China Telecom has announced the independent research and development of its own energy storage system. The company is also making forward-looking investments in 800V high-voltage direct current and immersion liquid cooling technologies. These developments were highlighted in the company's 2025 Sustainable Development (ESG) Report, released on March 26, 2026. Among its innovative projects is the world's first offshore wind-powered submarine data center. The proportion of green electricity used in its data centers increased by 56% year-on-year.
In the area of green energy usage, China Telecom is continuously advancing the transformation of its energy consumption structure. The company actively participates in the electricity market and has formulated a phased, scenario-based green energy plan tailored to regional resource characteristics and provincial business needs. For two consecutive years, the company has been ranked first in its industry on the "China Top 100 Green Electricity Consumption Enterprises" list.
During 2025, the company promoted the coordinated development of computing power and electric power. It actively explored new power supply models, such as integrated "source-grid-load-storage" systems, direct green power supply, and local consumption. This effort led to the creation of several benchmark projects, including the world's first offshore wind-powered submarine data center in Shanghai and the nation's first high-altitude cave-based intelligent computing center with computing pods in Sichuan. These projects set new directions for green, low-carbon development in the industry. Through green power and green certificate transactions in 2025, the company procured a total of 4.2 billion kilowatt-hours of green electricity.
China Telecom is building a new AI Data Center foundation for the intelligent era. Guided by the principle of "High IT Output, High Density, Flexible Expansion, and Flexible Construction," the company is using architectural innovation to drive the green and intelligent transformation of its data centers. This approach meets the extreme demands of AI model training for high bandwidth and low latency while enabling modular, prefabricated rapid deployment. It also significantly reduces energy consumption and carbon footprint throughout the lifecycle.
The company is strengthening its green, self-developed technologies to enhance energy efficiency. It has intensified efforts in green technology research, independently developing over ten energy-saving products, including the "Yi Anneng" smart energy storage system and the "Yi Jibing" precision cooling energy-saving pod. It is also making前瞻布局 in key technologies like 800V high-voltage DC, decoupled liquid cooling, and vertical immersion cooling. Deeply involved in establishing green standards, China Telecom has led the release of 24 international and domestic standards, providing solid support for optimizing the energy efficiency of information infrastructure.
In a specific case, China Telecom's Sichuan branch, in partnership with the Yalong River Hydropower Development Company, part of the SDIC Group, built the country's first high-altitude cave-based intelligent computing center with computing pods in Lianghekou, Ganzi Prefecture, Sichuan. This project serves as a pilot demonstration for Ganzi Prefecture's "1+4+N" integrated computing-power development framework. It explores new models for the synergistic development of computing and power, promoting the coordinated growth of the digital economy and green energy. Leveraging the safety and constant temperature advantages of the cave, the facility has an earthquake resistance rating of 8 degrees and a PUE of less than 1.2. It uses an integrated hydro-wind-solar power supply, operates on 100% green energy, and converts green energy locally into green computing power, achieving a "zero-carbon computing" supply. The construction cycle was shortened by 70%, and operational costs are 60% lower than those of traditional AI data centers. The first phase includes five pods with a capacity of 1.5MW, expandable to 10MW, creating a benchmark for computing-power integration through innovative models.
In Shanghai, the China Telecom Lingang Intelligent Computing Valley has established an industry-leading, domestically produced, single-pool, ten-thousand-card liquid-cooled intelligent computing cluster. This cluster innovatively adopts a "Rubik's Cube" architecture with a centralized network and layered computing power. It enables high-speed interconnection of ten thousand cards within a single cluster, meeting the demands of training trillion-parameter models for multi-machine, multi-card parallelism and high-throughput, lossless communication. The design allows for functional module decoupling and eliminates the need for mechanical and electrical modifications upon deployment, significantly shortening the delivery cycle. Furthermore, the cluster is fully equipped with a new generation of intelligent computing liquid-cooled DC pods, achieving simultaneous improvements in data center energy efficiency and computing cluster performance, thereby providing intelligent, elastic, and green computing power for "AI+".
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