Andre de Ruyter, the outgoing CEO said on Thursday (December 15) that a lack of political support had made his position "untenable."
He added that his role was dependent on the support of the broader political economy but did not specify in what ways politicians had failed to support him.
The comments came a day after the company announced his resignation, marking the 11th boss to have left the company in just over a decade.
Eskom has struggled for years to meet electricity demand in Africa's most industrialized country.
This year the most electricity has been shed from the national grid to date.
The utility ramped up scheduled power cuts a week ago to "Stage 6," repeating the worst outage level on record.
It means at least six hours a day without power for most South Africans.
These power outages have led to public frustration, damaged businesses and prompted calls for resignations at Eskom.
President Cyril Ramaphosa has been trying reform Eskom to make it more efficient since becoming head of state in 2018, but his administration has made slow progress.
De Ruyter officially became CEO at Eskom in January 2020 moving from packaging company Nampak.
He had also spent more than 20 years with petrochemicals group Sasol in several senior roles.
De Ruyter's last day will be March 31.
