Thermo-hydraulic and economic aspects of long-length high-power MgB2 superconducting cables

The rising share of renewable energy in the European grid creates a demand for long-length, high-power transmission lines. Superconducting cables represent an attractive option for such connections, offering considerable savings in energy and space for installation. Due to its low cost, the MgB2 superconductor might be an interesting choice, but it requires to be operated at very low temperature. In this paper, a simple thermo-hydraulic model is developed, which allows for a fast assessment of the main dimensions of a four-wall cryogenic envelope around a high-power MgB2 cable as well as the achievable distance between two cooling stations. This model is then expanded to provide the budgetary cost of such a link including the components of the cryostat and the necessary cooling stations. A significant cost reduction as compared to a resistive link can be found for a transmitted power of 6.4 GW. Different optimizations are investigated, which result in further savings.

Automated summary

The increasing share of renewable energy in the European grid requires long-length, high-power transmission lines. Superconducting cables, particularly using MgB2 superconductors, offer significant energy and space savings but require operation at very low temperatures. A simple thermo-hydraulic model is developed to assess the dimensions of a cryogenic envelope around a high-power MgB2 cable, with findings showing cost reductions compared to traditional resistive links at a transmitted power of 6.4 GW. Further cost savings are possible through optimization strategies.