Proposal for a programme of periodic inspections for preventive maintenance of offshore monopiles

Abstract

Offshore wind energy is a key technology for the European Union's decarbonisation strategy. To boost its growth, it is essential to further develop the know-how in some areas. To this end, the foundation is the most important structural element with the greatest economic impact on the project. An adequate maintenance strategy is necessary to guarantee its structural integrity over time.

This article proposes a programme of periodic inspections for preventive maintenance of offshore monopiles. The proposal is supported by an extensive review of the existing applicable regulations of the offshore wind industry and other sectors, and a detailed survey of the most common damages in monopiles.

As a result, five inspection levels are defined. For each level, the main objective of the inspection, the scope of works for each foundation element, the intervals and some of the necessary equipment and testing techniques are described.

To complete the proposal, a full inspection program is developed for the entire service life of a monopile.