The electricity that’s generated in the power stations is sent over high voltage power lines to the load centres situated in Gauteng, the Western Cape and KwaZulu Natal.

As it leaves the power station, the electricity is boosted by a step-up transformer to voltages such as 132 000 volts (132 kV), 400 kV or 765 kV. When the electricity reaches its destination it’s “stepped-down” to voltages used for distribution.

Eskom’s National Control Centre carries the responsibility of matching supply and demand and has strategies at hand when demand doesn’t match supply. When there’s more power than needed, they instruct the pumped storage schemes to pump water up to high-level dams in readiness for the next surge in demand.

When there’s not enough power they instruct ‘peaking’ stations like gas turbines and pumped storage schemes to add their contribution.

Load shedding is seen as a last resort.