Imagine the scene. A Hollywood movie set in the US in the 1950s. A foreman climbs onto a box in a depressed industrial area and announces loudly: “I need brave willing individuals to travel far away and work hard. The financial rewards will be deserved”. Well, this is more or less what happened recently in the US’s wind sector. A few months ago, the foreman on duty was asked: “What needs doing and where?”, and he replied: “Fixing windmills in Spain”.
This was how teams of American workers who had only ever seen a wind turbine on TV before ended up in Spain to work on maintaining the country’s legion of wind farms. Because that just what anyone would do, right?
This reporter was told this story by the head of a Spanish company specialising in wind farm maintenance and, judging by the results of our survey, it is conceivable that it is quite true. Why? Because, in general, our research shows that wind farm owners and operators are quite critical of the work being conducted by maintenance companies.
Despite Spain boasting a large and mature wind industry (21,673 MW of installed capacity covering 16% of total electricity demand in 2011 and employing over 30,000 people), this is the first time a survey of this type has been conducted there. In other countries, however, such surveys are common. For example in Germany, the German Wind Energy Association (BWE) has spent years conducting very detailed surveys with wind farms operators on the quality of maintenance and repair services provided by turbine manufacturers and other ancillary businesses that offer these services. The results are published annually by the magazine New Energy, edited by BWE.
The findings of the German survey in 2011 indicate that maintenance work "seems to have been neglected in recent years during the wind power boom". It also highlights that there is very little information about the quality of the maintenance services provided because no developer is happy to reveal that their machines have experienced a breakdown or malfunction. Silence is golden. No-one says a word, but everyone would like to know how their peers are faring.
Few operators, even less information
There are two substantial differences between the survey conducted by BWE and the one we have conducted. The German Wind Energy Association only consists of wind farm owners, or more accurately, wind turbine owners. However, while a score of companies monopolise around 85% of installed capacity (with just six companies accounting for two thirds of the total) in Spain, there are many thousands of owners in Germany – many of them small, with one or two machines on farms or industrial sites.
Moreover, the Spanish sector associations – the Spanish Wind Energy Association (AEE) and APPA Wind – are made up of wind farm owners, turbine manufacturers and maintenance service companies; making it difficult to discuss the issue of maintenance service quality openly.
With this in mind, Energías Renovables set out to make a first attempt to gather data which are not easy to come by, but which are of great interest to the sector, given that "maintenance work accounts for 20% of total project costs, including the initial capital investment,"explains Alberto Ceña and Emilien Simonot, from AEE’s Technical Department .
Another key issue worth clarifying is that a wind farm’s age is a very important variable that has not been taken into account in this first survey. The German surveys group wind turbines into three categories: those that are still under warranty, those less than 6 years of age and finally, those of 6 years and over. It is estimated that nearly 50% of installed capacity in Spain is now out of warranty; just the time when decisions must be made on the options affecting a wind turbine’s maintenance schedule until the end of its useful life.
Ceña and Simonot report that "70% of the current maintenance market is structurally dominated by wind turbine manufacturers", although this is expected to change and allow more room for other service companies to enter. Another point worth noting is that the BWE survey in 2011 found that independent maintenance and repair service providers achieved better grades than wind turbine manufacturers. As shown in our survey, this is also true in Spain.
How the survey was conducted
The survey was sent to a dozen companies operating wind farms, of which eight responded. It was an anonymous survey, with the names of companies responding to the survey being kept a secret. That said, logically the turbine manufacturers and other companies about which the questions on maintenance services were asked are revealed.
Respondents were asked to score each question with a number from 1 to 5, with 1 being the lowest value and5 the highest. The results of the survey show the performance of eleven companies, six wind turbine manufacturers and five maintenance companies; as these were all rated by at least two wind farm operators.
Another point to consider is that the “other wind turbine manufacturers” heading includes several that no longer exists because they were acquired by other companies. These include Made, purchased by Gamesa, Bonus asquired by Siemens, Ecotècnia that was bought by Alstom, and NEG Micon acquired by Vestas.
Conclusions
As already mentioned, one of the most noteworthy findings is that the average score of independent maintenance service providers is better than that of turbine manufacturers. That said, however, even independent maintenance service providers score poorly or quite poorly on the issue of reporting to wind farm owners what work has been done and why. It is at the moment of disclosing what has been done and why that wind turbine manufacturers are rated worse.
Wind farm operators only just gave the thumbs up on the value of the preventive maintenance provided by turbine manufacturers, with a score of 2.5. This score improved to 2.8 for unscheduled repairs, while independent providers received an average of 2.6 and 3, respectively, on these questions.
Only one turbine manufacturer, Enercon, received a top score in some of the questions, including the last one, number 14, asking for a general assessment: Do the wind turbines perform as expected? All manufacturers passed on this question, which we obviously did not ask with regard to other maintenance service firms.
The full results of the survey are provided on page 29 of the digital version of Energías Renovables, and it is likely that Energías Renovables will follow up this first “feeler” survey with more detailed surveys moving in the future.
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