Copper thefts are an increasingly persistent scourge. That could change. With this revolutionary discovery, researchers have succeeded in finding a replacement for copper: carbon.
Copper substitute urgently needed
Copper is a very good electrical conductor. Of all metals, only the scarcer silver conducts electricity even better. No wonder copper is widely used for electronics and power cables. Especially the strong demand from China now means that a kilo of copper can easily cost more than six euros and that no copper-containing object is safe from the thieves' guild.
Researchers have now succeeded for the first time in finding a replacement for copper.  A material that conducts electricity better than this increasingly scarce metal. The material in question is carbon, which is very common on Earth in the form of coal, carbon dioxide and carbonates. It will be a current conductor in the shape of an old acquaintance: carbon nanotubes, which look a lot like a rolled up piece of graphene. Carbon nanotubes also hold another record: the material with the highest tensile strength in the world.
Years of laborious research provides a replacement
After years of laborious work, researchers have reached the point where the current density of carbon nanotubes is as great as that of copper. That is to say: per unit volume. The material even scores six times better per kilo because it is much lighter. Individual tubes even conduct electricity ten times better than copper, but until now it was not technically possible to make a thick power cable from carbon nanotubes. The experiments were carried out with double-walled tubes, which are easier to make and process. The researchers now want to develop a power cable that conducts electricity much better than copper. To do this, they have to braid single-walled carbon nanotubes into a power cable. A tough challenge.
In addition to an end to copper shortage, the new, light copper substitutes also save a lot of weight. Good news for aircraft and spaceship builders. Carbon is very resistant to corrosion, so the carbon power cables can also be used in chemically very hostile environments. If the researchers can live up to the promise of a much better conductive alternative to copper, which they are going to try, it means that the seven percent of energy that is now lost in the high-voltage grid as transport losses will be halved or better. This applies even more so to the power cables in the house. So there is a chance that these cables will pop up all over the house and that the copper will be melted down again into beautiful statues or coins. What else can you do with it?
Slow advance of copper substitutes
The advance of carbon nanotubes as conductors turned out to run less smoothly in practice than first thought. It is still very expensive to produce carbon nanotubes in large quantities, although prices are falling. At the beginning of 2021, these will be around 200 euros per kilogram. This is still many times more than copper. However, the density of copper is much higher than that of carbon nanotubes. And not all problems have been solved yet. Researchers are still struggling to get the tubes connected together. As long as that doesn't work, a lot of internal resistance remains in the cables. The first applications will probably be in aerospace and aircraft. Weight saving is very important here.
In 2019 the “technical readiness level” was almost 3. This means that the principle has been shown to work, but there is no lab-validated prototype yet.  So don't short-sell copper mines for the time being. But in the somewhat longer term, copper will probably go the way of the Bakelite. Certainly, now that a major manufacturer, Yazaki, already incorporates carbon nanofibres into aluminum cables to allow them to conduct current as well as copper .
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