Energy monitoring in South Africa

Submitted by: Amanda Botes, Tuesday, April 17, 2012

Many businesses and homeowners are not aware of the amount of energy that they use and are misinformed about what consumes the most energy.  Better energy monitoring of consumption addresses this problem by helping to identify peaks in energy consumption, which devices are drawing the most energy and measuring the effectiveness of energy conservation actions.

 

Types of energy monitors

The type of energy monitor that a user selects depends on the size and needs of the business or household. Larger businesses that operate from multiple sites and that want to coordinate their energy consumption may invest in hiring a company to undertake energy monitoring on their behalf. This can be costly so for small businesses and homeowners investing in a wireless home energy monitor is a more cost effective solution.

Energy monitoring for small businesses and homeowners

There are three broad categories of wireless energy monitoring devices that are available for small businesses and homeowners in South Africa: Display only monitors, Display monitors with download option via USB, and, Display monitors with a downloadable option via the internet. It must be noted that these monitors will not work for some of the larger three phase systems. Before purchasing a wireless monitor for a three phase system, check with the supplier the maximum Amps per phase that can be accomodated.   

All these wireless energy monitors have the following common components as shown in the image below:

  • CT sensor unit: This unit is clipped onto your electricity metre’s feed cable. (For three phase installations two extra CT clamps are required. In addition systems over 90 Amps are likely to require larger CT clamps.  Wireless energy monitors are generally not suitable for three phase systems over 120 Amps.)
  • Transmitter unit : This unit links to the sensor cable and sends information to the display unit
  • Display unit: This unit displays the information on energy usage. Most models display energy used at that particular moment (the recording is taken approximately every six seconds), the amount of carbon emissions emitted as a result of your energy usage, and the cost of the energy in monetary units being consumed.The basic components of an energy monitor
 

The monitors differ in their ability to record the energy data over a period of time and to make the data accessible to multiple users.

1.            Display only monitors

Display only monitors enable the user to monitor usage of electricity by displaying the total energy that is being consumed at any given moment on a display monitor. Users can also view historical energy use on the display unit.  This type of monitor does not allow the user to track or view their energy usage over a long period of time because of limitations on how much data can be stored by the display unit.

Models in South Africa include the Efergy Elite and the Eco-Eye ECM. Prices range from R550-R850.

This category of monitor provides users with current energy consumption information, but does not allow a user to conduct detailed analysis on consumption trends.

2.            Display monitors with download option via USB

Display monitors with download option via USB allow users to connect their energy display monitor to a computer via USB.  These monitors come with software for downloading and analysing the energy monitoring data.  Using the software energy consumption can be monitored over long periods of time and graphs can be generated that demonstrate energy usage trends. The software allows for daily, weekly and monthly comparisons to be made.

In South Africa common options are the Efergy e2, the Owl wireless electricity monitor, the Eco-eye real time electricity monitor ECE and the Wattson. Prices range from R899-R2000 depending on the model.

This category of monitors enables users to monitor energy use over a long period of time and analyse energy consumption information.

3.            Display monitors with an option to upload via the internet

This category of wireless energy monitors allows users to connect to the internet and upload the data automatically in real time.  The display unit is linked to an ADSL modem via a web bridge and the data is automatically uploaded to a website via the bridge. This option enables the user to obtain live information on total energy consumption from the household or office anywhere at any time and share this information with colleagues or household members via the website.  In South Africa the Current Cost CC128 Energy Monitor can be bought with a web bridge. The price of the Current Cost Metre is R800 and the bridge is an extra R550.

Users who are often away from the home or office would find this option useful as energy data is automatically uploaded and may be shared online and accessed remotely.

Energy monitoring for larger businesses

Some larger businesses hire the services of an energy monitoring company. The energy monitoring company installs metres, which are usually rented out to the client, and a monthly maintenance fee is charged.   The energy data is automatically uploaded onto a website that the energy monitoring company maintains. The website capabilities are more sophisticated than websites provided by wireless energy monitors and energy from multiple sites can be monitored and compared. Information can also be shared with colleagues.

This option is the mostly costly energy monitoring solution because there is an initial installation fee plus an on-going monthly fee and is recommended for large businesses and organisations that have multiple sites.

Amanda Botes