Offshore wind industry has greater growth potential, since the wind resource is 30 - 50 percent higher at sea than on land. The infrastructure required for the installation of an offshore wind farm is more complex than on land. Today we will see how to carry out maintenance and repair work on the different structures that make up an offshore wind farm.

TURBINES

Turbine maintenance processes are important to ensure their long-term productivity. The activity is divided into preventive maintenance (scheduled) and corrective (unscheduled) work. Most preventive work will typically be carried out during periods of low wind speed to minimize the impact on production. However, in practice this is not always possible.

Corrective service is performed in response to unscheduled outages and is often considered more critical due to the accumulation of downtime until the failure is resolved.

Typical maintenance includes inspection, bolted joint verification, and replacement of worn parts (with a shorter service life than project life).

Unscheduled interventions are in response to events or failures. These can be proactive, before the failure occurs, for example, by responding to condition monitoring inspections or reagents (after a failure has occurred that affects generation).

BLADES

Inspection and repair of shovels consists of inspecting the condition of the blades and replacing or repairing them in a timely and cost-effective manner. Issues such as leak edge erosion have been the source of availability problems in the industry and proactive blade inspection and its preventive repair is now widely pursued in response.

FOUNDATIONS AND ANCHORS

Foundation inspection and repair identifies and addresses corrosion and structural problems above and below the waterline.  Maintenance consists of visual inspections, non-destructive testing (NDT) and seabed inspection work, and repair service work is completed when needed. Inspections focus on structural integrity, lifting, safety equipment, corrosion protection, and protection against undermining.

Regular inspections are required on secondary steel structures such as stairs, gates, and platforms. In some places, it is necessary to clean to remove guano from seabirds, which can be a serious danger to health and safety.

Inspections and surface studies include internal monopile inspections of cement or bolted connections and splash zone inspections. Activities requiring underwater operations may include in frequent structural cathodic protection inspections and weld inspections.

Diving is necessary only in exceptional circumstances and efforts are being made to maximize the use of safer remote techniques.

OFFSHORE SUBSTATION

Maintenance and service of the offshore substation consists primarily of non-intrusive inspections of upstream switchgear and transformers, transformer oil sampling, inspection of foundations and upstream structures and the resulting infrequent service interventions..

Sources:

Pedro Pérez Gabriel: Eólica offshore: Tecnología energética con alto impacto en empleo, I+D+i para la industria y en la transición energética

Guillem Candelas González: Diseño de un aerogenerador offshore con soporte jacket

Lorenzo Bernieri Kossmann: DISEÑO Y CÁLCULO DEL SOPORTE DE UN AEROGENERADOR MARINO DEL TIPO JACKET