Low-carbon energy solutions for mine sites

Mining is evolving to respond. The spotlight is now on using renewable energy and energy-efficient technologies to ease carbon impact. Global supply chains are increasing demands to source critical minerals with low-carbon profiles. And the sector’s investors want to fund lower-carbon impact projects.

Mining companies looking for low-carbon energy solutions often realize that not all options are suited to them. Fortunately, there are alternatives for mines to achieve an optimized mix of firm power. Mines can pair new technologies and energy-storage systems with renewable energy to achieve their goals. Mine owners can explore these with technical experts. It’s important to loop in utility and government partners, too. The results may offer benefits beyond reducing carbon.

Low-carbon firm power options

Renewables are key to reducing a mine’s reliance on existing power grids. These include options we know about like solar, wind, and hydropower. Beyond that, improving energy efficiency is crucial for reducing carbon emissions. Luckily, the industry is seeing plenty of innovative solutions. Barriers to adoption are also rapidly decreasing.

One helpful approach is combined heat and power plants (CHP). CHPs generate electricity and thermal energy (heat) at the same time. Also known as cogeneration, mine operators can reuse the heat that would otherwise be lost. There are various uses for that heat. These include creating steam for electricity generation, heating buildings, or running steam chillers for cooling.

Another option involves on-site microgrids and distributed energy resources (DERs). By using these, a mine can reduce or eliminate reliance on third-party power. Microgrids offer greater flexibility and higher efficiency rates. This allows them to balance renewable power generation with traditional energy sources. Plus, mines may be able to send excess electricity back to nearby power grids. This may supply host communities with energy that is more sustainably sourced than what they have today.

Small modular reactors (SMRs) are designed with flexibility in mind. This allows them to cater to user needs. The inherent adaptability lets them scale according to specific energy demands. While the broad use of SMRs may still be a few years away, mines are already evaluating them due to their stand-alone nature. SMR designs vary in electrical output. They go from as high as 300 megawatts (MW) per module for grid-connected reactors, down to 3 MW. These compact reactors offer a reliable and carbon-free energy option for remote or industrial sites. In fact, they have done this for nuclear submarines and ships for more than 60 years. Their modularity also supports the ability to increase power capacity as the mine expands or its community’s needs grow.

Renewable energy and storage

Advancements in energy-storage technologies, such as battery energy storage systems (BESS), are revolutionizing the way mines manage their energy needs. Combining renewables with BESS is an example of DERs. DERs encompass both the software and hardware needed to generate electricity and control loads. Generally, DERs and BESS must be complemented by other energy sources. This helps to meet the mine’s energy and reliability needs.

There are many useful setups for DERs on mine sites. And technology is improving with the global focus on the energy transition. With that, costs decreasing. Let’s review some of the renewable-energy technologies that mining companies should consider:

• Solar power: Solar can work especially well at mines with large amounts of already disturbed land. Why? Because it lessens the need to disturb even more land. While a site needs favorable solar radiation, configurations have been built to work in snow-covered arctic regions. Floating solar arrays are also great options for water reservoirs on mine sites. Solar array configurations can be optimized to maximum energy production and internal rate of return. When paired with energy storage, solar can also provide power even when the sun isn’t shining.
• Wind power: By taking advantage of unused land on mine sites, wind power can augment the energy supply and reduce carbon emissions. However, a thorough evaluation of a site’s wind potential is crucial. Compliance with local and federal regulations—such as setbacks and protected areas—is essential when planning for wind power. Like solar, wind is an intermittent resource that benefits from being paired with energy storage.
• Energy storage: BESS, pumped storage, and thermal energy storage all hold potential for a mine’s microgrid. So does electromechanical flywheel energy storage. The microgrid can help level demand by reducing peak loading, storing excess renewable energy, and releasing energy when it’s needed. Longer duration energy storage is key to shifting larger amounts of renewable energy over longer periods.
• Hydropower: Many mines get energy from hydropower. Microturbine technologies can also harness energy from liquid gravity flows within a mine. This allows them to generate even more renewable energy. This approach allows for energy storage from renewable sources and strategic use during lower-rate periods. Our teams use tools to monitor and manage the significant water flows found at many mine sites.
• Geothermal: As mines go deeper, they extract materials and brines from the earth’s mantle. This exposes sources of high-temperature brines, superheated rock, and hot air. We can utilize these sources in different ways to produce energy. Many brines and ores will require cooling to meet ideal temperature and chemistry for mineral extraction. This drop in temperature can support geothermal power generation.
• Biogas: While biogas is not a new concept, it is growing as technologies improve and costs decrease. Biogas is produced when organic matter breaks down without the presence of oxygen. Then it can serve as fuel to power mining operations more sustainably. It also reduces physical waste at landfills in the process.
• Hydrogen: A rather new addition to energy toolboxes is hydrogen. Hydrogen is the most abundant element in the universe. It also releases no greenhouse gas (GHG) emissions upon combustion. It can be generated from traditional fossil fuels. This is known as blue hydrogen when carbon is captured and grey hydrogen when it is not. It can also be generated from renewable energy sources. This is as green hydrogen. Newer forms of hydrogen are emerging as well, such as pink hydrogen—which is generated from nuclear power—or turquoise hydrogen, which is produced from methane pyrolysis.

Win/win scenarios

As renewable energy and power-generation options mature, their prices are becoming more competitive with existing grids. Mining companies now have more solutions at their disposal than ever before. The concept is simple. Adopting low-carbon energy options not only reduces GHG emissions but it can also lower operating costs. It also provides supply certainty in regions where energy is scarce, unreliable, or hard to access.

As demand for critical minerals grows, new mines come online. And they are often in remote areas. Local communities in these areas may benefit from improved access to the power infrastructure that the project needs. In tandem with strong community engagement and economic reconciliation strategies, bringing lower-cost, cleaner power to host communities may help foster greater acceptance and support for mining operations.

Many current government funding programs support critical minerals. They also support the energy transition and modernizing energy infrastructure. Our team’s North American Funding Program regularly tracks funding that is available for mining. Mining operations should look into how these funding programs might enhance the financial viability of their projects.

Recommendations and actions for the future

Countries like Canada, Australia, and others are implementing carbon taxes or penalties for GHG emissions. So, mining operations should expect these future costs when evaluating energy projects.

“Green premiums”—or extra value for lower-carbon minerals—are not yet built into commodity markets. But they are being more commonly discussed. Why? To set apart metals coming from countries that prioritize responsible production.

It may be important to consider the life of the above technologies against the life of the mine. Many of these technologies have a 20-to-30-year service life as compared to the 10 or 15 years permitted life of many mines. Mines can address this disconnect by looking at the life of identified reserves. Or, at the community legacy a mine might leave after closure.

It’s complex to weigh the costs and benefits of a mine’s low-carbon energy strategy. It’s made easier when the company works with stakeholders. These include utilities, technology and service providers, governments, and host communities. So, make sure engagement occurs early and often.

Mining is shifting toward low-carbon energy solutions. With that shift are many options for sustainability and innovation. Initiatives for renewables, energy efficiency, energy storage, and new technologies can help mines reduce their carbon footprint. These efforts will enhance energy and operational resilience.

Using these low-carbon options will support a more sustainable future. They will also position mining companies as leaders in responsible resource extraction.