Offshore wind is a zeitgeist technology in the transition from fossil fuels to low-carbon power sources. The way the industry has scaled up and innovated relentlessly, particularly over the last decade, is breathtaking. Some 4.5 gigawatts (GW) of new offshore wind capacity was installed last year, bringing the global total to 23 GW – enough to meet the annual electricity needs of more than 20 million homes a year. Quite an achievement given that there was next to nothing installed before 2000. This extraordinary expansion is set to continue worldwide, A growing number of countries are harnessing the immense, consistent, predictable and affordable power of wind at sea. Given that 70% of the world is covered by water; the majority of the global population live less than 50 km from the shore and the best wind conditions travel across the world’s oceans – we may wonder why we have not captured this resource sooner. The difference, like with onshore wind and solar, is that through greater deployment we have seen dramatic cost reductions, beating fossil fuels in many markets today. Even beyond the established North Sea offshore wind countries (including the UK, Denmark, the Netherlands, Germany and Belgium) we see strong growth also from the US East Coast, China, France, Taiwan, South Korea, Japan and Baltic countries. This business is getting seriously global – but the world leader is the UK, with 7.9 GW installed across 36 projects, generating 8% of the country’s annual electricity needs. The UK is a record-breaker in a number of ways. It hosts the biggest offshore wind farms in the world, including the largest (Walney Extension, off the coast of Cumbria, with a capacity of 659 megawatts (MW), powering 600,000 homes a year), and the most powerful commercially available turbines (each with a capacity of 8.8 MW, in Aberdeen Bay, nearly 200 m tall). The future pipeline of offshore wind projects in UK waters is strong, with three more under construction (adding 2.5 GW), a further 15 consented (12 GW) and five others in planning (5.3 GW), totalling 27.7 GW. A new round of UK seabed leasing is due to take place this year, ensuring a sustainable pipeline of projects for the 2020s and 2030s.