EN 
PT_BR 
Mining is an industry with high energy demands. Digging, crushing and processing minerals requires a lot of energy and mines generally operate 24 hours a day, seven days a week. Like other industries, mining companies are looking for solutions to reduce their emissions. Both for the good of the planet and in response to increasing pressure from its customers to adopt a more ecological approach. More and more manufacturers that use minerals in their production chain are looking for ways to make their processes more sustainable. Although raw materials such as rare metals are essential for the manufacture of products, such as electronics and electric vehicles, there is a great demand for suppliers of these inputs whose operations have lower carbon emission intensity. Brazil has rich metal reserves, producing and exporting around 80 mineral commodities, making the country the sixth largest mining industry in the world. However, Brazilian mines are often located in remote regions and outside the energy grid, which makes their decarbonization options limited. Without access to an energy grid, mines end up having to resort to polluting generators and oil-powered cars to obtain the necessary energy. With the falling cost of renewable energy, however, decarbonization across the mining industry is becoming economically viable. Given this, industry operators have been analyzing how microgrids can allow them access to renewable energy in operations outside the energy grid.
Solar energy microgrids
Solar photovoltaic energy is a proven technology that provides clean, cheap energy to help meet energy demands around the world. In this modality, solar energy assets are generally connected to the energy grid, which allows any energy that is not consumed where it is generated to be fed back into the grid. The main disadvantage of using solar energy alone is that it is not capable of generating energy 24 hours a day. However, solar microgrids are hybrid solar energy generation and storage systems that provide access to electricity even when the sun is not shining. They act as local, self-sufficient energy grids that can serve a neighborhood, campus or company. Microgrids can operate alongside an existing energy grid, or completely independent of it. Nowadays, using batteries is the simplest way to store energy. However, hydrogen is also becoming a viable solution, as the cost of specialized equipment for this type of storage decreases.
Main benefits
Solar microgrids allow companies to decarbonize their operations outside the energy grid, abandoning energy generation from fossil fuels. Power is generated on site, which eliminates the need to transport diesel. A 1 MW solar plant typically produces 2,000 MWh annually and can replace around half a million liters of diesel. Due to the low cost of equipment and the longevity of assets – which typically last up to 30 years – solar energy has become one of the most economical energy sources. It is also relatively low maintenance compared to diesel generators, as well as offering greater supply reliability and better commercial resilience. Battery costs are also on a downward trajectory, with projections predicting a decline of 50% from 2017 to 2030. Connecting a microgrid to the main energy grid can also improve grid reliability by maintaining an optimal balance between production and energy consumption. Battery storage acts as a “wiring reserve” to compensate for generation failures. Having a more reliable energy infrastructure brings economic value to society, increasing productivity and improving people's quality of life. When a microgrid is connected to the energy grid, its operators can still provide support to grid operators. This is done by providing ancillary services to help them maintain a stable power frequency through a grid balancing system. In other words, in addition to a source of electricity, the microgrid can also become a source of income. Energy consumption is responsible for up to 30% of the operating costs of a typical mining activity, therefore, any cost reduction can have a major impact on the total value of the operation. By committing to long-term renewable energy purchase agreements (PPAs), typically ten to 15 years in length, mining companies have access to cheaper energy. While the price of diesel is often volatile and unpredictable, PPAs provide buyers with predictable prices for their energy over the long term. Another benefit of PPAs is that they allow companies to access low-carbon energy from photovoltaic solar parks without having to invest capital in their own power plants. Companies commit to purchasing a certain amount of electricity per year, over a certain period, at an agreed rate. Even with hybrid solar systems and battery storage, users of a microgrid can often benefit from having their own microgrid without having to shell out capital. Some microgrid developers offer “battery storage as a service” business models, allowing customers to benefit from energy storage by paying for batteries through the shared economy. Independent grid operation is especially beneficial in certain regions of Brazil, where the reliability of the energy grid leaves much to be desired. In this case, microgrid users benefit from security of supply and reduced power outages.
Electrify to decarbonize
Mining companies in Africa and South America are already showing what is possible through the adoption of renewable energy. The Zaldívar copper mine in Chile will be the first mine in Latin America to operate with 100% renewable energy. As a result of a ten-year agreement to purchase renewable energy with Chilean utility Colbun, the mine will reduce its emissions by 350,000 tonnes per year. The Vametco mine in the northwest region of South Africa recently announced that it will use vanadium redox flow batteries (VRFB) to store energy from a 3.5 MW solar photovoltaic plant. The microgrid will provide almost 10% of the mine's electrical needs. VFRB technology can offer almost unlimited power capacity using electrolyte storage tanks. The electrification of mining equipment, such as trucks and excavators, is at an early stage. Currently, only 0.5% of mining equipment is fully electric. However, the cost of ownership of battery electric vehicles compares favorably to internal combustion engine vehicles. Hydrogen-powered vehicles are another zero-emission option for decarbonizing a mining operation, especially for large installations that would otherwise require huge (and heavy) batteries to provide enough power. Microgrid solar hybrid power systems offer mining companies a commercially viable path to increase their use of renewable energy and begin their decarbonization journey. As microgrids provide more cost-effective and predictable electricity prices, as well as grid autonomy and greater supply resilience, their adoption is becoming an increasingly important part of the decarbonization strategy for mining companies.
