How storage helps turn gold mines green

This week, BayWa and Suntrace fired up a 30MW solar plant with a 15.4MWh battery storage system at the Fekola gold mine in Mali in west Africa.

The project is set to be 100% operational by the end of June and replace three of six heavy fuel oil generators that help Fekola run 24 hours a day. The solar-and-storage system should also enable mine owner B2Gold to significantly cut production at the three other generators.

The partners said this is the largest off-grid solar-battery hybrid system in use in the global mining sector. Dennis Stansbury, senior vice president at B2Gold, called it a “landmark project” that should “pave the way for more sustainable power generation within the mining industry in West Africa.”

He added it would help improve the environmental credentials and economic viability of the mine, by ensuring that it can run reliably using renewables and cutting the use of 13.1million litres of heavy fuel oil each year.

Fekola is not the only gold mine integrating storage into its energy transition plans, and it is a trend that extends far beyond Africa too.

All that glitters

Yesterday, Juwi Renewable Energy agreed with APA Group to build a 13MW solar component for a solar, gas and battery hybrid solution at the Gruyere Gold Mine in Western Australia. The system includes a 4.4MW / 4.4MWh battery and is due to be commissioned by the end of 2021.

Dave Manning, Director Global Hybrid at Juwi, said it would "help reduce the overall carbon intensity and cost of power supply to Gruyere Gold Mine".

Last year, South African miner Gold Fields and independent power producer EDL completed the second phase of a 56MW microgrid project that means the Agnew Gold Mine in Western Australia can achieve an average 50%-60% renewables in its energy mix each day, and up to 85% some days.

The 23MW first phase of the project completed in 2019 and was made up of nine 2MW gas turbines, two 1.6MW diesel generators, and 10,710 solar panels from Suntech. The second phase was completed in May 2020 and was made up of five Goldwind wind turbines totalling 18MW, and a Saft storage system of 13MW / 4MWh. This is Australia’s largest hybrid renewable energy microgrid.

James Harman, chief executive officer at EDL, said the battery was “critical” to integrating renewables into the energy mix at Agnew Gold Mine.

In addition, Australian gold producer Red 5 announced that it plans to run its King of the Hills gold mine using a 30MW power station made up of gas, a 2MW solar farm and a battery system.

The power plant is set to be run by Zenith Pacific and isn’t on the site of the mine, but it shows there is demand to use energy storage to support the use of renewables at gold mines and in the mining sector more widely.

Golden opportunity

We can see this demand from miners for batteries in a research report, called ‘State of Play: Electrification’, that was published by the University of Western Australia and consultancy VCI in 2020, with partners including the Future Battery Industries Co-operative Research Centre.

This surveyed 450 individuals to find out their biggest priorities as they look to electrify mines and reduce the environmental impact of the mining industry.

Of those surveyed, 57% said the energy transition was the global trend that would have the biggest impact on the mining industry over the next 15 years; 89% expect mines to electrify in the next 20 years; and 61% expect the next generation of mines to be all electric.

Additionally, 83% expect renewables to significantly change mining operations over the next 15 years. If that happens then batteries are a key enabler.

The report also includes interesting insights on storage specifically:

Eighty-seven percent of respondents expect solar to become the most widely-used energy source in the industry in the next 15 years.

Seventy-six percent expect remote mines to use batteries to support renewables, ahead of diesel (53%) and demand management (42%).

Respondents are currently unsure of which energy source will power heavy mobile equipment: 28% expect lithium batteries to do the job, ahead of hybrid systems (21%) and diesel (18%).

Finally, 85% percent said broad industry standards for batteries are required to help support their further rollout in the mining industry. The report predicts more clarity on the best options by 2025.

The report also includes case studies of how firms including Rio Tinto and Oz Minerals are adopting storage at iron ore and nickel mines respectively.

This stands to reason. Mines are major energy users and, like other sectors, are under pressure to become more environmentally friendly. When it comes to understanding storage, gold mines such as Agnew, Fekola and Gruyere can equip miners with vital nuggets of wisdom.