Mining companies are starting to heed the transition towards a low-carbon future by investing in wind energy, solar and gas.
This was relayed at the annual African wind energy summit, the Windaba, in Cape Town, on Wednesday.
Gold Fields VP and group head of carbon and energy Tsakani Mthombeni said the gold miner was gradually transitioning towards a low-carbon and renewable energy environment.
“Ten years ago, you would not have heard anyone talk about renewables in mining, but things are changing. Financiers locally and globally are coming under pressure to be seen to be funding low carbon projects,” Mthombeni told a special session on mining.
This week, Gold Fields became the first mining company in South Africa to publish its first Task Force on Climate-related Financial Disclosures (TFCD) report to improve its disclosure of climate-related information to investors and other stakeholders.
Mthombeni said this had been a significant move in the company’s journey towards managing climate change impacts.
The TFCD is a voluntary disclosure platform led by financial industry regulators and developed as a partnership between industry and users, including financial institutions, investors and stock exchanges.
Mthombeni said that, where possible, gas had been a good transitional source away from diesel on its mines, with gas on site in projects in Ghana and Australia. Gold Fields recently commissioned a 75 km underground gas pipeline in Ghana. This would replace the system of trucking liquefied petroleum gas (LPG) to its mines.
Gold Fields’ Agnew gold mine in Western Australia is to become Australia’s first mining operation to be powered largely by low-carbon and renewable energy. It will combine wind turbines which will deliver 18 MW of power, a 10 000-panel solar farm contributing 4 MW, a battery energy storage system and a 16 MW gas engine power station to underpin supply when required.
Mthombeni lauded the backing of the Australian government, with the Australian Renewable Energy Agency (Arena) contributing the equivalent of $12-million to finance the project.
Gold Fields has also partnered with power company, Aggreko, to install a hybrid solar and battery generation system to provide electricity to its Granny Smith gold mine near Laverton, Western Australia. The proposed hybrid system will consist of a renewable microgrid made of over 20 000 solar panels collectively capable of generating up to 8 MW of electricity, in addition to a two-megawatt battery system for storage.
Mthombeni said several energy challenges faced the global mining industry, including availability of energy, reliability of energy supply, affordability and a need to address the impacts of climate change.
This was amid a tight situation for mining, as mines were getting more remote, deeper, hotter, longer and harder to access.
Mthombeni welcome the imminent release of South Africa’s latest Integrated Resource Plan (IRP) as it would bring a level of certainty and direction.
“When we sink a shaft with a 20-year view, we need to know what our power costs will be, for planning purposes. So releasing the IRP, as imperfect as it may be, solves one big problem. It gives us some short-term view which we can work with. There is some sound direction from government.”
He said that on the technology side, battery storage was improving, with commercial feasibility within a mining setting.
Juwi Renewable Energies project development head Chris Bellingham said complementary solar photovoltaic and wind resources had provided up to 80% renewable energy in its West Australian mining project. Diesel was able to provide good support.
He said renewable energy hybrids would be able to generate grid-connected tariffs at significantly lower rates than that of Eskom’s industrial tariffs.
Meanwhile, Bushveld Energy head of origination and investment Peter Oldacre said vanadium redox flow batteries were becoming an excellent option in stationary storage. He foresees a huge opportunity for South Africa, which has the largest high-grade deposits of vanadium in the world. South Africa also processes most of its vanadium.
Oldacre said a project to demonstrate what vanadium batteries can do in a hybrid mini-grid space, would commission in the third quarter of 2020, which would give it an ideal opportunity to showcase its technology.
“The biggest difference between lithium-ion and palladium competing technologies is that lithium seems to have a better kilowatt-hour pricing structure for short duration cases, whereas palladium works fantastically well on a kilowatt-hour basis once you use it more than four hours a day,” said Oldacre.