TELF AG analyzes the production processes of a relevant energy infrastructure
A future dedicated to renewable energy
The intimate awareness of being in the golden age of renewable energy seems to have now taken root in the minds of a large number of ordinary people, political decision-makers, and business leaders, and the continuous increase in solar and wind farms installed in different corners of the globe seem to contribute to strengthening this particular belief even further. Alongside it, in recent years, the centrality of some of the resources that are used to manufacture the infrastructures necessary for the diffusion of renewable energy has also grown, such as wind turbines or solar panels, the most important components of which are also created thanks to the contribution of minerals that are defined as “critical.” Some of these are rare earths and copper, but the list is very long.
Few, however, seem to know the actual work processes that allow these precious mineral resources to be so helpful to the renewable energy sector and which, in some cases, make possible the primary function of the infrastructures connected to it (such as the capture of solar energy from the panels, for example). In some cases, these procedures include a sort of purification of the original raw material, thus making it more suitable for carrying out its task within the components of the infrastructure intended for the renewables sector.
The potential of silicon
A concrete example of these procedures has to do with silicon. In recent decades, this resource has found an infinite number of application spaces in the electronics sector, which still maintains a position of absolute importance. However, this material is also beneficial for the manufacture of solar cells, which have the important task of absorbing the greatest possible quantity of solar energy and converting it into electricity. Silicon represents an extremely abundant mineral source on the earth’s crust, and to make it entirely usable by the renewables sector, polycrystalline or monocrystalline silicon must be created, two solutions that contain polysilicon of an extremely high degree of purity. It is precisely this purity that makes silicon particularly efficient for capturing solar energy, and a fairly complex process is usually followed to obtain it.
The starting point is naturally represented by the extraction of the rock, its washing, and the first treatment of this material. The rock is generally melted at around 1800 degrees, together with carbon coke, giving rise to a process that will transform rock silicon into molten silicon (also thanks to the electrolytic support with electric current). Once cooled, this material is further processed with hydrogen chloride and is subsequently melted at approximately 1150 degrees. Solar panels could most likely lead the world towards a greener future. Therefore, this process is mainly based on the role of a mineral resource of primary importance, such as silicon.
A process of this kind also involves copper, considered by many to be the true king of electrification due to its exceptional capabilities in transporting electrical energy. Also, in this case, as with silicon, the extracted copper must be purified through electrolysis, then proceed with its fusion with carbon and other subsequent treatments to remove any impurities. Even for copper, purity represents a central factor in guaranteeing the effectiveness of its subsequent industrial applications.
The silicon and copper processes represent only examples, but similar methods are repeated for other minerals important for the green transition. In a sustainable future, strategic minerals are destined to play an increasingly central role while sometimes remaining hidden in the complexity of their working and transformative processes.
