Economic and social use of the sea has been fundamental in human history. Offshore wind farms are the most recent development and are a major change to the marine environment. They need to safely share the sea with many other users.

Optimising the layout of an offshore wind farm is an iterative process, and adds expense to wind farm development. The Offshore Wind Farm Layout Optimization (OWFLO) project seeks to streamline this process by uniting efficient optimisation algorithms with models of offshore farm costs and energy production. Most software configures farms for maximum energy production, but this does not account for the significant, site-specific costs of components such as the support structure and electrical interconnection. The OWFLO software instead models the levelised production cost to identify the combination of maximum energy production and minimum cost of energy that best suits the site. This article summarises the initial scope and progress of this project and presents a comparison with data from an actual offshore wind farm. The overall energy and cost of energy estimations compare well with the real data, and methods for further improvement of the models are described.

Foundation equipment manufacturer BAUER Maschinen GmbH, a member of the BAUER Group of Germany, was awarded the contract for supplying its Flydrill System BFD 5500 to Marine Projects International Ltd (MPI), together with full technical supervision and operational support for the installation of monopile foundations for the Barrow Offshore Wind Farm site in the East Irish Sea. In this article, the authors describe the system and project.

The article describes work to investigate the effects on tower dynamics when mounting a turbine on a monopile foundation offshore compared to a similar onshore installation. Changes in frequency, mode shapes and damping were investigated, including effects of hydrodynamics and non-linear soil properties. The tool used for the investigation is the new aeroelastic code HAWC2, which is based on a multibody formulation. This formulation is very general, which means that it can handle any structural object (body) as well as large rotations between the bodies and their associated non-linear effects. Thus, for example, complex foundation types such as very flexible monopile foundations, tripod structures and even floating support structures can be simulated in the code.

Motivated by the growing installation of wind energy systems all over the world and with the perspective of wind energy utilisation in Brazil, the authors present a simplified model to evaluate the optimum aerodynamic configuration for the rotor blades of a horizontal axis wind turbine (HAWT). The model is based on the conservation equations and the Panel Method, and a limited set of geometric parameters that strongly affect the rotor aerodynamics are calculated.

By Daniel Fonseca de Carvalho e Silva, Luiz Henrique Gomes Pereira and Gustavo C.R. Bodstein, Brazil