Eskom transforms inputs from the natural environment - coal, nuclear, fuel, diesel, water, and wind - into more than 90% of the energy supplied to a wide range of customers in South Africa and the Southern African Development Community (SADC) region. To balance electricity supply and demand in real time, the System Operator (soon to be the Independent Transmission and System Market Operator, ITSMO, as the Transmission business continues to legally separate) must maintain the frequency of the power system at 50Hz.

Eskom is one of the few remaining vertically integrated utilities connected to the Southern African Power Pool (SAPP) through an interconnected grid, which serves to support grid stability. Eskom relies on SADC members to maintain sufficient and reliable transmission grids in their countries.