Energy efficiency measures on mine pumping systems — An M&V methodology

The Demand Side Management initiative of Eskom has inspired Energy Service Companies in South Africa to launch energy management projects on large scale. The mining industry has been one of the greatest targets for these projects. At first, Energy Service Companies concentrated on load management. More recently Energy Service Companies have started to implement energy efficiency projects. The project considered for this article focused specifically on energy efficiency of a mine´s cold water pumping system. The main aim was to match the demand and supply of cold water with each other. This would be achieved by optimising the pressure set point profile of the pumping system and fixing leaks that appeared in the piping system. Energy Service Companies can only claim the incentive from Eskom if they have proof of the savings. Eskom requires that savings must be quantified and verified by an independent third party. This independent third party is known as Measurement and Verification. The greatest challenge in quantifying the exact savings of a project, is finding an independent parameter unaffected by the project. This independent parameter is what drives the energy usage of the system. Any system that consumes energy must have an energy driver. An energy efficiency project usually change all the parameters of a system. Usually the parameters that do not change, can´t be measured. Even if it can be measured, the accuracy of the measurements might be uncertain. This paper will describe how the independent parameter was identified and used to quantify the savings achieved by an energy efficiency pumping project.