Water supply energy recovery systems on deep mines

In deep level mining, which can reach depths of more than 4,000 m, water reticulation is one of the primary consumers of electricity. Cold water is distributed underground for cooling and services and then pumped back to surface. Systems such as the three chamber pipe system (3-CPS), turbine-pump and turbine-generator systems are installed to recover part of the energy of the water delivered to the underground operational areas. This energy is either converted into electricity or used to dewater the mine. The object of this paper is to investigate the true effect of these energy efficient configurations. The capital cost of implementing more efficient system configurations is usually substantially more expensive. It was also found that the effect of utilisation and the related factors play a major part on the savings realised by the energy recovery systems.