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1. What is IDM

In response to the energy challenges facing South Africa, Eskom has established an Integrated Demand Management (IDM) division. IDM is dedicated to ensuring short-term security of electricity supply through coordinating and consolidating the various initiatives aimed at optimising energy use and balancing electricity supply and demand. A key aspect of this demand side management programme is the promotion and implementation of more energy-efficient technologies, processes and behaviours amongst all consumers.

A central focus of IDM is a series of large-scale Demand Side Management programmes. One of these is called Demand Reduction (DR) where the system operator pays customers to reduce load on instruction to balance demand and supply.

Residential Load Management is one of the programmes that are currently implemented by IDM.

2. What does the Residential Load Management mean / entail?

Residential Load Management is aimed specifically at the residential sector, in other words, consumers at home. Geysers account for between 30% and 50% of the electricity consumption in a household and they are therefore currently the focus of RLM. RLM involves the connection of ripple control units (or relays) to geysers, allowing them to be switched on and off by remote control.

3. Why do we need this programme?

Eskom’s residential customers consume around 17,5% of the total electricity generated, with their demand at peak periods amounting to over 30%. Helping residential customers to manage their electricity requirements better will have a significant impact on the overall demand for energy, while also achieving cost benefits for the consumer.

4. How does it work?

A small control unit (relay) is installed in the home of the customer. This unit will switch off the supply to the geyser during peak demand periods for a predetermined period. Groups of geysers will be controlled and monitored centrally from the local Municipal Energy Centre by means of a radio or/and ripple based communication system. The Centre will also take care of all customer queries.

5. Will I still be able draw hot water from the geyser when it is switched off?

The load control system will switch off the power supply to the geyser only during peak periods. Even when the power has been switched off, the water stored in the geyser should be sufficiently hot to cater for normal water usage.

6. What are the advantages of a remote-controlled relay system?

The temperature of a geyser is normally controlled by a thermostat. The thermostat continually switches the heating element on and off depending on the amount of water that must be heated. The relay system switches the heating element off during times when the electricity consumption of the country is high.

7. What does the Residential Load Management (RLM) team need from me?

A qualified electrician from an Energy Services Company (ESCo) will require access to each home in order to install the relay enclosures. Properly identified people will do the work. Please do not provide access to persons not in possession of authentic identification.

8. How do I benefit?

  • The system will help to reduce the peak electrical load at times of maximum demand
  • Expansion of the generation, transmission and distribution system networks will not be necessary in the short term.
  • The need to operate costly hydro-electrical or gas plants to cater for these peak periods is eliminated
  • Implementing the system will help to reduce tariff increases to a minimum.

9. How does the municipality benefit?

If the municipality does not have to upgrade its electricity supply systems to accommodate higher consumption at peak periods, then the costs associated with these upgrades will not be passed onto the consumers. It will also lead to better management and optimisation of current infrastructure to improve service delivery to customers.

10. Who is responsible for the installation of the system?

Eskom finances the capital and operational costs of the system with the costs being recovered by way of savings through network expansion and better utilization of generating capacity.

11. What about security?

Electricians authorised to carry out the installation of the control systems will be issued with appropriate identity cards; householders should demand that anybody claiming to be an electricians working for or on behalf of Eskom should produce his or her card before entering the property.

12. What happens if the relay is faulty and who is responsible for maintenance?

If the relay should develop a fault, it will be the responsibility of the Municipality together with a preferred contractor (ESCo) to repair or replace it. The consumer will not have to bear the costs of repairs or replacement.

13. What is a megawatt?

A megawatt (abbreviation – MW) is a unit of power equal to 1 million watts. A typical household geyser uses between 2 kW and 3 kW of power. In other words, if 500 geysers, each 2 kW, are on, they will consume 1 MW.