In a groundbreaking achievement, Chinese engineers have successfully activated the world’s first 35 kV superconducting power cable in Shanghai, setting a new milestone in the field of power transmission technology. The cable, an impressive 3/4-mile (1.2 km) in length, has been hailed as the world’s longest kilometer-level superconducting cable, distinguishing itself by operating within an urban core and being entirely installed in ducts.
Superconducting power cables utilize superconductivity to transmit electricity with minimal losses. The core principle involves leveraging superconducting materials to reduce the resistance of power transmission nearly to zero, achieved by maintaining low temperatures using liquid nitrogen. This innovation allows a single superconducting cable to carry the same power load as four to six conventional cables at the same voltage level, resulting in a remarkable 70 percent reduction in underground pipe space requirements.
The cable’s voltage of 35 kV places it at the higher end of the medium voltage range, a common choice for urban and semi-urban applications. Shanghai, like many large cities, primarily employs superconducting cables for its distribution networks due to their suitability for the density and power demands of urban areas.
Noteworthy is the cable’s exceptional length and installation within ducts, a unique feature that sets it apart from similar technologies. This achievement is the outcome of two decades of relentless efforts by engineers at the Shanghai Electric Cable Research Institute (SECRI) under Shenergy Group, a company with a 60-year legacy in the electric cable industry.
Huang Chongqi, a member of the Chinese Academy of Engineering and a superconducting cable expert, highlighted the potential impact of widespread superconducting cable use, particularly in addressing challenges related to high electricity density and limited space in super-large cities like Shanghai. The cable project is a testament to China’s commitment to independent innovation, as the SECRI team significantly reduced the cost of superconducting raw materials, previously monopolized by foreign countries.
The successful deployment of this superconducting cable comes at a time when China has already constructed the world’s largest power system, boasting a transmission line length above 35 kV spanning 1.4 million miles (2.26 million kilometers). The Shanghai project is not merely a remarkable accomplishment in its own right but is seen as a catalyst for the development of even longer cables, with experts envisioning 3-mile (5 km) and 6-mile (10 km) iterations on the horizon. Zong Xihua, deputy chief engineer of SECRI, proudly stated, “Now, we have made an early start in superconducting power transmission technology and taken the lead globally thanks to two decades of research and development efforts.”