Saving energy in electrical distribution networks

By Mario Kuisis and John F Kotze, Martec


Download full article

Published in:

Energy Efficiency Made Simple Vol III: Energy and enviroFiciency
November 2012 - Chapter 5: pages 58 - 62

Enquiries: email or


Energy has become extremely costly and all predictions indicate that the rise in cost for this commodity will continue long into the foreseeable future. Energy losses in electrical distribution networks are primarily created by current flowing through the various components that make up the network. The largest single loss is found in the low voltage cables where the highest current flows. The flow of these high currents cannot be eliminated; however, the losses can be drastically reduced by shortening the cable lengths.

Incorporating cast resin transformers into the design of electrical distribution networks will not only reduce the energy losses but also the installation costs. The worked example illustrated the placement of one transformer closer to the load. When a factory has more than one load centre, the possibility of placing two or more smaller cast resin transformers in strategic positions exists with even more savings. The anti-vibration pads, that is standard on all cast resin transformers, allows for them to be placed virtually in any location without harmful effects to the structure due to vibration.


Take note

  • The first transformers developed were air cooled dry type transformers - simple in design and adequate for the low voltages employed.
  • Higher voltages that grew with higher ratings led to the introduction of the oil-filled transformer which, with improved cooling, could withstand the higher voltages; it remains the standard for large power transformers.
  • As oil introduces the risk of fire and explosions, a radical re-design was initiated which led to the development of the cast resin dry type transformer.