This comes after the Airports Company South Africa commenced construction of a 500 kilowatt peak solar photovoltaic system at each airport.
The two constructions are expected to be completed in June.
ACSA spokesperson Collin Naidoo says: "The decision was informed by Airports Company South Africa to identify and use alternative renewable energy sources.”
Naidoo adds: “Furthermore by producing its own electricity the Airports Company South Africa can save on costs and divert its energy consumption off the severely constrained national grid. The electricity that will be generated at both these airports will be for sole use of the airports."