All Demand Response programmes are driven by incidences of constraints on the national power system; these include:  
 
Instantaneous Demand Response Programme
 
The programme assists the System Operator (SO) to manage sudden changes in the balance between supply and demand. A trip of a generator unit would, for instance, result in a sudden frequency decline, which could place the power system at risk. Customers participating in the programme are required to reduce load in seconds, thereby assisting the System Operator to arrest frequency decline. Read more>>>
 
Supplemental Demand Response Programme
 
The programme assists the System Operator (SO) to increase the daily ancillary reserve and manage system constraints. The System Operator can call on participating customers to reduce load when required. Customers have relatively short notification times. Load reduction must be sustained for the contracted number of hours per event. Read more>>>