Over 25 years ago we moved into the passionate world of wind-turbine foundations. At first, as so often happens, in order to solve the problem of tower–foundation connections via a ferrule, which, with the dynamic loads of a turbine, failed to do its job properly. We understood the behaviour and special characteristics of these structures, so we were able to offer several relevant optimisations to turbine manufacturers of 20–30% of the amounts of reinforcement needed compared with their standard designs.

The scene has now changed a lot, but the needs for ad hoc engineering and fast response are still key factors in reducing energy costs yet further. The power and rotor ratings of turbines on land continue to increase. The volumes of concrete used for shoes have increased threefold in many cases. Much progress still remains to be achieved, from design considerations such as no-gapping to the application of advanced calculations to optimise reinforcement and dimensions. Interaction with the land, adjusting the depths of excavation bases, market-dependent prefabrication solutions, pedestals or types that enable the hub height to be increased are some of the new challenges and targets being faced. With more than 10,000 foundations having been designed by Esteyco over the last decade, we still have a lot left to do.