There is a high risk that power cuts may be implemented on Tuesday, Eskom said.

"The system is constrained and the risk of load shedding is high. We will update consumers at a later stage on when the load shedding might begin," spokesperson Khulu Phasiwe said.

Beeld reported that Eskom's decision to shut down Unit 1 of the Koeberg power station on Sunday had cost the economy R7.5-billion rand, according to an energy specialist.

According to Beeld, Phasiwe had said workers erecting scaffolding on Sunday, to prepare for maintenance planned for the week, had accidentally touched the main generator transformer at Unit 1.

This had caused a limited earth fault and the reactor had to be shut down immediately to prevent it burning out, Phasiwe reportedly said.

As a result Eskom had to start up its gas turbines, which run on diesel, to make up the 900 MW, Beeld reported.

The economy suffered a loss of about R7.5-billion because Eskom had to implement Phase two of power cuts the following day on Monday morning, Beeld reported.

Phasiwe said on Tuesday he could not comment on the financial impact of shutting the unit down.

"That is what they say. From our side we are concerned with the technical aspect. We cannot comment about the cost [on the] economy.

"We as Eskom would not wilfully switch off our generators to cause any harm on the economy. When we switch them off it is because there are technical faults we can attend to and fix."