A group of around 30 people disrupted Nersa's public hearings into Eskom's proposed tariff increase in Durban on Friday.
Moments before the end of proceedings, they held up placards with slogans including "Eskom you are greedy" and "Stop the coal use" and shouted "Eskom must fall".
One of the protesters, Bongani Mthembu, said the hearings were being held in the middle of the day at the International Convention Centre, which was unfair to those living in townships and those working.
"There are hundreds of townships in this country that still require electrification, yet they are expecting us to come to this big venue and voice our concerns. It is expensive for us to come here. This is unfair and Eskom deserves no increase at all. They must sort themselves out on their own."
Another protester, Esther Klopper, 66, said she had had no electricity in her home for two weeks as she could not afford it.
"My daughter is sickly and is in and out of hospital and I am a pensioner. I get too tired and cannot work. There is no way I support an electricity increase. That is out of the question. These people need to think about us and how we live."
Public hearings into Eskom's application to recoup R22.8bn in costs have taken place in Port Elizabeth and Cape Town.
If Eskom's application was successful, electricity tariffs could rise by up to 16%.
Eskom had given assurances that the lights would stay on, even if the National Energy Regulator of SA turned its application down.