Cost effective management strategies of platinum mine cooling systems

Electricity plays a big role in the rising operation costs within the South African platinum mining sector. Mining companies have to minimise costs. Refrigeration systems are one of the systems that consume the most electricity on a platinum mine and thus a prominent target for energy saving strategies. incentive programmes previously provided crucial financial support for implementing energy saving projects. Recently Eskom's Integrated Demand Management (IDM) funding has become constricted under new DSM contract specifications. A need exists for ESCos to implement new, more cost effective, strategies. Investigations were done on existing load management strategies that included load shifting, load clipping and energy efficiency through control strategies. in this study, a mine layout, system specification, cooling requirements and operations were evaluated and a simulation model was developed together with a cost effective control and monitoring strategy. The strategy was then simulated and showed favourable results. The strategy was implemented on the cooling system by using existing infrastructure and labour. Savings were then achieved by switching off the main energy-consuming components during Eskom's evening peak period (18:00-20:00). The mine achieved energy savings and an energy cost reduction without high implementation costs. The implementation period was also short and no funding was required. An average demand reduction of 4 MW was achieved with an estimated annual cost saving of R1.5 million. The study proves that cost effective energy savings, via manual control and monitoring, can be achieved on platinum mine refrigeration systems. However, although manual control and monitoring require low implementation costs, automated DSM projects are more reliable and sustainable. Manual control and monitoring are short-term alternatives for when the client or ESCo are not able to afford the implementation of automated DSM projects or do not have the initial funding available.