The main objective of this project is to analyse the technical and economic feasibility of installing a large offshore wind farm (over 50 MW) on the coastline of Tarragona, taking as a reference the large offshore parks in the Nordic countries, as the Middelgrunden in Denmark. Although being one of the European countries with European countries with the most on-land wind plants installed to date, Spain currently has no offshore wind farm in operation, and this has been one of the main reasons that have led to the undertaking of this project: to determine if installing an offshore wind farm at the Catalan coastline is feasible or not. To achieve this goal this project has been divided into two parts: the first is the design of the offshore wind farm, taking into account all the existing regulations as well as several technical criteria to make better use of the wind resource. Actually two power wind plants have been designed for two types of wind turbines to be installed. These two wind farms are compared simultaneously for all the economic aspects. The second part provides an economic feasibility analysis of the facilities designed. This includes the determination of capital and maintenance costs of the park, as well as the determination of the revenues from the sale of the energy produced by both offshore wind farms. Along with these, a cost benefit analysis of the project is carried out. A sensitivity analysis for different parameters of the profitability analysis is also done at the end of the economic feasibility analysis. Finally, this project has analysed how the changes in the law concerning economic compensation for the energy produced by the facilities of the special regime affect the profitability of an offshore wind project.