HTS cables, capable of transmitting electricity with zero resistance at higher temperatures than traditional superconductors, represent a revolution for electrical networks and many industrial applications.
Since their discovery, superconductors have promised extraordinary technological innovations, but many practical applications have proven impractical. However, science advances, and researchers at the University of Buffalo (New York State) have studied high-temperature superconducting cables that appear to be the most efficient in the world. For superconductors, which conduct electricity with zero resistance, the previous designation of “high temperature” is crucial. Traditional superconductors only operate at “super-cold” temperatures, below 30 Kelvin (-243.15°C), while high-temperature superconductors can function at temperatures above 77 Kelvin (-196°C).
Although the difference might seem minor given the extreme cold, this type of cable can be cooled to superconducting conditions using relatively affordable and manageable cryogenic systems, utilizing liquid nitrogen as a refrigerant.
The importance of the Buffalo researchers’ discovery opens the door to a range of further studies on superconducting cables, starting from a well-known physical reality: normal electrical conductors resist the flow of electrons, leading to energy waste and heat generation, whereas superconductors conduct electricity without dissipating energy, making ultra-efficient electrical networks possible. Additionally, the enormous current flows they can handle mean that superconductors can also serve as powerful electromagnets, useful for applications such as magnetic levitation trains and improved medical diagnostic systems. However, large-scale applications are only feasible if cost-effective manufacturing processes for high-temperature superconducting wires are developed, which is the ultimate goal of the research we introduced in this article.
To provide further technical detail, the new cables are based on rare-earth barium copper oxide (ReBCO) and could transport approximately 9.3 million amps per square centimeter, five times more than the high-temperature superconducting cables currently available on the market.
HTS Cables
Power transmission using high-temperature superconductors is one of the most revolutionary accredited technologies in the energy sector. If a method were found to achieve superconductivity at room temperature, it would revolutionize the way energy is produced, stored, and transported, significantly contributing to reducing greenhouse gas emissions responsible for global warming. Currently, about 10% of all generated electricity is lost in long-distance high-voltage cables. A room-temperature superconductor could also store energy in superconducting circuits, enabling the retention of low-cost renewable energy until needed.
In applications such as motors and generators, HTS cables would significantly improve the weight-to-power ratio, increasing, for example, the efficiency of electric vehicles.
The current state-of-the-art focuses on High-Temperature Superconducting (HTS) cables, which utilize superconducting materials in a liquid nitrogen environment at approximately -200 degrees Celsius, near absolute zero. In this case, the energy transfer medium exhibits near-zero resistance, making energy transfer losses virtually nonexistent. Special copper-based oxides possess superconducting properties, and this discovery has been a major breakthrough in the realization and practical application of HTS cables.
In basic structure, simplifying beyond manufacturer-specific variations, an HTS cable consists of four main components: wire core, cryogenic container, finishing, and cooling system. The cable core is fundamental and includes key components such as the conductive layer, insulation layer, and shielding layer. Within the outer cable jacket, there is a double-layer stainless steel adiabatic Dewar tube, with liquid nitrogen flowing through it and immersing the superconducting wire core. A cryogenic cooling device supports the system by regulating the liquid nitrogen cycle and maintaining the required cooling levels.
A growing market
The growing demand for efficient and reliable power transmission systems is driving the expansion of the HTS cable market in the coming years. Among the major trends, the most significant include the research and development of advanced materials capable of handling higher temperatures and currents. Additionally, the increasing demand for renewable energy requires high-temperature superconducting cables to efficiently transmit electricity over long distances.
Furthermore, the medical and transportation sectors are contributing to HTS cable demand, particularly for MRI equipment and maglev (magnetic levitation) trains. The HTS sector is also witnessing the entry of new players and startups that are revolutionizing the market by offering innovative solutions and challenging traditional industry leaders.
Overall, the HTS cable market is expected to experience significant growth, with particular focus on improving efficiency, reducing energy losses, and expanding applications across various industries.
As for product segmentation, the market is divided into YBCO Cables, Bi-2212 Cables, and Bi-2223 Cables. YBCO cables, primarily composed of yttrium-barium-copper oxide as the superconducting material, dominate the market due to their superior performance characteristics, including high critical current density and a transition temperature of approximately -180°C.
Regarding usage, HTS cables are predominantly applied in smart grids to enhance power transmission efficiency and minimize energy losses. In industrial applications, they are used in motors, generators, and transformers to boost performance. Market research identifies Nexans (France) as the leader in the HTS sector, offering a diverse range of products for various industries. Notably, its superconducting technology is displayed at the Science Museum in London. Another key player is Furukawa Electric (Japan), a pioneer in superconducting technology, known for groundbreaking innovations
