Training Design for Construction and Maintenance of Offshore Renewable Energy Facilities

Offshore renewable energy facilities have become increasingly important in the last decade and training for the construction and maintenance of these facilities has developed in parallel. In this first part of a two-part story, SCT’s Mario Pierobon reports on how offshore wind farm construction decisions may influence maintenance training design.

Wind Farm Location

A wind farm or park (either onshore or offshore) is a cluster of wind turbines connected to the power grid, and acts as a single electricity-producing power station, notes Mahmood Shafiee in a 2015 journal paper entitled ‘Maintenance logistics organization for offshore wind energy: Current progress and future perspectives’ [i]. “The design of an offshore wind farm (i.e., geographical placement or layout, location of installations with respect to wind and wave direction) is an important element that can heavily influence the maintenance logistics decisions,” he says. “The placement refers to the position in where wind farm is located (e.g., distance from the shore, water depth) and the layout refers to the arrangement of wind turbines within a wind farm (e.g., shape of arrangement, distance between the wind turbines).”

Floating Wind Farms

Wind farms can also be floating, and the nature of floating wind farms poses a complex challenge for the maintenance strategy but, at the same time, it also offers the opportunity to optimise the business, affirms the World Forum Offshore Wind (WFO) in 2021 white paper entitled ‘Challenges and Opportunities of Major Maintenance for Floating Offshore Wind’ [ii].

Floating wind farms are typically located further away from the shore, and the logistics and workability aspects bring about extensive and prolonged maintenance challenges, according to WFO. “From a technical standpoint, risks and their associated mitigation plans must be considered. From an economic standpoint, the cost of operation as well as the cost of lost revenue from time without electricity generation of the floating system(s) will influence the chosen maintenance strategy,” says WFO.

Smart Wind Farms

Kou L., Li Y., Zhang F., Gong X., Hu Y., Yuan Q., Ke W. in a 2022 academic paper entitled ‘Review on Monitoring, Operation and Maintenance of Smart Offshore Wind Farms’ [iii], affirm that in order to improve the stability of offshore wind farms, to improve the quality and efficiency of operation and maintenance, and to increase the revenue of offshore wind farms, during the construction of offshore wind farms, it is necessary to monitor the marine environment and marine organisms for a long time, and to try to avoid or reduce the impact on the habitats and migration routes of birds, fish, and other marine organisms. “At the same time, the integration of offshore wind farms and marine ranches can be considered to realize the efficient output of clean energy and safe aquatic products, which will be an important industrial mode and future development direction," the researchers say.

Maintenance Accommodations

The location and capacity of maintenance accommodations is an important factor to consider in wind farm design. According to Shafiee, when an offshore wind turbine fails, the first task is to detect and identify the main cause of failure. “Most of the failed subassemblies can be made operational by performing an appropriate maintenance action on-site,” he says. “However, in some instances, it is not possible to rectify all failures on-site due to lack of resources such as special equipment and/or trained workforce. In this case, the failed sub-assemblies are normally shipped to a designated maintenance accommodation for rectification.”

The location of the wind farm influences the need to allocate a number of on-site as well as off-site maintenance accommodations to rectify the failed items, observes Shafiee. “In this case, the location and capacity sizing of accommodations are two key elements playing an important role in effectiveness of the maintenance services,” he says.

Selection of Maintenance Strategy

The selection of an appropriate maintenance strategy for offshore wind farms is a decision for owners and stakeholders to take, and this needs to be considered as part of design. “The decision makers must decide on the ‘best’ maintenance strategy for grid infrastructure as well as for the wind turbines, among a set of possible alternatives,” says Shafiee.

Maintenance strategies for offshore wind farms can be categorised into two major classes, i.e., failure-based (reactive response), and proactive maintenance, according to Shafiee. “The main difference between these two classes is that the former is carried out after the system failure whilst the latter takes place prior to any failure (i.e., before a failure occurs or before cracks propagate to critical length),” he says.

In this article we have considered how offshore wind farm construction impacts on maintenance training design. In the second part of this story, we will focus on the maintenance strategies.

References

[i]

Mahmood Shafiee, Maintenance logistics organization for offshore wind energy: Current progress and future perspectives, Renewable Energy, Volume 77, 2015, Pages 182-193,

https://doi.org/10.1016/j.renene.2014.11.045

[ii]

World Forum Offshore Wind (WFO), ‘Challenges and Opportunities of Major Maintenance for Floating Offshore Wind -’, 2021,

https://www.researchgate.net/publication/357151329_Challenges_and_Opportunities_of_Major_Maintenance_for_Floating_Offshore_Wind_-_World_Forum_Offshore_Wind_WFO

[iii]

Kou, L.; Li, Y.; Zhang, F.; Gong, X.; Hu, Y.; Yuan, Q.; Ke,W. Review on Monitoring, Operation and Maintenance of Smart Offshore Wind Farms. Sensors 2022, 22, 2822

https://doi.org/10.3390/s22082822