Description of the Action
Superconductivity is a fascinating state of matter characterised by the absence of electrical resistivity that certain materials exhibit when cooled below a certain critical, cryogenic temperature. Together with other unique properties, like the ability to carry huge currents and trap extremely large magnetic fields, superconductors pave the way for accelerating the Energy Transition.
High-temperature superconducting (HTS) materials, able to enter superconductivity above the temperature of (cheap) liquid nitrogen, make possible more compact, efficient, and even disruptive technologies that can be integrated into all the links of the electrical energy chain, from generation to transmission and distribution, use and energy storage, enabling its decarbonisation.
Despite the potential benefits and successful demonstrators of HTS technologies, they still lack mass penetration in the electrical system. Several reasons pointed out by industry include concerns related to costs and uncertainty about cryogenics’ reliability, and the idea that only highly skilled professionals will be able to operate the latter. Other causes relate to a lack of systematic knowledge about the design of HTS systems for the grid, and on how to simulate their performance using standard software packages. There is also a general unawareness about these materials, particularly on the reliability of the associated technologies.
This COST Action tackles all the above challenges, by a systemic approach that will create the path from materials to devices; foster improved modelling and advanced computation paradigms; provide methodologies and demonstrators for addressing industrial challenges and applications; and develop tools for the economic and sustainability assessment of HTS technologies.
Background
Superconductivity is a fascinating state of matter characterised by the absence of electrical resistivity that certain materials exhibit when cooled below a certain critical, cryogenic temperature. Together with other unique properties, like the ability to carry huge currents and trap extremely large magnetic fields, superconductors pave the way for accelerating the Energy Transition. In 1911 the Dutch physicist Heike Kammerlingh Onnes discovered that the resistivity of mercury samples vanished at the temperature of liquid helium (4.2 K). Yet, only with the discovery of high-temperature superconducting (HTS) materials (1986), that can enter superconductivity above the temperature of cheap and abundant liquid nitrogen (77 K), was really triggered the interest in the application of these technologies in the electrical energy chain. Up to then, commercial large-scale applications of superconductivity were restricted to magnetic resonance imaging (MRI), based on liquid helium-cooled low-temperature superconductors (LTS), nevertheless a technology with a dramatic societal impact, only made possible by these materials.
HTS materials make possible more compact, efficient, and even disruptive technologies that can be integrated into all the links of the whole electrical energy chain, from generation to transmission and distribution, use and energy storage. They enable a myriad of concepts and devices that can boost the decarbonisation of the electrical system – the Energy Transition. This directly impacts several societal sectors, besides energy industries.
The development of highly efficient devices able to deliver large amounts of power in short times embody huge savings in the energy cost and/or due to poor power quality. All-electric ships and planes become possible with more compact and novel electric motors. High-field magnets and magnetic separation open new doors in the healthcare sector or in fundamental research. HTS permanent magnets (PM) become a high-performance alternative to rare hearth PM, whose shortage or geopolitics threats can affect the development of several energy and industry sectors. Overall, HTS technologies address societal challenges unprecedentedly, leading to an energy revolution that is Hi-SCALE main driver.
Several of the successful and ongoing HTS applications throughout the energy chain include:
- Generation: some power offshore HTS wind generators have been developed, e.g. in the EcoSwing Horizon 2020 project. Fault current limiters (FCL), deployed worldwide, allow integration of distributed generators, delaying/avoiding investments of upgrading protections or reinforcing the grid.
- Transmission and distribution: HTS power cables allow high current operation, sparing transformers in substations. An MgB2 high-current DC transmission line was also demonstrated at CERN. Compact HTS transformers allow overload operation without lifetime degradation.
- Energy storage: flywheels with HTS contactless bearings store energy in a spinning mass, which can be delivered to the grid e.g. in uninterruptible power supply applications, as the 5 kWh/100 kW device from Boeing. Superconducting Magnetic Energy Storage (SMES) systems store energy in superconducting coils, delivering high powers (kW-MW) in short times (ms-s), e.g. for addressing power quality events, as the 1 MJ/0.5 MVA system in a Chinese substation25.
- Energy use: AMSC company has developed several low-speed synchronous motors for ship propulsion in the range of 5 to 36.5 MW. Industrial induction heating systems use HTS magnets to generate high DC magnetic fields, allowing to improve the efficiency of industrial aluminium heaters from around 50% (with conventional AC copper coils) to more than 80% (with HTS DC coils).
Lastly, the cryogenic system is essential for the advent of HTS grid applications. The 20-77 K temperature range (typical for power applications) can be obtained by industry-grade systems, with reduced costs and minimum maintenance. Liquid nitrogen cooling systems, able to provide a cooling power of up to 50 kW, can now be found on the market, allowing extreme operation requirements as power cables with tens of km lengths and hundreds of MVA ratings. Long maintenance intervals (above 20 000-30 000 hours) and high energy performance (around 12 electrical Watt per removed thermal Watt) of current systems are fully compatible with industrial use, with little impact on overall efficiency.
