The number and size of available offshore wind vessels will hobble China’s offshore wind growth this year and next, despite a rate of expansion that will see the nation contesting top spot in global installations as soon as 2021, a leading turbine manufacturer told an industry conference.

China could be more than 30 vessels short of the fleet needed to serve its red-hot market, a deficit that's adding as much as 12% to the cost of building projects, said Miao Jun, president of Shanghai Electric Wind Power Group (SEWC), China's offshore turbine market-leader.