Offshore Wind Replaces Coal and Reduces Transmission, Enabling China to Meet the 1.5°C Climate Imperative

China is the world’s leading installer of wind turbines. Attention is rapidly rising in China to the potential of offshore wind. We utilize the SWITCH-China power sector capacity expansion model to explore the transformative role that offshore wind can play in China meeting the ambitious but critically needed 1.5 °C climate objective. We explore alternative energy mixes and analyze the resulting economic and CO2 emissions benefits of offshore wind as a major energy source for China. We find that offshore wind not only replaces coal-fired power plants, which dominate the energy mix in Chinese coastal regions, but also reduces the need for ultra-high-voltage (UHV) transmission lines to deliver the renewable energy generated in the West China to the coastal regions in the East. Offshore wind enables the coastal provinces to become a new hub of green electricity supply, with offshore wind could provide 2 % - 28.6 % of coastal generation (between 1% and 13.2% of total generation) by 2030 across cost-effective energy development scenarios.