What is the useful life of wind turbines?

The first wind farm built in Spain dates back to 1984 in the municipality of Garriguella (Girona) and since then there has been non-stop construction of wind farms until now there is a total of 1,298 wind farms throughout the country. They are obviously not all are in the same conditions of maintenance nor do they have the capacity to produce the same volume of energy.

Over the years, technologies become obsolete. For example, in Spain, more than 36% of wind turbines are more than 15 years old. To guarantee the highest quality in production and continue committing to sustainability, work increasingly focusses on repowering.

What does the repowering of wind turbines consist of?

According to the Wind Energy Business Association, "repowering is understood to be the modification of a wind farm that involves the total or partial replacement of wind turbines or any of their main elements, in order to increase production."

Repowering installations using renewable energy for electricity production is an ideal option to rapidly increase renewable energy production with the least impact on grid infrastructure and the environment. It enables plants with significant renewable energy potential to continue to be used and reduces the need to designate new sites for new installations.

There is no doubt that repowering can enable energy policy targets to be reached that seek to meet 35% of energy demand with renewable sources by 2030. In December, the Ministry of Ecological Transition and the Demographic Challenge launched a call valued at €222.5 million for wind repowering, mini-hydraulic renovation and recycling of wind turbine blades.

More renewable energy production with more modern, efficient wind turbines

Even though authorisations to operate wind farm are generally granted without a predefined purpose, the installation needs to be regularly inspected to ensure that they comply with minimum production and environmental impact. It is during this review process that repowering is usually undertaken to maximise production.

Depending on the technology and the date of construction, repowering is usually undertaken when the wind turbine has been operating for between 25 and 30 years. In this regard, it is estimated that between 2023 and 2026 there could be a potential of 3,000 or 4,000 MW and that in 2030 there will be 12,000 MW more than 25 years old.

All the possibilities for repowering in Spain

Depending on the wind farm and the age of the installation, repowering processes can achieve twice the production or more while reducing the environmental impact. So it is important to promote this process and to update installations that are becoming obsolete.

The fact is, repowering has arrived relatively late to Spain compared to other countries. For example, between 2012 and 2016 there were virtually no renovations. But now there is greater awareness and institutions are providing aid and making it easier for more and more wind farms to be developed in order to achieve maximum efficiency.

One of the most recent examples with regard to Endesa's wind farms is the Arinaga wind farm, in Gran Canaria, where six 660 kW wind turbines have just been replaced by others of 900 kW with more advanced technology and smaller dimensions. This investment has made this wind farm the most modern in the Canary Islands.

When a wind turbine stops working

To update a wind turbine that has become obsolete, you need to take a series of steps and follow protocols that in many cases make the process difficult. In fact, one of the demands made by the Wind Energy Business Association is to simplify the procedures to encourage more and more companies to take this initiative.

There are times when, either due to age or an accident such as lightning, some parts such as wind turbine blades cannot be repaired and need to be completely replaced. We are currently working on a number of solutions to recycle the material so that it has the minimum possible environmental impact. For example, one of the preferred techniques is to crush the blades to use the material to make cement.

The first wind blade recycling plant presented in Spain is a project headed by Endesa together with PreZero: A recycling plant that will be located in Cubillos del Sil (León) and included in Endesa's Futur-e Plan for the Compostilla thermal power plant that is currently being dismantled.