Gold mining company Harmony estimates that it will achieve total cumulative net present value savings of R3.6-billion from its three solar power projects, one of them already generating 30 MW of clean, green energy.

To reduce its carbon footprint, the JSE-listed Harmony, headed by CEO Peter Steenkamp, has been building and commissioning renewable-energy projects at its South African operations since May 2022.

Harmony’s decarbonisation strategy is guiding operations to net-zero greenhouse-gas emissions by 2045 along a transition pathway that includes energy efficiency, portfolio re-engineering, electricity mix, improvement adaptation and decarbonisation of the transportation sector.

Within host communities, Harmony, chaired by Dr Patrice Motsepe, is working with the Federation for a Sustainable Environment to build a resilience to the impacts of climate change.

The savings from the phased introduction of these projects is detailed in Harmony’s latest Environmental Social Governance Report, which shows a total of 223 MW solar power over three phases being augmented by 140 MW of wind power in a fourth phase.

A 30 MW solar plant commissioned for Tshepong, Nyala and Eland in May at a capital cost of R5-billion, is expected to save R340-million over 15 years as it takes 62000 t/y of carbon out of the air.

The construction of the second-phase 137 MW solar project under way for supply to Moab Khotsong, Great Noligwa and Noligwa gold plant in 2025 at a capital cost of R2.5-billion, will save R2.5-billion over 15 years. Capital of R1.7-billion will be invested for the first 100 MW, and the remaining 37 MW will be allocated to an independent power producer to collectively eliminate 4.6-million tonnes of carbon over 25 years.

Funding for Harmony's decarbonisation strategy is facilitated by Rand Merchant Bank, African Clean Energy Developments, African Infrastructure Investment Managers, Mahlako Energy Fund, Absaand Nedbank. The facilities, amounting to R4-billion, include a R1.5-billion green loan for the second phase of the renewable energy programme.

Harmony’s current assets are predominantly deep underground mining operations, which are more energy intensive than surface mines and accountfor 89% of the group’s total electricity consumption in its 2023 financial year. In South Africa, energy accounts for about 19% of operating costs.

Papua New Guinea

More diesel power than grid power is being used at Hidden Valley in Papua New Guinea (PNG) following a drought constrainingPNG Power’s hydropower capacity. Water in Yonki dam, serving the Ramu hydropower station, was critically low for most of the year and smaller run-of-river hydropower plants were also restricted to 30% of normal supply to the Ramu grid. This led to intense loadshedding until the hydropower generation recovered. However, commissioning of the 11.6 MW Baime hydropower plant owned by PNG Forest Products in March augmented PNG Power supply.

In Australia, Harmony is assessing alternative power supply options and mixes for Eva Copper, including the integration of renewables into project design and future opportunities related to the Queensland government’s CopperString project. The May 2020 Eva Copper feasibility study and December 2021 update, prepared before Harmony acquired the copper asset, proposed gas-fired power as the life-of-mine solution for the project. However, in keeping with its climate change commitments, Harmony is revisiting its power source and energy mix as part of a detailed review and optimisation study. Alternative power supply options and mixes are being assessed, including integration of renewables into project design and future opportunities related to the Queensland government’s CopperString project. To understand future power supply options, various stakeholders are being worked with, including the government-owned Powerlink Queensland, which will construct and manage CopperString.

Harmony expects its optimised study to present a life-of-mine strategy that provides reliable power supply to Eva Copper and advances the company’s decarbonisation goals, Mining Weekly can report.