In this Q&A session Joseph Mahendran, Regional Director – Sub Saharan Africa, talks about how to achieve more sustainable mining operations.

Provide an overview of the mining industry’s biggest concerns or challenges regarding energy.

Mining operations are highly energy intensive, with energy representing one of the sector’s biggest operational costs. Depending on the mine location, access to reliable supply may not be possible. Load shedding, for example, in some developing countries can pose a significant risk, directly impacting production.

Currently, whether energy demand is met from the grid or onsite, fossil fuels remain the primary feedstock. This leaves miners exposed to volatile gas, oil and coal prices. The overarching challenge, however, is decarbonisation. Miners recognize the need to decarbonize operations as part of global efforts to mitigate the causes and effects of climate change. Mining is currently responsible for 4 to 7 percent of greenhouse-gas (GHG) emissions globally; and the sector is under increasing pressure from governments, investors, and society to reduce emissions. Operating licenses may be at risk for companies who do not sufficiently cut their carbon emissions.

In response, in October 2021, members of the International Council on Mining and Metals made a collective commitment to net zero scope one (direct) and two (indirect) greenhouse gas emissions by 2050. This is in addition to earlier commitments by companies like BHP and Vale which have since 2020 been targeting a 30 percent reduction in scope one and two emissions by 2030; Rio Tinto is targeting 15 percent. 

Elaborate on how the aforementioned challenges can be mitigated or addressed.

Although decarbonization is the end goal, there is no one-size fits all approach; miners have multiple options and a suite of technologies from which to choose. No one single technology works equally well in all mines, in all regions.

Some common approaches exist, however:

• Using more renewable energy; which has primarily been taking the form of green Power Purchase Agreements (PPAs) for grid-connected mines and creation of onsite renewable energy infrastructure at remote mines.
• For activities such as smelting, where high temperatures are required, green hydrogen can serve as a feedstock, to replace coal and natural gas. Currently the element offers the only way to reach the temperatures required for smelting in a low-carbon manner.  When burning in air, hydrogen can hit 2,000-2,100 °C, similar to natural gas at circa 1,950 °C. When mixed with oxygen to create oxyhydrogen, maximum temperatures can reach 2,800 °C. This broad operating temperature range makes green hydrogen an attractive fuel option for many high temperature processes. Green hydrogen steel and cement plants are now in operation in Europe.
• Improvements in operational efficiency can also reduce GHG emissions by reducing overall energy consumption. Efficiency solutions can range from digitalization of operations, in order to better manage energy usage, to a focus on more efficient equipment that can deliver longer-term savings in the form of reduced energy consumption.
• Water and wastewater treatment and carriage is energy hungry. Comprehensive water management plans that cut levels of consumption, treatment and carriage – reducing evaporation, leaks and waste for example - will reduce energy requirements and, correspondingly, GHG emissions.
• Seeking supply chain partners and OEMs equally committed to decarbonization will help scope 2 emissions; for instance working with steel and cement suppliers who are adopting renewables and green hydrogen in their production processes. The number of such companies is limited but increasingly rapidly.
• Creating zero emissions mobile equipment fleet using a mix of electric vehicles, hydrogen fuel cell electric vehicles or using bio or synfuels. Anglo American, for example is planning to roll out hydrogen fuel-cell and battery hybrid trucks across its global fleet from 2024. The company is currently assessing a two-megawatt pilot truck in South Africa.

Discuss how generating power at mine sites, in particular renewable energy sources, can positively impact mines, particularly in areas with unreliable electricity supply.

Onsite generation of power using renewables main benefit will be in helping miners achieve their carbon reductions targets, by placing miners in direct control of their emissions and other environmental impacts. Onsite renewable energy can help cut emissions not only by powering mine processes but also by charging batteries - or powering electrolysis to create hydrogen – for use in zero emission mobile equipment.

In addition, onsite generation using renewables can reduce long-term operational costs, as well as helping protect mining operations against unreliable grid supplies, by creating an independent power supply.

What challenges are associated with the aforementioned renewable energy sources?

Intermittency is the challenge currently facing miners seeking to generate onsite renewable energy. Photovoltaic solar panels only work during the day, and are most efficient on clear days. Wind turbines can generate power day and night, but only if the wind is blowing. Combining the two in a microgrid offsets intermittency to a degree, but the addition of energy storage is vital.

Low-cost lithium-ion batteries have achieved dominance in daily cycling scenarios where charging and discharging rates provide four to eight hours of backup. Beyond eight hours, the limitations of lithium-ion chemistry come into play, as do the yet perfected chemistries of other battery technologies.

Green hydrogen, produced from the electrolysis of water powered by renewable energy, can provide essentially infinite duration storage and backup power limited only by storage capacity. In tandem with batteries, hydrogen can be there when it is needed, much like the natural gas or diesel backups in use today.

Bringing batteries and hydrogen together can solve intermittency in a fast, economical manner. Hydrogen can serve as a reliable, low-cost alternative to batteries, particularly when considering the forecasted costs, with hydrogen prices becoming more competitive going forward. For more information on the economics and applications of hydrogen read our Hydrogen Market Dynamics ebook.

Elaborate on the importance of integrating decarbonisation methods at mine sites, particularly in developing countries or regions.

No single activity will achieve net zero mining. A combination of the steps outlined above needs to be adopted. For this to be effective concrete steps need to be planned and integrated as part of a decarbonization roadmap. The quality of miners’ initial strategic decarbonization roadmaps will have one of the most significant impacts upon the return on their net zero investments and ability to compete and thrive in a decarbonized future. Below is an outline of what a decarbonisation roadmap requires, for a more detailed explanation look at our Roadmap to Net Zero ebook.

• Decarbonization is a long-term undertaking — looking potentially up to 30 years into the future. To help manage this, the roadmap will need to identify low-hanging fruit and also accept uncertainty. Adaptability has to be built into the plan.
• Decarbonization programs at all levels require an understanding of how legacy, new and soon-to-emerge technologies play together. A decarbonization strategic roadmap that lacks a detailed technology core will be insufficient.
• Establishing which decarbonization technologies are best suited to delivering a miners’ decarbonization goals is inextricably interdependent on factors such as developing an understanding of organizational change and the relevant regulatory landscape. None of these elements in isolation will give rise to an effective strategic decarbonization roadmap; integration is essential.
• Roadmaps need to incorporate commercially ready and emerging technologies available over the next 30 years. This requires the technical competence and in-depth knowledge to identify technology timelines, cost curves, resiliency characteristics and prioritize technologies across multiple factors such as cost and returns, risk, availability and opportunity to scale.
• Accurate data gathering is required to develop the base case assumptions that will be reflected in the roadmap. Initial data gathering includes assessing the organization’s supply and/or demand-side energy production/consumption and CO2 equivalent emissions. This needs to be mapped to an assessment of the organization’s existing and future consumption activities and generating resources – including owned generation or power purchase agreements. The assessment also has to incorporate the organization’s fuel price projections and CAPEX and OPEX estimates.

Discuss the decarbonisation methods best suited to mines.

In addition to the methods outlined in questions 2, 4 and 5; carbon capture systems are a consideration, although these involve the management of GHGs rather than ceasing their generation. In the future, advanced small nuclear power systems will also become worthwhile considerations.

Apart from lowering carbon emissions, what other benefits do decarbonisation solutions create.

Some of the additional benefits are discussed in response to question three. As well as reducing GHG emissions, however, adopting low-carbon solutions can offer new opportunities for local economies. Hydrogen, for example, offers great promise as a way to reduce mining’s scope 1 and 2 emissions. In South Africa the government - through the Hydrogen South Africa (HySA) initiative - is working to expand local knowledge and innovation in hydrogen technology to bring about, among other things, job creation and increased wealth.

Elaborate on the process Black & Veatch has to assist clients to remove carbon from their mine operations. Provide an example of a project that Black & Veatch has worked on in the past six months with reference to how it has impacted the overall mine operation.

A holistic approach is central to the way we can help miners decarbonise. Black & Veatch’s business was founded on two pillars of mining operations, power and water. We understand the fundamentals of both. Decarbonization has been at the heart of what we do for decades - through renewable energy, CO2 capture and zero-emission vehicle infrastructure; in addition to helping develop the roadmaps at the core of a successful decarbonisation strategy. In addition, we are able to support decarbonisation at every point in the asset lifecycle, and minimise risk at the complex interfaces between different technologies and elements of project development.

Among the many ways in which Black & Veatch is helping the mining industry decarbonise is  through a new low-emission mobile equipment project. The multi-site project, still in its initial phases, has the goal of developing and implementing a green hydrogen production and refueling system to power trucks, buses, and other light duty vehicles.

A published version of this interview is available on Creamer Media’s Mining Weekly click here to read it.