A system for continuous energy management to improve cement plant profitability

Abstract

Until 1996, the price of cement in South Africa was controlled by the government and a legal cartel, whereafter the industry became competitive. Today, new local entrants and increased international competition are placing strain on the oversupplied market. This, in combination with rising energy costs drive cement plants to focus more on the energy and cost effectiveness of their operations in order to be more competitive. A number of energy management methods were investigated as part of the literature review, and it was found that these methods often require large capital investments. This study, however, used different strategies from literature to develop an electricity management system for improving cement plant profitability at a lower implementation cost. The automated specialised electricity management system uses the “plan-do-check-act” (PDCA) approach of the ISO 50001 energy management framework to provide feedback and create awareness on cement plants. The system was developed in such a way that after investigating a plant and its data sources in detail, automated electricity performance reports are compiled. The system uses raw data captured from various sources and translates it into valuable information and graphs. This makes it possible to identify the largest electricity-consuming systems, monitor the performance of the equipment and compare it with continuously updating benchmarks. Specifically developed methods enable the system to identify missed saving opportunities and potential risks, which are reported to the relevant personnel. The system was verified by continuously comparing it with the PDCA approach during the development process. Additionally, a self-assessment ISO 50001 checklist was used to determine to what extent the system contributes toward ISO 50001 compliance. Final verification was done by means of qualitative consultations with personnel involved in cement plant energy management. As validation of the methodology, the system was implemented on a South African cement plant. The quantitative effect was evaluated over 14 months, which indicated that an electrical energy saving of about R4.8 million per annum is possible if performance is maintained. Qualitative studies further confirmed that the system also promotes the implementation of ISO 50001. The system makes it possible to monitor the energy performance of plant equipment and continuously improve operations. This study thus proved that cement plant profitability can be improved with minimum capital investment by using an energy management system.