power cuts so far this year and warned of up to 100 days of outages for the year ahead in one of the latest reminders of one of the biggest factors hobbling the economy.

Persistent operational and financial problems at Eskom heap pressure on President Cyril Ramaphosa to push through reforms at the utility to lift the economy out of a decade-long downward spiral...