Evaluation of offshore wind energy zones within marine spatial planning: A case study in the Spanish Mediterranean Sea

Offshore renewable energy is gaining attention as a vital component in the battle against climate change. This emerging use of the marine environment is poised for rapid growth, presenting new challenges for ocean management. As a result, marine spatial planning is being developed to designate potential zones for this use, however, these processes often lack important considerations for adequate decision-making. This work evaluates high-potential zones for offshore wind energy within marine spatial planning. This approach is illustrated through a case study in the Spanish territorial waters in the Mediterranean. This work considers port facilities, water depth, availability factor of wind turbines, estimated energy production and, last but not least, the impact of the wave climate on maintenance scheduling. In selecting port facilities, the decision between prioritising proximity or well-equipped infrastructure is crucial - particularly in the Levantine-Balearic subdivision. Water depth, which influences the foundation costs, presents a considerable range across the high-potential zones (100-1000 m), potentially decisive for offshore wind siting. Distinctive wave climates occur in the zones within the enclosed Alboran Sea, leading to a higher number of available windows for essential maintenance operations (-85% of the total). Finally, whereas the availability factor of wind turbines remains consistent across the highpotential zones (-75%), regions closer to the Gulf of Lyon exhibit substantially greater estimated energy production - up to 1.24 times the energy produced in other zones. Given that energy generation is the paramount objective of offshore wind farms, this aspect has the potential to make a difference. This analysis aims to identify the most favourable locations for advancing offshore wind initiatives in the Spanish territorial waters in the Mediterranean, offering valuable insight to support informed decision-making processes in marine spatial planning.