A method for accurate electricity budget cost calculations for a deep mine

Electricity accounts for a significant portion of the total operating cost of many industries. It is therefore important for companies to accurately estimate future electricity cost. The increasing electricity tariffs greatly affect the consumers in South Africa. The annual active energy cost on an Eskom Megatlex tariff structure is 465% higher in 2015 than it was in 2007. It is therefore important for industries to measure and compare their daily electricity cost to an accurate electricity cost budget. Accurate cost budgeting is also a vital part of energy management. However, the electricity budgets that some consumers select are often over-simplified and can lead to misperceptions regarding system performance. A new method to calculate electricity budgets was therefore developed. This method uses additional parameters to calculate the electricity cost budgets. The most important parameter is time-of-use. The method is also expanded to calculate accurate cost budgets for sub-systems. A case study was conducted on a South African gold mine to analyse the performance and accuracy of the new method. The current method used by some consumers is also analysed and compared to this new method. For this case study the new method was 19 times more accurate than the method used by the consumer. This method uses a specific technique to calculate the electricity usage budget. Other techniques can be explored which might be more effective for different industries.