Johannesburg - The power system is severely constrained due to unforeseen technical problems at power stations on Thursday, Eskom said.

“Should we experience further technical problems, we may need to implement load-shedding,” Eskom said in a statement.

“Eskom calls on consumers to urgently switch off geysers, air conditioners, pool pumps and all non-essential appliances this evening from 5pm to 9pm to prevent the need for rotational load-shedding.”

As workers left offices on Thursday evening, Eskom asked that they switch off the lights, with the exception of security lighting and avoid leaving on air-conditioning overnight.

Eskom's load-shedding schedules were available for its direct customers on its website.

Customers could also contact their call centre for additional information.

“Load-shedding schedules will only be utilised for the duration of the constraint and Eskom will provide regular updates on the status of the power system,” the utility said.

Earlier this month a coal storage silo at the Majuba power station in Mpumalanga collapsed, resulting in widespread power cuts. The silo held more than 10 000 tons of coal and affected coal supplies to all six units at the power station.

An investigation into the collapsed silo is underway. - Sapa