Unit 1 of Koeberg Power Station has been shut down for its scheduled refuelling, maintenance and upgrading, Eskom said on Friday.

"The refuelling process is expected to be completed in May 2009," the state-owned power utility said in a statement.

"This outage has been planned for, and the duration factored into the overall generating maintenance plans for all of Eskom's power stations."

While Koeberg Unit 1 was not generating electricity, the Cape would be supplied from Koeberg Unit 2 and from power stations in the north of the country, Eskom said.

To meet the morning and evening peak requirements, additional power plants available in the Cape would be utilised. These included the hydro and pumped-storage units and the two new open-cycle gas turbines — Gourikwa and Ankerlig power stations.

Two more units had recently been commissioned at the Gourikwa power station. This brought to five the number of units that the Gourikwa power station now had.