Eskom's warning that South Africa may again experience load-shedding on Thursday evening was a clear sign that the power utility could not be saved, the opposition Democratic Alliance (DA) said on Thursday.

"Eskom's warning today of a heightened risk of blackouts this evening again shows that it is in a death spiral and that it is time for the ANC [African National Congress] government to get out of the electricity generation business and give the power to generate electricity to the people," DA public enterprises spokesperson Ghaleb Cachalia.

He said Eskom was unable to work its way out of billions of rands of debt, consumed bailout cash, and could not recover billions of rands in arrears from consumers. Its infrastructure continued to fail and power generation mix was so archaic that it could not make a necessary shift to renewable energy sources.

"These are signs of an entity which cannot be saved. We maintain that it is in a death spiral, and for so long as the ANC government continues to pretend Eskom can be saved, it is dragging South Africa with it down this spiral."

Cachalia said it was worrying that the company had not tabled a solution to its financial crisis to parliament for oversight or been transparent about its plans for restructuring and operational turnaround while rolling blackouts remained on the cards.

He complained that the DA's requests for an urgent meeting of parliament's portfolio committee on the continuing crisis had gone unheeded, and that public enterprises minister Pravin Gordhan had not responded to a request from the DA for a meeting to discuss a way forward.

Eskom announced on Thursday morning that the national power system was under stress and that it had resorted to burning diesel to meet electricity demand.

"While we have adequate emergency reserves to supplement capacity during the day, we may need to implement load-shedding this evening in order to augment diesel and water at our open cycle gas turbines and pumped storage schemes respectively."

Scheduled power cuts reached unprecedented levels late last year.