OFFSHORE. Wind farms at sea are known internationally as being offshore, separating them from those on land.

OHSAS 1800:2007. Standard establishing the minimum requirements in company management systems for health and safety.

ONSHORE. Referring to land-based wind farms.

OPERATION AND MAINTENANCE. Maintaining, in an operational state, the existing structures, systems, etc., as well as evaluation of the costs of these works.

OPERATIVE EXPERIENCE. Knowledge of a process based upon experience.

OVER-EXPLOITATION. Extraction of a natural resource at a rate higher than that of regeneration, which may lead to the exhaustion of the resource.