Residential Load Management Project
FACTS AND FICTION ABOUT THE GEYSER IN YOUR HOME
Electrical load is moved from peak to off-peak periods
The Overstrand Municipality joined forces with Eskom to install geyser control units (also known as appliance control devices or load control switches) in the homes of consumers in Hermanus, Kleinmond, Gansbaai, Stanford and Hawston.
This project is known as Residential Load Management (RLM) and assists Eskom and the Overstrand Municipality in transferring the electricity load from peak times (when electricity is expensive and in high demand) to off-peak times (when electricity is cheaper and the demand lower). The total community in this area will benefit from the project through a more even distribution of the electricity load. This in turn will lead to a more reliable electricity supply and the minimisation of power outages during peak times.
What are peak times?
Domestic usage of electricity is at its greatest during peak times, which are normally between 18:00 and 20:00, but during times of high demand can be from 17:00 to 21:00.
Why RLM?
RLM is an important part of the load management component of Eskom’s overall demand side management strategy. The residential sector contributes quite significantly to the strain on the national electricity network, and residential consumers consume more than 17% of the total electricity generated by Eskom daily. Residential consumers contribute up to almost a third of the total electricity demand during peak times.
Why geysers?
Research revealed that geysers are the main culprit when it comes to residential demand. A typical geyser would use about 3kW per hour to reheat water that was already warm – only because the temperature of the water dropped below the predetermined level. A consumer will not even notice the difference between water of 55 and 60 ̊ C, but the thermostat, which is an electromagnetic instrument, will automatically react because of its setting.
A physical audit has been conducted in residential areas as part of the feasibility study to determine the number of geysers in the Overstrand municipal area.
How does it work?
A small control unit or switch is installed next to or inside the electrical distribution board in a home. This device then switches the electricity supply from the geyser to the control unit on and off through a signal. Groups of geysers in specific residential areas can be switched off for a predetermined period to reduce the overall demand at a specific time. Calculations were done to establish for exactly how long an average geyser can be switched off before a typical household would experience a drop in the temperature of the water, and incorporated in the mathematical formula used to determine the duration of the switching.
How does the specific technology work that is implemented in the Overstrand Municipality?
The appliance control device that is implemented in the Overstrand Municipality is the forerunner of the so-called smart meter. These control units are linked to each other by means of a radio signal and form a communications network or cloud. The communication between the units depends on the number of units that are installed: the more, the better.
What about hot water?
The load management system will switch off the electricity supply to the geyser during peak times only. The water stored in the geyser should be sufficient for normal usage even if the power supply is not switched on.
Can I switch off my geyser manually after I have installed a geyser control unit?
If you do switch off your geyser manually in the mornings and back on after returning from work in the afternoon, do so as soon as possible after arriving home to allow the geyser to heat the water sufficiently before the municipal switching is done at 18:00.
How will the unit be installed?
Trained installers, under supervision of qualified electricians, will install the units. These installers, carrying identity cards with the logos of Overstrand Municipality, Eskom and Powertech IST, will visit all homes in Hermanus, Kleinmond, Gansbaai, Stanford and Hawston to install the units.
Where can I obtain more information?
More information is available at the Call Centre, tel 083 228 0268, of visit www.eskomidm.co.za.
Source: Overstrand Municipality