Technology
CNNC Tianwan offshore PV project passes 1 GW in grid-connected operation
Cumulative connected capacity passed 1 GW within the coastal project's overall 2 GW development scope.
On November 3, the reporter learned from the project team for CNNC's 2 GW Tianwan tidal-flat PV demonstration project that cumulative grid-connected operating capacity had exceeded 1 GW. More than half of the project's planned capacity is now in operation, marking an important construction milestone and laying the groundwork for full-capacity grid connection.
The 2 GW Tianwan tidal-flat PV demonstration project is located in the warm-water discharge area of Tianwan Nuclear Power Station in Lianyun District and uses approximately 28,300 mu of marine space. The report describes it as part of China's third batch of large renewable-energy bases, the country's largest offshore PV project, a demonstration of vertically layered marine-use rights and solar-related sea-use policy, and the world's first model renewable-energy project combining nuclear power, heat, solar and storage.
The project uses the surface layer of the sea area, sharing space vertically with the water body already assigned to the nuclear station's warm-water discharge, to develop complementary nuclear and solar generation. The arrangement of PV modules can lower seawater temperature and reduce the environmental effects of the nuclear plant's thermal discharge. It is described as China's first project whose marine-use rights were submitted for approval at an executive meeting of the State Council and the country's largest individual project involving vertically layered marine-use rights. Its use category is electricity-industry marine use, with a 27-year term. Once completed, it is expected to provide more than 2 billion kWh of clean electricity annually.
The project follows an overall construction plan with phased grid connection. Since the first generating units were connected in January 2025, construction, installation, commissioning and successive connections have progressed to scheduled milestones. Cumulative installed capacity passed 1.5 GW in September 2026, supporting the goal of putting 1 GW into grid-connected operation and building experience for further large-scale connections. At the time of the report, 1.63 GW of PV modules had been installed, with overall progress reported at approximately 77%.
To support construction, CNNC New Energy's Jiangsu company led the development of two autonomous underwater pile-inspection robot systems, providing a dedicated underwater inspection capability for this approximately 28,000-mu solar site. Site technicians said more than 60,000 prestressed concrete pipe piles had been installed on the seabed as the project's structural foundations. The robots carry out comprehensive, precise and efficient inspections of submerged piles, supporting safe and stable operation of the offshore PV development.
“The underwater robot needs to carry high-definition ‘eyes’—cameras—and an acoustic ‘stethoscope’—sonar—to approach the piles and scan their surfaces in detail,” said Cui Jinjun, technical lead for the autonomous underwater pile-inspection robot system. “It must also have an AI ‘brain’ capable of analysing images and automatically identifying problems such as corrosion, cracks and biological fouling, with a required accuracy of at least 95%.”
The onshore step-up substation has been completed, and the associated energy-storage station entered full grid-connected operation in June 2024. After the whole project is completed, it is expected to operate for 25 years, generate more than 2.2 billion kWh annually, save an average of 681,200 tonnes of standard coal per year and reduce carbon dioxide emissions by 1.77 million tonnes, continuing to supply green energy for local economic and social development.