Reducing electricity costs

Submetering reduces electricity costs

At the Rob Ferreira High School in Mbombela (Nelspruit), intelligent submetering of electrical installations has resulted in enhanced visibility of consumed energy. The consequence is an increased focus on energy-guzzling installations. Instead of just measuring the energy consumption as a whole via the main meter and then pay the bill according to tariff, the school chose in cooperation with Livewire to designate smart meters for the school facilities, boiler rooms, girls hostel, boys hostel, residences and vendors in order to gain a clear picture of a very energy consuming installation type.

The result was that heat pumps can be used to heat up the water during daytime, but boilers are kept as backup for peak hours.

Additional metering provides more detailed information on the energy usage with the result that consumption peaks can be reduced and hence peak tariffs avoided.

Anyone wanting to save energy must first know what they consume.

Attie van Jaarsveldt, Managing Director at Livewire Engineering and Consulting, uses a simple formula for the benefits of smart metering: “If you don’t measure, you don’t know, and eventually you are unable to act purposefully.”

The electricity meters and heat meters with different communication modules form the basis of the new metering infrastructure. The metering infrastructure is a combination of 3-phase and 1-phase meters using GPRS and Kamstrup’s Radio Mesh Network with GPRS concentrator/gateway nodes.

The smart meter network interfaces with Livewire’s energy data centre situated in Cape Town.

Here are the energy data being processed, validated and interfaced to the energy billing system and the Liveview Web portal.  With the web portal, load profiles of each facility can be displayed for further analysis, and group reports can be compiled for energy re-allocation and display.

Trust in technology

The smart metering system even turns out to be a capable instrument for handling the complicated South African tariff system.

The detailed picture of the consumption pattern emerging from the frequent readings makes it possible to pin out exactly the right tariff to apply.

The whole idea of implementing intelligence in the energy metering system is to eliminate the human factor and to benefit from more plentiful and more reliable data.