Monopiles in offshore wind: Preliminary estimate of main dimensions

Abstract

Offshore wind industry is having a great development. It requires progress in many aspects to achieve the sustainable progress of this technology. One of those aspects is the design of foundation, sub-structures and support structures. The most used at present, with more than 80%, is the monopile. Typical piles used in quays in maritime engineering have a maximum diameter about 2 or 3 m. In offshore wind, the diameter can be more than double. There is a risk associated with the difference in scale. Some formulas used for the design of typical piles with diameter less than 2 m can be unsuitable for larger diameter piles. This paper is focused on giving a first estimate of length and weight of piles for knowing its diameter. There are formulas for that for piles with diameters up to 2 m, but there are doubts about whether they can be used for piles with larger diameters. To achieve it, a database gathering offshore wind farms in operation with monopiles is prepared in order to obtain simple formulas relating those parameters. Furthermore, the results of that formula are compared with traditional formula used in maritime engineering for piles with diameters less than 2 m.