Wind farms in UK waters come with histories before they come with turbines. The Westermost Rough site was originally awarded in 2003 to the French oil major Total during the Round 2 tendering process - the second wave of UK offshore wind leases issued by the Crown Estate. Total studied the project, did the early-stage assessment, and concluded it did not fit their portfolio. They returned the concession to the Crown Estate in 2006. The Danish energy company DONG Energy - through a UK subsidiary - took it on. A planning application went in during November 2009 for between 35 and 80 turbines of 3 to 7 MW each, in a 35-square-kilometre site, with a total installed capacity of up to 245 MW. The final build came in just under that ceiling: 35 turbines, 210 MW of capacity, operational from May 2015. For the small communities of the Holderness coast, this was a new industry threading itself onto a shoreline already lined with the chimneys of the old ones.

Westermost Rough's significance to wind engineering is small but real: it was the first commercial wind farm anywhere in the world to use Siemens' gearless 6 MW turbines. A conventional wind turbine has a gearbox between the slow-turning rotor and the fast-spinning generator. The gearbox is mechanically essential but also the part most likely to fail expensively in mid-North-Sea conditions - the helicopter crane-down to swap a failed gearbox is one of the most miserable jobs in offshore O&M. A direct-drive turbine eliminates the gearbox entirely. Siemens' SWT-6.0-154 placed the generator on the rotor shaft and let the magnetic field do the work. Heavier in the nacelle, simpler in maintenance. The offshore substation was installed by June 2014. By May 2015, Ofgem had named Transmission Capital Partners as preferred bidder to own and operate the wind farm's electrical transmission assets - the OFTO model that splits ownership of the generation from the export cables to shore.

In 2017, DONG Energy renamed itself Orsted - after the Danish physicist Hans Christian Orsted, who in 1820 discovered the connection between electricity and magnetism that makes every generator work. The reason for the renaming was more prosaic: DONG stood for Danish Oil & Natural Gas, and the company had spent the previous decade methodically divesting every oil and gas asset it owned, racing toward a portfolio that would be effectively 100 percent renewable. A name advertising oil and gas no longer fitted what the company was. Westermost Rough went into the Orsted UK portfolio along with much of the rest of the British offshore wind fleet. Today Orsted is the world's largest developer of offshore wind, and its UK operations - administered partly from Grimsby just down the Lincolnshire coast - have helped reshape the Humber's economy from petrochemicals toward clean energy.

Thirty-five turbines in a North Sea swell are an oddly delicate-looking thing. From the beach at Withernsea on a clear day you can see them as faint white verticals on the horizon, slowly turning. Closer in, they are huge: the rotor of a Siemens 6 MW spans 154 metres, more than the wingspan of any aircraft built. On a windy day each turbine puts out enough power to supply roughly 5,000 UK homes. On a still day, none of them do anything at all. Below the waterline, the steel monopile foundations have become artificial reefs - colonised by mussels, hydroids and the small fish that follow them - in a sea otherwise scoured fairly clean by trawling. Above the waterline, navigation lights blink at night. Below the surface, somewhere not all that far away, sits the wreck of SM UC-75, a German U-boat sunk in 1918, in waters that now belong to the wind.