Charges unveiled by two offshore wind sector leaders highlight the challenges the fast-growing renewables industry is facing, ranging from quality issues to cost inflation, that are hitting profit outlooks. Denmark's Ørsted, the world's No. 1 offshore wind farm developer, last Thursday announced a writedown on a large U.S. offshore wind project and an earnings forecast for 2023 that fell short of analyst estimates. Madrid-listed Siemens Gamesa, the world's biggest offshore wind turbine maker, reported a 472 million euro ($510 million) hit to operating profit due to faulty turbine components that require higher warranty and maintenance provisions.