China Southern Power Grid (CSG) plans to invest approximately 5.7 billion yuan ($791.73 million) to construct the 500 kV main grid project as the backbone of the province's future power grid. The project is included in the country's 14th Five-Year Plan (2021-25) for power development and stands as one of the major projects for the construction of the Hainan Free Trade Port.
The project includes four sub-projects: the Yecheng transmission and transformation project, the Changhua transmission and transformation project, the Sanya transmission and transformation project, and the Changjiang nuclear power phase II access system project. It involves the construction of three new 500 kV substations, 838 kilometers of 500 kV transmission lines, and the construction of 220 kV lines of supporting projects. The project is planned to be completed and put into operation in 2025, forming a complete "mouth"-shaped ring network structure passing through 14 cities and counties, including Haikou, Sanya, and Changjiang. While meeting the power supply needs of Hainan, the project will also promote the safe delivery and consumption of large-scale offshore wind power and high-capacity nuclear power. It will satisfy the power demand for the accelerated construction of the Hainan Free Trade Port, support the construction of a new electric power system, and serve green transformation and development.
The Hainan 500 kV main grid project will be built as a demonstration project for the construction of digital power grids of the same capacity. During the construction process, the 500 kV provincial digital power grid is integrated with the physical power grid in terms of design, construction, and operation. It will adopt digital technologies such as cloud computing, big data, IoT, mobile internet, AI, and blockchain throughout the entire lifecycle of planning, design, construction, operation, and maintenance, achieving full-process digital management and control.
To effectively implement environmental impact prevention and control, the environmental impact assessment team and the design team of the Hainan 500 kV main grid project have conducted on-site inspections of substation sites, transmission towers, and various key facilities, while maintaining a focus on ecological protection, electromagnetic environment, water environment, sound environment, soil and water conservation, and other environmental protection requirements. This is done under the guidance of the Department of Ecology and Environment of Hainan and the provincial radiation station. Through on-site inspections, the teams have also conducted research on land resources, water resources and biodiversity, and taken corresponding avoidance and protective measures.
The project also embodies the philosophy of green development in substation construction and transmission line design. For example, the exterior of the Changhua substation will be decorated in the style of the Li ethnic group, and some of the transmission towers will adopt the shape of coconut trees, aiming to integrate the project with the natural scenery and cultural atmosphere of Hainan.
It is estimated that by 2035, Hainan will have cumulatively built seven 500 kV digital substations, gradually improving the island-wide 500 kV grid structure. This will provide strong impetus for increasing the proportion of interprovincial clean energy consumption in Hainan, as well as for accelerating the transformation and upgrading of China's electric power system.
