This audio is brought to you by Endress and Hauser, a global leader in process and laboratory measurement technology, offering a broad portfolio of instruments, solutions and services for industrial process measurement and automation. By converting excess water pressure into renewable electricity, emissions are reduced, energy efficiency is uplifted and additional value is created from existing mining infrastructure, Harmony Gold strategic lead for climate and integration Mohammed Asmaljee spelt out emphatically at the launch Minerals Council South Africa's inaugural Climate Change Day of Learning, attended by public sector and private sector climate mitigation protagonists. By capturing pressure from chilled water used in underground mining, the Johannesburg Stock Exchange-listed Harmony generates renewable electricity amid the water that travels thousands of metres underground building up pressure naturally for conversion into electricity through hydroelectric turbines. Importantly, this process recovers energy from existing mine infrastructure without additional water consumption. Such energy recovery systems are deployed at Harmony's underground Kusasalethu, Moab Khotsong and Mponeng gold mines, with water continuing through the mine reticulation network ensuring uninterrupted operational use after passing through the turbines. Four Pelton wheel turbines, for example, are supplying electricity directly to Kusasalethu, where a multi-phase hydropower rehabilitation programme has been implemented to improve reliability, performance and monitoring. A Pelton wheel turbine, a type of impulse water turbine invented by Lester Allan Pelton in the 1870s, converts the kinetic energy of moving water into mechanical and electrical power. Seventy gigawatt hours of renewable electricity have been generated since financial year 2024 and 73 000 t of CO2-equivalent (CO₂e) Scope 2 emissions have been avoided, which has improved energy efficiency by recovering otherwise wasted pressure energy. Water temperatures have also been reduced by 1 °C, which has uplifted underground cooling efficiency and lowered cooling demand. "For us, decarbonisation is fundamentally a business challenge. How do we continue to grow our business in both gold and copper while still reducing our emissions," is the question Asmaljee posed, within the context of South Africa advancing towards net zero greenhouse gas (GHG) emissions under the auspices of the Paris Agreement – a stance being taken ahead of COP31, the thirty-first United Nations Climate Change Conference, which is taking place this month in Antalya, Türkiye, from November 9 to 20. "It affects how we think about energy, costs, competitiveness, regulation, and ultimately the long-term resilience of our operations. We are learning as we navigate this complex transition," Asmaljee explained at the event covered by Mining Weekly. Harmony's carbon challenge is driven largely by Scope 2 emissions from electricity bought from State-owned power utility Eskom, and this is a common challenge for deep-level mining in South Africa, where significant electricity is needed for ventilation, cooling, pumping, hoisting, and processing. Though Harmony's Scope 1 emissions are considerably smaller, there are still tremendous opportunities to reduce them through diesel efficiency and other fossil fuel efficiency projects, improved fleet performance, and future electrification. Business growth and portfolio expansion are also influencing the overall emissions of the gold and copper mining company, which owns CSA Copper and Eva Copper in Australia, assets that increase the company's exposure to the critical minerals needed for the green energy transition. Emphasis was placed on growth and decarbonisation needing to happen together. The challenge is to grow while progressively reducing GHG emissions. Up to 2026, Harmony's emissions have remained relatively stable, but from here on, the emissions trajectory is poised to decrease...
