Abstract: This paper will focus on several matters related to off-shore wind energy, on the basis of the experience that IDOM has gained during the development of previous works done for Public Administrations and private promoters in several places along the Spanish coast, such as:

• The reasons why “nowadays the off-shore wind energy is not a priority for the Spanish Energy sector”
   
• Several opportunities that may lead to look for a favourable position and invest in this energy sector.
   
• Uncertainties that may condition its future development.
   
• Key Issues in the construction of an off-shore wind farm

A brief description of the potential effects and the environmental impact of this kind of energy infrastructures will be considered, with some examples developed in other European countries. 

Finally, a description of some works made by Idom will be shown.