Supporting miners to net zero emissions

Rod Saffy, Global Head of Mining, Aggreko

The energy market is undergoing significant change marked by a strong shift to renewable energy, and discerning METS companies are taking significant steps to support miners on their respective journeys toward achieving net zero carbon emissions. Some of the ways these companies have already innovated include:

• Turning waste gas into power • Adding battery storage and solar power to existing fleets • Finding creative ways to reduce generator emissions Some of the renewable power technologies and fuels available today offer the same – if not better – levels of reliability and competitiveness than traditional thermal technology. During the next few years, METS companies will increasingly need to lead by example, setting their own emissions targets (if they have not already), and ensuring their own vehicle fleet and equipment are prepared for the energy evolution of e-fuels, hydrogenready engines and fuel cells. It’s important that investment in new technology is a core part of a company’s values and actions, as new innovations will be critical for the mining industry’s clean energy revolution. The mining industry in Australia is moving forward with its commitments. On October 1, 2021, The Minerals Council of Australia (MCA) confirmed the industry’s ambition to achieve net zero emissions by 2050 in support of the goals of the Paris Agreement – a statement the Queensland Resources Council (QRC) endorsed. The QRC supports the Paris Agreement and its reductions goals to limit global warming to well below 2°C – preferably to 1.5°C – compared to preindustrial levels. Here are just some of the pathways that miners can embark on in the short term to reduce their emission targets. • Remote microgrid for mines Grid connection is not always available as mining companies are forced to push new frontiers of exploration due to scarce resources. To reach those resources, mines are increasingly being established in offgrid locations and their lifecycles can vary, meaning it is no longer always financially viable to build permanent power infrastructures to service the mine. Instead, remote mines are now utilising scalable microgrids that can evolve with the lifecycle, improving flexibility and efficiency. These microgrids also offer an independence from the grid that can often result in a cost-effective solution that doesn’t compromise on reliability. Whether it’s a

thermal, renewable or hybrid, a mine’s power strategy needs to address capacity and how this is likely to change throughout the lifecycle of the mine.

Case study example: Offgrid renewable power station

Aggreko has started construction of an off-grid renewable power station for Gold Fields in Chile at their Salare Norte mine. That station will be about 4,500m above sea level and is located 190km from the nearest town. Our engineers are creating a unique offgrid hybrid power solution, comprising of diesel and solar. We estimate the mine will experience $7.4 million in energy cost savings across the 10 years, which means we have become a major investor and partner at the mine. • Hybrid power plants Hybrid solutions combine renewables with thermal generation and battery storage, and benefit miners in locations with limited or no access to permanent power. Hybrid power plants provide customers with flexible and reliable solutions that are cost competitive. Once solar or wind plants are installed, running costs to generate are relatively low and at zero emissions. But unlike thermal generation, wind and photovoltaic (PV) are variable power sources. Battery storage strengthens a mine’s grid by buffering the impact of fluctuating power demand and supply. At the same time, generators’ lifespans are increased and there is a decrease in costs associated with operations and maintenance (O&M) as they are being run less often and more efficiently. With a modular solution, power can be scaled up or down depending on the mine’s needs.

Case study example: Granny Smith mine

Aggreko has worked closely with Gold Fields at their Granny Smith mine in Western Australia to successfully transition to a renewable energy plant, which at the time included the installation of the biggest offgrid renewable microgrid in the world. Aggreko installed a 28MW gas-fired thermal power station, an 8MW solar farm and a 2MWh battery energy storage system. This was all engineered, procured and constructed by Aggreko and is run as independent power to Gold Fields. • Virtual gas pipelines Gas power generation offers a greener and more costeffective alternative to diesel and heavy fuel oil, however, not every mine has an existing gas pipeline they can leverage. Even where a gas pipeline exists, insufficient supply during peak periods may cause issues. A virtual pipeline is a substitute for a physical pipeline where gas that would typically be conveyed through a conventional gas pipeline is instead transported as LNG or CNG to the point of use by sea, road or rail. Where no gas pipeline or grid connection exists, the gas virtual pipeline enables natural gas to be used as primary fuel for power generation using our modular generators. In addition, a virtual pipeline can provide back-up fuel where natural gas pipeline capacity is limited. For mines that aren’t connected to a physical pipeline and looking to switch to gas from diesel, the 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 as the system is simply using stored natural gas to augment pipeline natural gas and can use the same delivery system.

Case study example: From diesel to virtual gas pipeline

In Western Australia, Aggreko has assisted a miner to move away from diesel without a significant capital outlay. We built a worldclass gas plant at Ora Banda Mining’s Davyhurst Gold Mine, which is about 150km north of Kalgoorlie. The LNG station project helps the miner get closer to its net zero emission targets and uses a virtual pipeline of gas trucked more than 650km. It is expected to slash the miner’s carbon emissions by 25,000 tonnes in the first five years of operation. The power station is highly efficient, scalable and very suitable for transient loads and for the introduction of solar at a later stage. With flexible contracts and no capital outlay for the miner, Aggreko can upgrade the technology and scale the level of power the mine needs as it evolves. We currently operate five virtual gas pipelines on mining projects in Australia (2), Spain (1), Canada (2) and have started commissioning our sixth in Chile. All are about 6-10 MW projects and use LNG or CNG gas trucked over a distance of 500-1000 kilometres.

• Hydrogen Investment in hydrogen as a fuel is on the rise 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. Until recently though, using hydrogen was thought to be

too tricky, risky and expensive for it to really take off as it was challenging to transport and store. That’s all starting to change now, with large-scale investment and growing interest meaning hydrogen is finally on the cusp of becoming truly viable. It’s important not to look at hydrogen as a direct replacement for oil, coal or gas, or a direct competitor to wind and solar, but to find applications where the unique properties of hydrogen give it a technical and commercial fit. Hydrogen also offers a useful alternative source of electricity; one that isn’t subject to the availability issues of weather-dependent renewables like solar and wind. Hydrogen production and refueling can happen around the clock. Fuel cells provide a constant power supply for generators and other equipment. It can also be fed as raw fuel into large-scale engines, creating a way to supply temporary, off-grid power. As the technology improves, powering modular generator units with hydrogen power could allow off-grid users to scale up their local power production into entirely clean, on-site, temporary power plants. All of these suggest exciting possibilities for decentralised power that is not reliant on the grid. Importantly, green hydrogen, or hydrogen fuel created in plants using entirely renewable energy sources, is becoming increasingly viable. Along with efficient hydrogen storage and transportation, this is the only way to ensure hydrogen is considered a sustainable renewable source.

Case study example: Hydrogen

As well as being an energy carrier, hydrogen is used to create several clean-burning, synthetic fuels. We are already able to use hydrogen-based e-fuels within some of our existing fleet and are accelerating our investments in hydrogen technology. Our first hydrogen power generation units, developed in conjunction with our clean technology partners, have been piloted in field trials in the Netherlands. • Other power sources Energy sources likely to become more prevalent in mining in the next few years include:

o Biofuels: Biofuels, including ethanol blended fuels and biodiesel, are made from vegetable and animal products whereas petrol and diesel are made from nonrenewable resources like crude oil. While using biofuels is not new, as technology advances, biofuels are expected to become less expensive and provide a sustainable alternative to fossil fuels. o Wind power: Electricity generated from wind turbines is a source of renewable energy on mining sites. Wind power takes advantage of unused land on mine sites and is used to augment the energy supply when the wind is blowing. o Hydropower: Miners already generate a substantial amount of their energy from hydropower. Further developments in microturbine technologies are likely to provide opportunities to recover energy from gravity flow liquid systems within a mine. This will generate more renewable energy. o Solar energy: Energy generated by the sun is an effective way of integrating renewable energy at mine sites, particularly at mines with large amounts of unused land. o Energy storage: Battery energy storage systems (BESS), pumped storage, and electro-mechanical flywheel energy storage have the potential of being incorporated into a mine’s microgrid. The technologies help to level demand by reducing peak loading and storing excess energy generated from renewables. o Gas: There is an increasing trend for miners running on diesel to convert to gas. There is also no reason why mines cannot add a solar power system, battery storage and wind power, or any other renewable you might find, to the arrangement. Gas generation systems can run with hybrid renewables too. Other new technologies being experimented with across industry include mobile wind solution, re-deployable solar panels, and tidal wave power.

A collaborative future

The world’s reliance on power – particularly renewables – will grow significantly in the next 10-30 years. Investing in long-term power stations will be considered higher risk for mining companies when technology is evolving so rapidly. Increasingly, as mines electrify and need more power, miners are needing energy on their sites provided as a service. Miners are increasingly wanting hybrid solutions which use a combination of power options such as diesel, gas, solar and battery power. They also want that power to be scaled up or down and upgraded as needs change or new technology comes online. For these reasons we are seeing greater collaboration between the energy and mining sectors. Partnering with an energy provider can bring about many benefits. What this might look like is a power company becoming an investment partner at a mine for the whole life of the project, or for part of the project. The energy provider would take care of the power, monitoring and all the technological upgrades as they come online, while the mining company focuses on its core skill which is mining. This type of model de-risks the threat of future innovation and technology for miners and frees up working capital for profitable uses without increasing the debt ratio for mining projects. Modular power also gives miners the ability to leverage innovation at low risk and not be concerned about having sunk capital or ageing equipment. It’s a very exciting time in the mining sector, and it will be amazing to see the innovations presented during the next few years as some of the industry's best minds collaborate for a greener future. 

Increasingly, as mines electrify and need more power, miners are needing energy on their sites provided as a service.