China has recently marked a significant leap forward in the electricity transmission sector with the completion of the 800 kilovolt UHVDC Baihetan – Jiangsu project on May 20, 2022. Implemented by the State Grid Jiangsu Electric Power Company (SGJEPC), this project spans 2,080 kilometers, transmitting power from the Baihetan Hydroelectric Station in Sichuan to Jiangsu, with a capacity of 8,000 MW. It is one of the projects utilizing advanced technologies such as 3D printing, unmanned aerial vehicles, and AI in design, construction, and operation management, delivering superior efficiency.
Commenced in late 2020, the project is part of China’s West-East Electricity Transmission Program. Upon its operational start later this year, it is expected to supply over 30 billion kWh annually, reducing CO2 emissions by more than 25 million tons per year. This pioneering initiative contributes to China’s green electricity transmission trend, enhancing renewable energy production capacity. From 2021 to 2025, several UHV transmission projects will be constructed in Northwest and Southwest regions, with an estimated total transmission capacity potentially reaching 56,000 MW.
In addition to the Baihetan – Jiangsu project, the State Grid Corporation of China (SGCC) owns several other notable UHVDC lines, including the 3,324 km Changji – Guquan project. Starting from Changji Station, it traverses multiple provinces and cities, concluding at Guquan Station in Xuancheng city. Its primary goal is to transmit electricity from sparsely populated Northwest regions with surplus power to densely populated East regions like Beijing and Shanghai, while promoting development in underdeveloped areas in the Northwest and reducing coal consumption from Eastern power plants.
UHVDC transmission technology has been applied in China since 2009, enabling the transmission of both alternating current (AC) and direct current (DC) over vast distances. With this expansion, China has become a global leader in electricity consumption. In 2021, China produced 8,312 billion kWh of electricity, double that of the United States, with an installed electricity generation capacity of 2,240 GW, nearly double that of the United States. Particularly, China’s solar power capacity has exceeded 306 GW, accounting for 18% of the total national electricity capacity.
UHVDC technology allows for the transmission of enormous electricity volumes over extremely large distances, overcoming traditional barriers in the electricity sector, especially for clean and renewable energy sources like hydroelectric, wind, and solar power. Currently, China has constructed approximately 34 UHVDC transmission lines, with 5 other projects in the construction phase, reducing transmission losses and stabilizing the electricity system.
UHVDC technology raises the voltage from standard HVDC ±500 kV to ±800 kV, reducing transmission losses from 10% to 7%. This makes electricity production feasible in remote areas, particularly in countries with abundant but untapped hydroelectric power.
UHVDC not only saves costs but also reduces corridor requirements, meeting stringent electromagnetic field requirements, making this technology attractive for electricity transmission projects. However, there are debates regarding the security, reliability, and economic efficiency of these projects.
In Vietnam, aiming for carbon neutrality by 2050, HVDC technology is considered a potential option for developing environmentally friendly electricity sources such as wind and solar power. With HVDC projects, Vietnam can reduce transmission losses, save costs, ensure national energy security, and enhance technological capabilities in the electricity transmission sector.
UHVDC technology represents a significant step forward, opening up sustainable development opportunities for both China’s electricity industry and other countries, towards the goals of reducing carbon emissions and enhancing renewable energy utilization in the future.