The City of Cape Town and the close surrounding municipalities are at a slight advantage to other parts of South Africa when it comes to loadshedding.
At times when Eskom calls for Stage 1 or stage 2 loadshedding nationally, lucky Capetonians can keep the lights on and the fridge running for a little longer (there is still loadshedding, but at times it is greatly reduced or it bypasses Cape Town completely) due to the Steenbras dam and its pumped-storage hydroelectricity power plant.
Nestled high above Gordon’s Bay sits the Steenbras dam and deep under the facility sits the hydroelectrical unit which generates the much needed electricity at times of peak usage or during load shedding.
The very simple system works by holding water in an upper dam and then releasing it to a lower dam through a series of pipes. On its journey to the lower dam the water passes through turbines which is connected to a generator to produce electricity which can then be supplied to the local grid.
During off peak usage times the water is then pumped from the lower dam back up to the higher dam in order for the process to start again.
This method of generating electricity enables storage of electricity and can actually save energy. A huge bonus is that it can also be turned on quickly at peak times or in the case of South Africa, during loadshedding!
Also at Cape Towns disposal is the Roggebaai Gas Turbine and the Athlone Gas Turbine, these can also be used to generate electricity but over much shorter time periods.
These two use much more expensive fuel (Aviation Jet-A1), and after the Steenbras hydroelectric dam has been fully utilised they are not used as much.
Source: Blackland Industries