The Democratic Alliance on Sunday said it was concerned with a lack of clarity about the current state of South Africa's power supply system as the new year took off.

"The power utility and Deputy President Cyril Ramaphosa must... let us know exactly what the current state of affairs is, and what we can expect when the majority of South Africans return to normal business," DA MP Natasha Michael said in a statement.

She said that the public also needed to know what happened on the deadline of December 24 when the first unit of the Medupi power plant situated in Limpopo was meant to become operational.

Additionally, said Michael: "We have yet to be informed exactly what maintenance, if any, was undertaken during the low peak period."

In response to the DA's statement, Eskom warned that from the second week of January, electricity supply would come under strain as schools and businesses re-opened.

"The power system is expected to come under severe strain from then, with a medium to high risk of load shedding," said Eskom in an email.

"However, load shedding will only be used as a measure of last resort in order to protect the power system from a total collapse."

The parastatal also said that the switch-on of the Medupi power station did not take place due to certain technical cleaning processes that were still underway.

A specific date for when this would be completed was not provided.