According to a recent report by the British magazine New Scientist, with the development of the new generation of nuclear fusion energy industry, it is becoming increasingly feasible to build superconducting transmission lines without relying on any special materials. Meanwhile, its solution is relatively simple: freeze the wires. Superconductors are materials that can transmit electricity almost without resistance or loss. The earliest discovered superconductors needed to operate at extremely low temperatures or high pressures, which limited their application range and could only be used in specific fields such as magnetic resonance imaging machines. In 1986, the first type of "high-temperature superconductor" was discovered. Although this' high temperature 'is still far below the commonly understood temperature range (about -196 ℃), this breakthrough is enough to excite scientists, as it means the use of more economical and abundant liquid nitrogen as a coolant, which can be pumped into wire cores to cool superconductors. Compared with traditional copper wires, high-temperature superconducting power lines exhibit a series of remarkable advantages. Firstly, they can minimize the loss of electricity in the power grid due to heat generation. In addition, high-temperature superconducting power lines can carry larger currents in wires of the same width, significantly reducing the number of new transmission lines required. In some cases, existing copper wires can also be replaced by superconducting materials, which reduces the space required for power transmission and eliminates the hassle of laying new lines. At present, several high-temperature superconducting power lines have been put into operation worldwide, ushering in a double leap opportunity. For example, the 200 meter underground line connecting two substations in the suburbs of Chicago, USA, and the world's longest 1-kilometer line located beneath Essen, Germany. However, these lines are relatively short and only suitable for special environments with limited space. Upon investigation, the high manufacturing and cooling costs are the limiting factors. However, David Lalballestel from the National High Magnetic Field Laboratory at Florida State University in the United States stated that several significant developments may change the status quo and usher in a "historic era" for superconducting power lines. One reason is that as manufacturers improve their production methods and achieve large-scale production, the cost of superconductors themselves is decreasing. This is mainly due to the strong demand in the emerging fusion energy industry, which is seeking to use superconducting materials to build powerful magnets in fusion reactors. For example, a US fusion energy startup called Federal Fusion Systems plans to wrap a reactor with "superconducting tape". They expect to use 10000 kilometers of high-temperature superconducting tape this year. This type of superconducting tape is stacked layer by layer to form a very powerful electromagnet, which shapes and constrains irregular plasma and keeps most charged particles away from the tokamak wall. The company believes that this new method can be used to build a smaller and cheaper high-performance tokamak. Another opportunity is that the profound transformation of the global energy structure is calling for unprecedented expansion of transmission capacity. In order to transport renewable energy sources such as solar and wind energy from resource rich regions to demand centers and meet the growing demand for electricity from electric vehicles, heat pumps, and data centers, building a massive new transmission network has become an urgent task. The International Energy Agency estimates that in order to achieve climate goals, the world will need to add or replace approximately 80 million kilometers of power grids by 2040, which is equivalent to the total length of the current global power grid. The horn of energy transition has sounded, and we are standing at the threshold of integrating this change into the real system, "said Kevin Dunn of VEIR. VEIR is a startup company dedicated to building superconducting power lines. The company has developed a technology that can transmit more electricity than traditional lines without increasing the footprint, thereby achieving efficient long-distance transmission. So far, high-temperature superconducting power lines have been using a "closed-loop" system, which cools the wire core by injecting liquid nitrogen. And VEIR's method is to set up stations every about one kilometer along the power line to recover liquid nitrogen. This "open-loop" system allows liquid nitrogen to evaporate from the passive heat exchanger at the site, greatly improving cooling efficiency. Last year, VEIR laid a 30 meter long transmission line in Walburn, Massachusetts, USA, which has a transmission capacity 5-10 times that of traditional lines and does not require additional infrastructure construction. This is expected to simplify grid expansion, which is crucial for supporting renewable energy and enhancing grid resilience. However, there are still doubts about high-temperature superconducting circuits, such as how to repair them after a storm and how to train workers to handle related issues. In addition, there are other simple methods to expand transmission capacity without using high-tech superconductors, such as replacing copper wires with slightly better conductors. (New Society)