The increasing age of wind farm assets all over Europe poses some very significant questions to the industry, both technically and politically. Regardless of how far we think we have come in terms of wind being accepted as a clean, commercially attractive and vital part of the energy mix, how we deal with these old assets over the next few years will determine our legacy. Based on our experience recommending end of life strategies for wind farms, a number of key lessons can be learnt.

Ultimately, as an owner, it is all about the money. One of the most important aspects of our end of life work in this area has been about showing the financial impact of engineering decisions. This is not just about overall returns – clarity on the detail of when spend is needed is also vital. Cashflow, right down to monthly increments, is often required to fully evaluate options.

Presenting multiple options with complicated outcomes and milestones in a clear and actionable way is a skill we have refined considerably in the last year.

Every site has its own specific issues, especially in the planning and political aspects. Many issues are well known and are often ongoing, but we have learned not to be surprised by what lies buried in your own original planning consents or in those of your immediate neighbours. Indeed, future plans of your immediate neighbour can have a significant effect on your own ambitions. No wind farm is an island!

In areas where wind farms have been contentious there can be a significant amount of effort required to get positive responses to end of life solutions such as life extension or repowering proposals. The lead time on this should not be underestimated.

There can be a lot of emphasis placed on the theoretical analysis. How much “life” have the turbines used up, compared to their original design? While this is a technically intriguing question, in many circumstances it can be difficult to answer with any certainty due to the appropriate data being either unavailable or of poor quality. Many things need to be in place – from the aerodynamic model of the turbine to accurate history of the meteorological conditions at each turbine; from knowledge of the manufacturing process to the full history and provenance of all the parts, including their maintenance records. It is not unusual for wind farms to change owners several times over the course of their 20+ years, and it is easy to lose a lot of this crucial information. Targeted and high quality inspection routines can go a long way to redressing this problem, and we have worked hard with life-extension clients to find ways to address missing data without compromising the clarity of the results.

As a final thought on decommissioning . . . by 2005, there were about 40 000 operational turbines in the Europe with an average rating of just under 1MW. If we assume an average blade length of 25m, that is 3 000km of blades – roughly Paris to Moscow! Looking at our ability to be a true zero-waste industry is something BVGA is passionate about and will be the subject of a later blog.


Graham Gow