Energy Transition Opportunities In Mining

Figure 1. Aggreko Granny Smith solar farm and gas power station from afar.

Rod Saffy, Aggreko, provides insights on how embracing renewables into a mining operation’s energy mix creates positive impacts on cost and emission savings.

While some miners are embracing decarbonisation and taking steps to lower emissions, others are not sure how to begin their transition to renewable energy. Fortunately, power generation companies are taking significant steps to support miners on their respective paths to net-zero emissions.

For those who are yet to introduce renewables, it is not from a lack of desire to change or from not wanting to achieve a net-zero emission future. It is because with so much information – or in some cases, too little information when it comes to emerging or future technologies – it can be hard to know where to start. They also express concern about whether new innovations are a wise purchase, given that technology could change further down the line.

Luckily, technology is not in the same place as it was five years ago, or even two years ago. Some of the renewable

power technologies available today, combined with thermal generation in a hybrid solution, offer the same – if not better – levels of reliability and competitiveness than traditional thermal technology. While it is of course important that miners weigh up the cost, risks and threat of future new technology, an ideal option to start the renewables journey is to consider a hybrid power solution.

Benefits of hybrid models

If miners are to start with a hybrid power solution – where they can switch in renewables to their power mix, alongside fossil fuels – then their operation is afforded more flexibility to integrate new innovations as they become available, and the power plant can be scaled up and down as needed.

There are also ways to de-risk the threat of future innovation. For example, Aggreko’s approach enables miners to partner with the company for the life of their mine. The company’s engineers design an efficient and cost-effective hybrid power plant, meaning miners are not tied down to one fuel type for their power source. Maintenance is also taken care of, and new technology is introduced as it becomes viable.

Simply put, integrating renewables with a hybrid power plant can result in greater cost-savings and efficiencies for the project, when done correctly.

Case study: Africa

To gain an understanding of cost and emissions savings, one solar and thermal hybrid solution Aggreko delivered for a remote gold mine in Africa resulted in more than 12% savings in fuel (approximately 10 000 l/d) and the contract offered meant the miner did not have to come up with capital to invest in the solar plant.

Case study: Chile

In another project, a hybrid solar and thermal power solution the company is working on for the Salares Norte opencast mine in Chile, at an altitude of 4500 m, is expected to achieve US$7.4 million of energy cost savings over the next decade, as well as a further US$1.1 million in carbon tax offset over the life of the mine. This project is also expected to achieve 104 000 t of carbon emissions savings. The system will surpass the Chilean government’s current environmental standards, as well as Gold Fields’ requirement for a minimum of 20% renewable power generation for mining operations.

Options other than renewables

There are times when renewable power options in a hybrid model is not possible for miners due to site space constraints or weather unpredictability. Aggreko’s engineers have pioneered a new power system that will clean up to 99% of all controlled emissions (carbon monoxide, nitrous oxide, and hydrocarbon) from generator exhaust streams. The 1300 kW ultra-low emissions package is the world’s lowest-emitting temporary power generation system – exceeding the most stringent environmental requirements and ensuring vital business operations can proceed swiftly through the permitting process.

The package works by providing 1300 kW of continuous power output. It features a selective catalyst reducer (SCR) that separates harmful nitrous oxide into nitrogen and an oxygen catalyst that converts carbon monoxide into carbon dioxide in a highly efficient combination.

Emission levels are 90% lower than the next best available technology on the market. The company expects the new technology to revolutionise the way air quality is managed in mining and related sectors, greatly assisting projects on the journey to net-zero.

Decarbonisation pathways – in summary

Decarbonisation energy pathways available to miners currently include:

Hybrid power plants

Hybrid power plants combine renewables (for example solar and wind power) with thermal generation and battery storage, benefiting areas with limited or no access to permanent power. These are generally cost-competitive; once solar or wind plants are installed, their generation running costs are relatively low and at zero emissions.

Virtual gas pipelines

Gas power generation offers a greener and more cost-effective alternative to diesel and heavy fuel oil. A virtual pipeline is a substitute, and an alternative, for a physical pipeline. Gas is instead transported as LNG or CNG to the point of use by sea, road, or rail. For mines not connected to a physical pipeline and looking to switch to gas from diesel, a virtual pipeline model simply imitates their current supply solution. For users who are connected to a gas pipeline but are looking to supplement insufficient or unreliable pipeline capacity, the virtual power plant solution has several advantages over diesel.

Renewable energy

Renewable energy power systems are an effective way of tapping into natural resources to provide power, such as: wind farms, hydro power, and solar. The challenge is their reliability on weather, hence why, if power is interrupted for any reason, it is important to ensure they are backed by batteries or a temporary thermal power solution.

A significant future fuel in this space will be hydrogen. Investment in hydrogen is on the rise too because of the role it can play in supporting a global transition to net-zero. Its versatility and compatibility with existing furnaces, engines and generators make it particularly appealing for the mining industry. Businesses around the world are at the beginning of their hydrogen journeys and need to be supported to find the best ways of integrating it into their operations.

Ultra-low emissions package

When space constraints prevent miners from implementing renewables, another option to consider would be a low-emitting thermal power solution. Aggreko’s solution offers an ultra-low-emitting temporary power generation system, which cleans up to 99% of all controlled emissions (carbon monoxide, nitrous oxide, and hydrocarbon) from generator exhaust streams. Emissions levels are 90% lower than other technologies available on the market.

Figure 2. Aggreko Renewables Project at Bisha Mine in Africa.

Figure 3. Aggreko hybrid power plants combining renewables with battery storage and other sources.

Future energy pathways

Energy sources likely to become more prevalent in mining during the next decade include biofuels (as they become less expensive), hydropower, energy storage (such as pumped, mechanical flywheels), and gas generation which runs with a hybrid renewable system. While they are already increasingly used as power sources now, wind and solar power are expected to gain more momentum. Aggreko is also experimenting with mobile wind solutions, re-deployable solar panels, and tidal wave power (though tidal wave power might not be for the mining industry yet).

Energy providers are also committing to emissions targets and incorporating environmental strategies into their corporate strategies. Aggreko is committed to operating as a net-zero business across all services it provides by 2050. The company will also reduce the amount of fossil diesel fuel used in customer solutions by at least 50%, reduce local air quality emissions of its solutions by 50%, and achieve net-zero across its own business operations by 2030. To achieve these goals, Aggreko is increasingly offering clean technologies, such as battery storage and solar power, as well as prioritising the use of alternative fuels.

It will be fantastic to see the innovations presented in the next few years as collaboration evolves further between miners and energy companies to lower emissions. The key now though is to embrace renewables into the energy mix because, done correctly, cost and emission savings can be greatly reduced without compromising reliability.

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