It is no secret that Europe is trying to wean itself off Russian gas after the invasion of Ukraine. European citizens find themselves in the repulsive position of propping up the Russian regime through the purchasing of Russian gas to power our electrical grids. There is also a massive effort within the EU to divest from carbon producing means of energy production. The task of divesting from fossil fuels and untangling European economies from Russian gas is immense but what if Europe could pool its energy resources together to create one, large, pan-European grid? If this could happen wind farms off the west coast of Ireland could power factories in Germany or solar panels in Portugal could power homes in Italy. This way, when the wind doesn’t blow or the sun doesn’t shine in one region of the continent, energy can be produced in and distributed from another. The problem with this idea is that it costs to transport electricity. This cost is attributed to transmission losses due to heat as well as financial costs due to large transmission and collector stations needed to transmit power. This is where superconductivity comes in.
Superconductivity is a phenomenon in physics where certain materials display zero electrical resistance when cooled to temperatures of around 80 Kelvin (-1930C). Superconductivity is a quantum effect best described by Cooper pairs. In a normal conductor, electrons flow freely throughout the lattice of atoms and are repelled by one another. Events such as scattering, the collision of an electron with an atom, diminish the flow of electrons and cause resistance. However, in a Cooper Pair, electrons are slightly attracted to each other. This attraction is due to electrons interacting with phonons which are waves of vibration in the lattice. When these electrons are paired up, they have a lower energy. This creates an energy gap between the energy of the electrons and the energy needed for events such as scattering, meaning scattering will not occur and resistance falls to zero. Superconductivity only works at low temperatures as the Cooper bond in an electron pair is very weak and thermal energy, the energy due to temperature, can break the bond in these Cooper pairs. The temperature below which a material exhibits superconductivity is called the critical temperature.
So, superconductivity allows the flow of electricity with zero resistance, and therefore zero power loss, if the conductor is below a certain temperature. An important temperature in superconductivity physics is 77K, the temperature Nitrogen boils at. This is because if a superconductor with a critical temperature above 77K is used, liquid Nitrogen can be used to cool it. Liquid Nitrogen is readily available and relatively easy to produce, making it the perfect cooling agent.
Superconductivity is going to play a massive part in the future of energy transportation in Europe and indeed in the world. It is an area where physicists can contribute to one of the biggest questions facing our generation with regards to energy security. “How do we keep the lights on?”