Project Description:
(I) Strategy: Cater to both short-term and long-term regional development needs and build China's first integrated project of "island power supply + green power transmission"
Weizhou Island has long relied on gas and diesel power generation, which is characterized by insufficient power supply capacity, high costs and high carbon emissions. In addition, frequent power outages caused by typhoons and other extreme weather have severely restricted the improvement of people's livelihood and the development of the tourism economy. Meanwhile, the Beibu Gulf is rich in offshore wind power resources, but their development is hindered by the lack of transmission channels.
Adopting the construction concept of "island power supply + green power transmission", this project meets both the short-term power supply guarantee of Weizhou Island and the long-term demand for clean energy consumption. It is highly aligned with China's "dual carbon" strategy and the development direction of the new power system, and has obtained strong support from the government, setting a successful example for the construction of island energy infrastructure.
The project integrates the Internet of Things, artificial intelligence and digital twin technologies to build a 3D digital intelligent operation and maintenance system covering the entire links of "power transmission, transformation and distribution". It realizes real-time perception of power grid status, intelligent inspection, remote operation and risk early warning, and enables panoramic monitoring and intelligent analysis of submarine cables, substation equipment and distribution networks. This significantly improves the reliability, operation and maintenance efficiency, and fault response speed of the power grid, representing the development direction of future high-resilience and intelligent power grids.
At present, the project has been reported in an open and transparent manner by national-level media (such as CCTV News Network), and community communication activities are actively carried out to ensure that the public fully understands the significance of the project. The "Weizhou Model" formed by this project provides a replicable "island smart grid solution" for coastal and island regions around the world with similar geographical conditions to solve off-grid power supply problems, enhance energy resilience and support renewable energy consumption.
Figure1 3D Intelligent Operations and Maintenance System – Main Interface
Figure2 3D Intelligent Operation and Maintenance System – Transmission Monitoring
(II) Measures: Focus on tackling key core technologies and achieve multiple "first-ever" breakthroughs in the project
The project was advanced to high standards and strict requirements during implementation, overcoming a number of technical challenges and achieving the unity of ecological friendliness and engineering excellence.
First, it applied China’s first 220kV submarine cable using domestically produced cross-linked polyethylene (XLPE) insulation materials. The project adopted a "land cable + submarine cable + land cable" construction mode, with 44.5 kilometers of newly built submarine cables, making it the longest single 220kV submarine cable in China to date. Previously, insulation materials for submarine cables were all imported; this project marks the first time in China that domestically made insulation materials and intermediate joints were fully applied to one phase of a 220kV three-phase submarine cable. As a model project for the application of major first-set technical equipment in the energy sector, it has realized the localization of insulation materials for long-distance submarine cables and broken international monopolies.
Second, it employed the longest horizontal directional drilling (HDD) for 220kV submarine cable installation in China, achieving zero conflict between submarine cable laying and coral reef protection. To protect the coral reefs around Weizhou Island, a long-distance HDD was used to cross the coral reef area from beneath the seabed for cable landing on the island, effectively safeguarding the coral reef ecosystem. With a length of approximately 830 meters, this HDD ranks as the longest for submarine cable projects in China at present. To reduce the difficulty of cable pulling, a drag-reduction device was innovatively developed, and the selection and design of non-excavation pipelines were optimized, with the effectiveness verified through tests.
Third, it built China’s first island substation designed to the highest typhoon resistance standard, tailored to the extreme climatic conditions of Weizhou Island. Through specialized and in-depth design, the building curtain wall achieves a wind pressure resistance rating of Level 6, capable of withstanding super typhoons of Category 17 or above, thus establishing a solid safety barrier for island power infrastructure.
Fourth, it adopted the first-ever "equivalent-strength steel-to-copper non-magnetic armoring" technology for submarine cables. The staggered welding technology for "steel-to-copper" single wires in cable armoring was applied, which not only achieves non-magnetization of the armoring in the bottleneck sections at both ends of the project to improve current-carrying capacity, but also meets the basic requirement of maintaining the mechanical strength of the submarine cable armoring in the transition sections. This innovation effectively reduces the conductor cross-section of the entire submarine cable line and significantly cuts down submarine cable procurement costs.
Fifth, it implemented the first integrated protection scheme of "channel dredging + submarine cable jetting burial + covering burial", realizing zero ecological disturbance. The submarine cable route of Weizhou Island is relatively complex, passing through the Weibei natural gas pipeline, the 300,000-ton-class shipping channel, and marine ecological reserves. Prior to construction, detailed seabed surveys were conducted using sub-bottom profilers and multi-beam echo sounders. To avoid impacting submarine pipelines, anchorless construction methods were adopted for all submarine cable laying works except for the landing point operations. Moreover, multiple innovative protection measures were applied, including directional drilling, deep burial, cement weight coating, and composite casing pipes, achieving a harmonious win-win situation between project construction and ecological conservation.
Sixth, it pioneered the anti-sediment diffusion protection technology using pollution barriers in coral reef protected areas. The sediment diffusion prevention scheme was optimized through numerical simulation, and pollution barriers were installed in the sections adjacent to coral reefs, effectively blocking construction-related pollution. In addition, the positive reaming technology on the mainland side was adopted for the land-sea directional drilling on the Weizhou Island side, enabling the recycling of HDD slurry for borehole stabilization and zero slurry discharge into the sea. This provides a technical template for similar marine ecological protection-oriented projects.
Figure 3 Underwater cable laying illustration
Figure 4 Offshore cable laying platform
Figure 5 View of the offshore cable laying site
(III) Sharing: Deepen the Extension of Social Value and Build a Sustainable Project Ecosystem Featuring Community Participation, Cultural Integration and Gender Equality
First, humanized measures such as off-peak transportation and homestay communication mechanism were implemented during the construction period to minimize the impact of construction on local livelihoods. In addition, priority was given to local islanders in filling some logistics service positions. During the construction process, the project strictly complied with local island regulations and folk customs, and paid close attention to protecting the local environment and culture. Representatives from the Weizhou Island Administrative Committee and local residents were invited to board the cable-laying vessels to observe the hard work of power grid constructors on site, thus earning the sincere endorsement and strong support of the local government and residents.
Second, the project cared for industrial workers to pool maximum strength for construction. It provided well-equipped workers' dormitories, canteens, and fitness and rest facilities to improve the living conditions of industrial workers. A Model Base for Industrial Workers was established to promote local employment and skill upgrading. The dividends of the project have widely benefited residents, the environment and enterprises, fostering a resilient community-industry symbiotic system.
Third, an innovative facade design themed "Silk Road on the Sea Shimmering with Light" was adopted. The design uses modern architectural language to express the fluidity of the ocean and light, showcasing the historical and cultural elements of the Maritime Silk Road and the profound heritage of marine civilization in the Asia-Pacific region.
Fourth, the project actively recruited female technical backbones to participate in key work sections, covering critical fields such as submarine cable technology and digital systems. It also launched public welfare initiatives including "Power Crosses the Sea to Bring Light, Golden Autumn Student Assistance to Fulfill Dreams", donating learning supplies to more than 600 students at Weizhou Island Experimental School. With energy infrastructure as the link, the project empowers the growth path of the next generation, especially young women.
Figure 6 Improve the living comfort of industrial workers
Figure 7 Donation of School Bags and Stationery to Children
Figure 8 The Facade of Weizhou Substation Is Designed with the Concept of "Silk Road on the Sea Shimmering with Light"
(IV) Outcomes: From Stable Power Supply to Intelligent Operation and Maintenance, Creating a Replicable Model for Island Energy Transition
First, it empowers livelihood improvement and serves as a "public-centric project" that enhances people's sense of well-being. After completion, the power supply capacity of Weizhou Island will surge from 35,000 kW to 161,000 kW, while residential electricity prices remain stable without any increase due to infrastructure upgrading. In the future, Weizhou Island will have access to power from the mainland grid around the clock, completely resolving the long-standing power shortage issue affecting 25,000 local residents. It will ensure the reliable operation of critical infrastructure such as hospitals, schools, water supply systems and communication networks, and meet the electricity demand for Weizhou Island to accelerate its development into an internationally renowned leisure and vacation destination.
Second, it supports ecological protection and acts as a "green project" that safeguards the most beautiful island. The project can accommodate the grid connection demand of offshore wind power in the Beibu Gulf. After commissioning, it will reduce carbon dioxide emissions by 4,318 tons annually, equivalent to planting 230,000 trees, effectively contributing to the achievement of regional "dual carbon" goals. Adhering to the fair principle of "shared development and joint ecological protection", the project has earmarked a special environmental protection fund of 31.2913 million yuan through an ecological compensation mechanism—the highest amount among similar projects in China—for the protection of aquatic germplasm resources in the Beibu Gulf, realizing a positive interaction between project construction and ecological restoration. While responding to the global trend of energy transition, it has provided an inspiring and operable policy model for island energy system construction in the Asia-Pacific region through transparent public communication (via national media coverage and community engagement activities) and the replicable "Weizhou Model".
Third, it deepens digital empowerment and emerges as a "smart project" that is replicable and scalable. As China’s first 3D intelligent operation and maintenance system integrating cross-sea interconnection, power transmission, transformation and distribution, the project achieves millimeter-level perception of equipment status, automatic fault diagnosis and intelligent inspection. This has improved operation and maintenance efficiency by over 70% and reduced labor costs by 65%. These outcomes are supported by verifiable data: 1 construction method, 1 utility model patent and 1 QC (Quality Control) achievement have been finalized; 19 invention patents are under application; and 10 papers have been published in EI-indexed conferences. The project has also been transparently showcased to the public through national media platforms, including special documentaries on CCTV News Network and CCTV-4 Across China, forming a comprehensive influence model that integrates energy security, ecological protection and technological innovation.