The transition to e-mobility faces scepticism from motorists, who are concerned about the range of electric vehicles and the lack of adequate network of fast charging points. Sanef, a subsidiary of Spain's Abertis (Mundys Group), has responded to this demand by installing more than 500 ultra-fast recharging points in the 72 service areas it operates in France, which implies a recharging possibility every 50 kilometres of motorway.
The multiplication of filling stations creates an issue of refuelling and consumption peaks. Seemingly irreconcilable technologies, such as superconductivity, could solve the problem, bringing into everyday life solutions that for decades have found application in the world of research and medicine, and today, thanks to scale-up of materials and innovative cooling techniques with industrial costs and reliability, reach the world of energy distribution and storage.
Thanks to the discovery of new superconducting materials such as MgB₂, or magnesium diboride, which is much more sustainable than others requiring rare earths, it is possible to make cables capable of transporting huge amounts of energy at a voltage level that can be used to generate energy from renewables or to recharge the batteries of the latest generation of electric cars.
And all this takes place without any energy dissipation and related voltage drop in the cable, over distances that can be multi-kilometres with better performance than copper. ‘Traditional’ superconductors operate at cryogenic temperatures, such as those reached by hydrogen in liquid form (-250°C). While these temperatures may be frightening, it should be remembered that everyday tens of thousands of MRI machines around the world are cooled to a temperature of -269°C and contain many tens of kilometres of superconducting wire each.
The perfect ‘combo’ for the transmission of energy along our motorways can be imagined through a single infrastructure, basically a pipeline with the diameter of about a palm, capable of simultaneously transporting both electricity, ready for the fast-charging columns, and hydrogen for the filling up of trucks, which will most likely prefer it to batteries.
In this way, it is possible to centralise energy production, storage and management in a single location, suitably positioned to handle each motorway branch that may exceed 100 km in length, maximising the flexibility and sustainability of the solution, being able to direct flows of electricity and hydrogen, also selectively, to recharging areas that may be momentarily more stressed, for example following a road block, or an unexpected, or in any case above-average, flow of vehicles. Other possible dedicated applications can be imagined for airports or intermodal logistics centres. The cooling necessary to make the cable perform and be superconductive is possible with reliable cryogenic technologies and with reduced costs that are largely covered by the energy savings guaranteed by the ‘zero’ dispersion inherent in superconductivity.
This solution may seem a little too futuristic, but in fact the European Union has recently funded a project within the framework of Horizon Europe with a total amount of around Euro 15 million and one of its aims is precisely a long-term test of at least six months of a MgB₂ superconductor cable, cooled with liquid hydrogen flow and enabling the transport of a power of around 1 GW at a voltage level unimaginable to date with conventional technologies, of only 25 kV.
And this project comes after important precedents, among which the work by Cern stands out, which with the MgB₂ realised superconducting lines with a weight and size within human reach, but capable of carrying current intensities of 120,000 amperes through a flexible cable. Compared to the current intensities we are talking about today with the latest electric cars, of approximately 500 amperes, such a cable would be able to directly power the simultaneous fast charging of no less than 200 of them.
And as far as costs are concerned, to date, an MgB₂ wire that can carry 500 times more electrical current than copper with the same cross-sectional area can do so at a fraction of the cost of an equivalent copper solution.