Offshore wind decommissioning: preparing today for tomorrow’s projects

Over the past three decades, wind turbine technology has made great strides. But now, first-generation offshore wind assets are rapidly approaching the ends of their use cycles. Owners and operators must begin preparing now to decommission their offshore wind turbines safely and sustainably in the near future. 

Tackling risk in wind turbine decommissioning 

Decommissioning onshore and offshore wind turbines poses specific challenges. Owners are examining ways to safely dismantle their turbines and also being mindful of the additional risks offshore with regard to the vessels involved in the removal process and other assets in the vicinity. 

These safety risks are similar to those involved in other offshore decommissioning projects and are linked to key project stages, from planning and disconnection to lifting, loading and transportation. What is different is the number of times each operation must be repeated: the plan for decommissioning a single oil rig will be different from that needed to decommission 15 to 50 wind turbines. 

Marine assurance services are of the utmost importance to minimize risk. Surveys, analyses and inspections all help ensure that removal operations are conducted properly and safely. These assessments, carried out by trusted professionals, improve the efficiency of decommissioning projects. 

Marine warranty services also play a role in preventing mistakes during decommissioning. Bringing in surveyors to conduct risk analyses and assurance will ensure that decommissioning is planned and executed efficiently, from start to finish. 

Embracing circular economy principles 

Environmental impact is one of the most important considerations for decommissioning projects, and circularity plays a key role in reducing it. Whereas today, circularity is a consideration when building new wind turbines, older assets were not always designed with sustainable decommissioning in mind. As a result, many of their materials are not recyclable. 

When decommissioning older wind turbines, the industry increasingly needs to ensure that all components are disposed of appropriately. They are also seeking to minimize the amount of waste produced. Carbon fiber blades, for instance, can no longer be sent to the landfill. New uses must be found for these and other pieces of decommissioned turbines.  

One way to do this could be repurposing and reusing existing assets in future offshore wind farms. Older turbines also tend to be smaller, and operators are exploring how they could be integrated into newer structures. Gravity-based structures, for example, could potentially be reinforced and enlarged to cope with the greater weight and capacity required today. 

Operators are also exploring how other industries could potentially reuse and recycle parts from wind turbines. Innovative uses to date have included footbridges, cell phone towers and cattle partitions in farms. Another forward-thinking idea is to repurpose disused wind blades as structural elements of floating platforms used to carry large photo-voltaic solar arrays.  

The sector needs to design wind turbines with decommissioning in mind. This will mean selecting greener materials from the outset. For example, producing new steel releases three metric tons of CO2, whereas using recycled steel releases as little as 0.4 metric tons of CO2. A circular approach involves finding ways to repurpose steel in offshore wind turbine projects.