Inside China's Pioneering Quantum-Powered Demonstration Substation Discover how China's Houdian demonstration substation in Hefei integrates cutting-edge quantum technologies to enhance power grid safety, efficiency, and cybersecurity. Par Xu Jing, People's Daily Quantum technology is beginning to transform the way China's power grids operate. At the 220-kilovolt Houdian Quantum Application Demonstration Substation in Hefei, east China's Anhui province, a suite of advanced quantum technologies is now in use. These include diamond-based quantum sensing materials to monitor current fluctuations, quantum-dot gas sensors to detect potential cable fire hazards and partial discharge faults inside switchgear, and other innovations that strengthen the intelligence, safety, and efficiency of grid operations. Commissioned in November 2024, the facility is China's first demonstration substation dedicated to the systematic application of quantum technologies. It has deployed 85 independently developed quantum devices across 18 categories, covering quantum sensing, quantum communication, and quantum computing. The project represents a pioneering effort to integrate quantum technologies into power grid engineering, offering a new technological solution to the challenges faced by conventional power grids while supporting the development of a new-type power system. The substation also represents a new generation of fully unattended intelligent substations. "We have replaced many manual inspection tasks with high-precision quantum sensing equipment," said Tian Teng, a young engineer at the digitalization institute of the electric power research institute under State Grid Anhui Electric Power Co., Ltd. "The new system can identify and diagnose equipment defects much faster, reducing both inspection costs and operating expenses." Inside the high-voltage switchgear hall, rows of power equipment operated steadily. Standing beside an out-of-service switchgear cabinet, Tian pointed to a small device mounted on its side. "This is a quantum-dot multi-parameter sensor," he explained. "It continuously monitors the cabinet's internal environment and detects signals associated with partial electrical discharge, enabling us to assess the