Powering our mines: Transitioning from hydrocarbons to renewables

Measuring emissions at mine sites

Many mining companies have started to make stronger ESG commitments. To do this, they often require energy and pollution experts—that’s where we come in. Our clients understand that producing their own energy in-house will give them more control of overall emissions. But how?

First, we need to understand the levels of greenhouse gas (GHG) emissions that they are trying to curtail. The US Environmental Protection Agency (EPA) utilizes three components, or scopes, to measure an organization’s overall carbon footprint:

• Scope 1: Direct emissions that come from an organization itself and anything it owns or controls, such as facilities or vehicles.
• Scope 2: Indirect emissions that result from a company’s energy needs, such as those associated with the purchase of electricity, steam, heat, or cooling.
• Scope 3: Indirect emissions that result from a company’s upstream and downstream processes, such as the transportation, processing, and use of its end products.

Current emphasis has been placed on reducing Scope 1 and Scope 2 emissions. Many mining companies are targeting energy efficiency improvements to reduce Scope 1 emissions and developing renewable generation sources to reduce Scope 2 emissions. As power companies and utilities (who would otherwise provide power for mines) continue to try to reduce their GHG emissions, they are charging more for energy because of the need to upgrade existing infrastructure. That cost increase is usually passed down the line to mines or any other end user.

Furthermore, many of the power industry’s sustainability initiatives focus on reducing their Scope 1 emissions, which may not necessarily align with a mining company’s Scope 2 concerns. For this reason, some larger mining companies are beginning to realize that, by generating their own power in-house, it is much easier to control their Scope 1 and Scope 2 emissions. And it can be more cost-effective in the long run. 

Producing energy on mine sites

As outlined above, mining companies can recognize the benefits from producing their own power on site. From an increase in efficiency to a decrease in both future operating costs and GHG emissions, there are plenty of reasons for mine operators to also become energy providers. So, what steps can they take now to produce their own power in the future?

A combined heat and power plant (CHP) is a great self-generation solution for mine sites. Also known as cogeneration, a CHP plant generates electricity and thermal energy (heat) at the same time. This is a more sustainable solution for mine operators because the heat, which would otherwise be lost in the process, can be reused for other purposes. These include creating steam to generate electricity, heat buildings, or run steam chillers for cooling. Not only does a CHP generate a cleaner form of electricity, but it gives mine operators more control of their Scope 1 and Scope 2 emissions.

Another effective way for mines to gain more control of their GHG emissions is to create their own microgrid on site. By establishing its own microgrid and distributed energy resources (DER), a mine site is less reliant—or not reliant—on power providers. This affords them more flexibility and higher efficiency rates.

DER can bring together many forms of power generation and use them towards a common goal. For example, energy produced at the CHP plant can be supplemented with renewable energy sources like wind, solar, or hydropower. This gives operators even more leverage when they are working to reduce their carbon footprint.

The best part? With DER and microgrids, mines can send any excess electricity back to nearby power grids to serve communities in need—sometimes with energy that’s more sustainably sourced than the status quo. 

Integrating renewable energy into operations

As we touched on earlier, DER can use electricity that is generated from multiple sources. This is great for mine operators because they can supplement energy produced at the mine site with renewable energy technologies, which gives them even more control over both Scope 1 and Scope 2 emissions. For some practical examples, see the Stantec Webinar on Net Zero Mining hosted by CIM Magazine.

There are many different forms of renewable energy that can be useful on mine sites. And with the global focus on the energy transition, technology is improving, and cost is coming down. Let’s review some of the renewable energy technology that mine companies should be considering:

• Solar power: Solar energy, or energy generated by the sun, is an effective way of integrating renewable energy at mine sites. This is particularly true at mines with a large amount of unused land, and which have favorable solar radiation. This land can be used for cells of solar panels to help supplement the energy supply when the sun is shining.
• Wind power: Electricity generated from wind turbines is another great source of renewable energy at mines. Wind power also takes advantage of land that isn’t being used on mine sites to augment the energy supply when the wind is blowing and reduce the operator’s carbon emissions.
• Hydropower: Several mining clients already generate a substantial amount of their energy from hydropower. Further developments in microturbine technologies also provide opportunities to recover energy from gravity flow liquid systems within a mine to generate additional renewable energy.
• Biogas: While biogas is not a new concept, the adoption of it has grown significantly as improvements to technology and reductions in cost have occurred over time. Biogas is produced when organic matter breaks down without the presence of oxygen. The resulting biogas can then be used as fuel to power operations at a mine in more sustainable way—and it reduces the amount of physical waste at landfills in the process!
• Hydrogen: A rather new addition to our energy infrastructure is hydrogen. Hydrogen is the most abundant element in the universe, and it releases no GHG emissions upon combustion. It can be created through three methods: Grey, blue, and green.
• Energy storage: Battery energy storage systems (BESS), pumped storage, and electro-mechanical flywheel energy storage all have potential uses of being incorporated into a mine’s microgrid. These technologies help to level demand by reducing peak loading and storing excess renewable energy generated.  

More sustainable mines, more sustainable future

We know that mine sites require a significant amount of energy to operate. But we also know that mining is an essential component in achieving a more sustainable future. Why? Because the metals we need to reduce our reliance on fossil fuels and advance towards renewable energy are still in the ground. Metals like nickel and lithium are needed to produce technologies like solar cells and batteries, while copper and aluminum are critical for transmission and distribution.

We hope that mine operators can take away some key lessons learned here. Understanding the scopes of emissions and how operators may potentially reduce their carbon footprint will be essential for mining companies to reach commitments and ESG standards heading forward. If they understand what options are available, they can take action, plan for self-generation solutions, and incorporate renewables into their operations.