Conceptual Design of a SuperConducting Energy Pipeline for LH₂ and Power Transmission Over Long Distances

The design of a single-pole MgB2 superconducting hydrogen-cooled cable for DC current transmission at low voltage (10 kV) is presented here. The cable consists of a former made of MgB2 superconducting wires, a dielectric layer and an annular region that allows for the passage of hydrogen at inlet pressures above the critical one. The cable is contained within a corrugated cryostat, insulated from the external environment. The use of MgB2 as a superconducting material allows for the operation of the cable in the range 15-27 K, which reduces the cooling requirements and increases the efficiency of the system. The hydrogen-cooled annular region, acting as a pipeline for the cryogen transport, allows at the same time the efficient cooling of the cable, while the corrugated cryostat provides additional insulation and structural support, together with a relief volume in the case of an accident. The results of this study, mainly performed with a simplified model, benchmarked against the OPENSC2 software, show that the cable is able to support DC current transmission at 10 kV, with maximum cable lengths of several tens of km for inner diameters of the cryostat >120 mm, supporting a H-2 mass flow rate >1 kg/s. Overall, this study demonstrates the feasibility of combining the DC current transmission at low-medium voltage by MgB2 to the transport of liquid hydrogen, providing at the same time instantaneous storage of chemical power.