The Irish Sea has cost many lives. Their storms are notorious; its bottom is lined with countless shipwrecks and boats. But today it shows its gentle side: the pale blue sea shimmers smoothly in the weak winter sun. Every few hundred meters, huge, white wind turbines protrude up to 200 meters out of the water. Their rotor blades, as high as church spiers, rotate synchronously in the light west wind. 189 wind turbines generate a peak of 1,100 megawatts of electricity, as much as ten coal-fired power station blocks. The technicians at Walney, the world’s largest offshore wind farm, are satisfied: the cameras on their maintenance drones show no damage.