Thousands of wind turbines are nearing the end of their useful life, the big question is what we will do with their blades afterwards
After many years in which fossil fuels have dominated a large part of the electricity generation mix, today renewable energies have positioned themselves as the cleanest alternative for generating electricity. However, it is important to remember that there is absolutely no form of electricity generation that has zero environmental impact.
Although a priori it is less, renewable energies also have an impact on the environment. However, unlike other energy sources such as fossil fuels where the environmental impact occurs mainly during the useful life of the plant (emissions of greenhouse gases and other pollutants), most of the environmental impact of renewables is concentrated in two moments: manufacturing and dismantling. And it is that when a renewable installation stops working, it becomes a pile of scrap that must be reused or, failing that, recycled.
The management of this waste is a particularly sensitive issue in the renewable industry. At the end of the day, renewable energies must be consistent with their final objective, which is none other than reducing the environmental impact of electricity generation. It is not acceptable to sell a speech on sustainability and care for the environment and then treat the waste from the facilities in any way.
The reality is that little by little we are approaching a future where waste from hundreds of renewable facilities will have to be managed that will be unusable once the end of their useful life has been reached.
Wind turbines are getting old
The problem of waste management from the renewable industry has become very sensitive in recent times, especially in the case of wind power, after Bloomberg published some shocking photos of a landfill full of wind turbine blades in United States. And it is that this component, due to its manufacturing materials, is the most difficult to manage in the case of wind turbines.
The design life of a wind turbine is 20 or 25 years depending on the location, although it is common practice for it to last up to 30 years by making some investments (replacement of some components, etc.). Taking into account that modern wind energy is a technology that has been with us for more than 20 years, the conclusion is clear: a part of the world’s wind farms is approaching the end of their useful life and with it, their decommissioning. In a few years we will find hundreds of useless wind turbines, whose components will need to be managed.
To get an idea of the magnitude of the problem, let’s make some numbers with the figures for Spain, the fifth country in the world with the most installed wind power after China, the United States, Germany and India.
In total, according to data from AEE (Wind Business Association) in our country there are 1,265 wind farms installed in more than 1,000 municipalities, with more than 21,419 wind turbines, which gives a total of 64,257 blades (three per wind turbine). Of course, these figures continue to grow after the sector has started up again and with the forecast that it will reach 50 GW in 2030. Of course, it does so with increasingly larger models.
Regarding the age of the wind turbines, according to PREPA data, of the more than 27,000 MW of wind power that Spain has, around 11,000 MW are more than 15 years old, while some 3,500 MW are older than 20 years.
Blades, the great problem of wind turbine recycling
In general terms, most of the components of a wind turbine are recyclable. Currently around 85-90% of the materials in a wind turbine can be recycled. They are made primarily from just six basic raw materials: steel, cast iron, fiberglass (and similar composites), copper, aluminum, and the concrete used in foundations.
While most materials are commonly managed in other sectors, the challenge for the wind industry is centered on the recycling of blades. While the rest of raw materials have an established recycling chain, the blades are made of composite materials (fundamentally, fiberglass, carbon fiber and resins), especially difficult and expensive to separate for proper recycling.
Nor is it that the composite materials used in the blades are an exclusive problem of the wind industry, but rather that it is a problem shared with other industrial sectors who also use them. In any case, it is important to know that shovels are considered non-hazardous waste according to Spanish legislation.
The truth is that the challenge facing the sector is not small. According to data from WindEurope, the European wind power association, around 14,000 blades could be dismantled during the next 5 years in the old continent, which is equivalent to between 40,000 and 60,000 tons of waste of these compounds.
Finding a way to properly reuse or recycle these blades is a priority for the industry.
Shovel recycling, what options are there?
There are three main ways to manage wind turbine blades once they reach the end of their useful life: reuse, recycling and storage.
The reason a wind turbine is decommissioned is not always the end of its useful life. Sometimes it occurs due to strictly financial decisions, since it may happen that larger and more modern wind turbines are installed in the same location It might be a better business than keeping the old ones going.
This means that not all dismantled wind turbines have to be disposed of, yes or yes, but they can honor the first of the three erres: be reused and installed elsewhere. However, it is important to note that this is not always possible or easy, since electrical regulations evolve and old wind turbines often do not meet the requirements of the countries.
In cases where reinstallation is not possible but your components are still in good condition, these may be used as spare parts for other wind turbines similar that are still in operation. In this way, you avoid having to manufacture new parts that in most cases are no longer serialized (because that model of wind turbine is no longer marketed).
Finally, there is the option of its reuse in other applications beyond wind energy, mainly architectural. Among the most remarkable and curious, is this bicycle parking installed in Denmark or a planned bridge in the city of Aalborg.
Once reuse is ruled out (which, unfortunately, is not always possible), we move on to the next step, recycling: recovering the raw materials to be used in another application. Among the main forms of recycling are the following:
- Mechanical recycling: consists of crushing and / or separating the material for later reuse in the manufacture of other fibrous materials or as filling material (insulation or concrete filling, for example). In Spain, the Reciclalia company specializes in this type of recycling.
- Thermal recycling: As with many other wastes, wind turbine blades can be incinerated to generate energy. Another option is pyrolysis and gasification, by which fibrous materials can be preserved for use in secondary applications. In contrast, there are the emissions associated with these processes.
- Chemical recycling: processes such as solvolysis, which involve the use of solvents and thermal processes to separate the resin from the fibers. Afterwards, both can be reused.
As we have discussed previously, composite materials they are not hazardous waste, so they can be stored in landfills without generating problems in the environment (beyond the occupation of the land itself and being a waste that will be there “forever”, which is not little).
In general terms, we can say that recycling technologies to treat waste from wind turbine blades are now available. However, business opportunities are still lacking due to reasons such as economy of scale (there is still not enough volume of waste to make a profitable business) and the cost of transportation from parks to recycling centers, among others. In addition, the alternative of storing it in landfills is generally cheaper than any other, which encourages its use.
Some countries are already getting ahead of the problem. For example, Austria, Germany, the Netherlands, and Finland prohibit composites from being landfilled or incinerated. France, for its part, is considering introducing a recycling target for wind turbines in its legislation.
At the European level, there is the European FiberEUse project in which Spanish companies such as Tecnalia, Siemens Gamesa or Maier participate, and which focuses on the large-scale demonstration of new circular economy value chains based on the reuse of fiber-reinforced composite materials at the end of its useful life. The DecomBlades consortium, made up of ten partners who have received funding from the Danish Innovation Fund, has also recently been presented. The project aims to lay the foundations for the commercialization of sustainable techniques for the recycling of wind turbine blades.
In short, and despite the fact that it is still not barely visible, the electricity sector faces a challenge of great magnitude with the management of hundreds of wind turbine blades. Clear legislation and encourage the recycling of these materials (or discourage its storage in landfills) is necessary to make wind energy 100% sustainable.
Images | Pixabay, Google maps
Graphics | AEE, ETIPWind