China has achieved a landmark breakthrough in the large-scale commercial development of deep-sea clean energy, as the first batch of turbines for the Yangjiang Qingzhou Phase 5 and Phase 7 offshore wind project successfully connected to the power grid recently.
Featuring the world's highest voltage rating and largest transmission capacity for an offshore wind flexible direct current transmission system, the commissioning marks a decisive step forward in transmitting bulk green electricity across deep waters and long distances.
Developed by China Three Gorges Corp, the massive clean power complex is situated in the waters south of Yangxi county in Yangjiang, Guangdong province.
The project comprises 163 wind turbines with a total installed capacity of 2 gigawatts. Operating at a site center roughly 70 kilometers offshore with in depths exceeding 50 meters, the facility must withstand complex and volatile sea conditions.
The project employs an advanced ±500-kilovolt flexible DC transmission architecture. Electricity generated by the turbines is channeled through 66-kV inter-array cables into the "Heart of Sea Breeze" — the world's largest offshore converter station — where it is stepped up and converted from alternating current into direct current.
The power is then transmitted directly to an onshore central control station via ±500-kV subsea DC cables, representing the first commercial deployment of such high-voltage DC marine cables worldwide, it said.
"Since completing turbine installations in early August, our engineering team has overcome formidable marine challenges, including severe swells, dense salt-spray corrosion, and frequent typhoons," Gu Pengcheng, an engineer at CTG's Yangjiang division, said.
"Successfully synchronizing this initial batch of turbines lays a solid foundation for delivering full-capacity commercial operations as scheduled."
Once fully operational, the 2-GW complex is projected to supply approximately 6 billion kilowatt-hours of clean electricity annually to the Guangdong-Hong Kong-Macao Greater Bay Area — equivalent to offsetting nearly 5 million metric tons of carbon dioxide emissions each year.
(Source: China Daily)