The apparent need for a transition of the world’s energy consumption to renewable sources lead to a demand in technological innovation along the use chain of electric energy. Sustainable generation, transportation, distribution and storage solutions of electric energy from an increasing number of intermittent sources are required. An increase of the energy-efficiency of applications, including energy-intensive industries, the mobility and housing sector are required to reduce the overall energy consumption. Superconductors, in particular high temperature superconductors (HTS), offer various technical solutions to these needs in generation, transportation, and storage of electric energy.
In this presentation, an overview of two projects and recent results involving so-called HTS CroCo strands – soldered stacks of REBCO tapes of two different widths - are given and an outlook to recently a started activity is presented.
On the longer perspective, electricity generation from nuclear fusion of hydrogen isotopes may become a source of CO2-free electric energy. HTS are considered in future fusion machines to enlarge the design space (e.g. regarding operational temperature and magnetic field) of presently used low-temperature superconductors (LTS). For example, HTS are the enabling materials of the magnet system of compact fusion machines.
One of the challenges in the application of HTS materials in large fusion magnets is the substantially smaller quench propagation velocity in HTS compared to LTS. In an international project, quench properties of fusion-relevant HTS cable-in-conduit-conductors are investigated. A sub-scale fusion conductor based on a triplet of HTS CroCo strands, including additional copper and a stainless steel jacket, is designed and investigated.
Recent results on design and qualification steps towards the realization of the sample will be presented, including the results of a mock-up sample at 4.2 K, 12 T.
Some electrolysis plants, in particular for aluminum electrolysis, operate at direct currents beyond 100 kA. A substantial energy saving can be achieved if normal-conducting busbars are replaced by superconducting solutions. In previous work (e.g. presented at ISS 2019), results on a 35 kA (at 77 K) high-current busbar demonstrator made from HTS CroCo strands was presented.
Within the research project DEMO200, a 200 kA busbar made from ten 20 kA modules towards an application in an aluminum smelter is developed. Several options for the implementation of the 20 kA modules are investigated, including one option based on an arrangement of HTS CroCo strands. Results on the design, pre-tests towards the compensation of the thermal expansion, and HTS CroCo strand manufacturing, will be presented.
Hydrogen (H2) is one attractive renewable energy carrier and key element of many future energy scenarios, in particular for mobility applications. The energy density, purity and low-pressure storage and transportability are relevant properties of liquid hydrogen (LH2), which make the liquid state attractive as fuel in large-scale mobility applications. If the liquid state is targeted e.g. for long-range transportation option and as fuel in mobility applications, the combination of the cryogenic temperature level with superconductivity is of particular interest. The pipeline transport of liquid hydrogen combined with electric energy transport through a superconducting cable will be discussed as outlook towards future research activities.
Acknowledgment:
This work has partially been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2021 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
The work presented in this contribution was in parts funded by the German Federal Ministry of Economics and Energy under Grant No. 03ET1670.
The work presented in this contribution was in parts funded by the German Federal Ministry of Education and Research under Grant No. 03HY204A.