Cape Town - Eskom has moved from stage 1 to stage 2 load shedding which is expected to continue until 22:00.
"The electricity supply system remains very vulnerable due to a shortage of generation capacity as several units are currently out of service due to planned and unplanned outages," Eskom said in a statement.
"Eskom would like to assure customers that load shedding is implemented as a necessary measure to protect the power system.
"Any additional changes on the already vulnerable and constrained power system could lead to a change in the stage of load shedding at short notice.
"Eskom calls on all customers to reduce the load on the electricity grid by urgently switching off geysers, air conditioners, pool pumps and all non-essential appliances throughout the day, which will reduce electricity demand," the supplier said.