Concrete tower assembly in Chile

 

An interesting video on the use of concrete towers in Chile. Among the benefits of this solution the creation of local jobs (several hundred for factory) and the increase of local content (the amount of goods and services provided locally, an important parameter in some tenders).

Concrete towers are especially cost effective when the hub height is over 100 meters. Additionally they are less prone to price variation - steel prices, at least in Europe, dropped in 2016 to rebound in 2018.

Finally transport cost are usually lower, at least if the factory is located near the wind farm as it is usual.

Wind turbine controlled demolition

A reader of the blog shared the link of this video, showing the controlled demolition of a wind turbine in the UK.

The turbine looks like an old Acciona Windpower model. As you will see, the turbine is connected using a rope to a back hoe and the base of the tower is slowly cut using a blowtorch.

Then the backhoe start pulling, and the turbine fell to the ground pretty much like a tree.

I am aware that this solution has been used in several wind farms in different countries. However, I believe that this method is questionable. I have two concerns:

  • Environmental impact. Not only the turbine destroy a bunch of trees but above all after the impact with the ground the debris flight everywhere. I assume that the area can be cleaned afterwards – however filling the area with fragments of different materials looks like a suboptimal solution to me.
  • Safety risks. You will notice that at the minute 3:00 one of the blades hit the ground and detach itself from the rest of the turbine, moving in the direction of the backhoe. An objection can be that the rope can be long enough – however giving the geometry of the turbine and its different materials, I still see the residual risk of flying fragment hitting the operators.

I would recommend the “component by component” dismantling. We used this solution in a wind farm in Portugal and I believe it is much safer.

To see an intermediate solution (partial dismantling and partial demolition), have a look at this other video.

It is the repowering of El Cabrito, a very old wind farm near Tarifa (south of Spain). By coincidence, that area is also one of my preferred holyday destination, so I have several pictures of the old turbines.

You will see how the crane dismantle the blades and the nacelle. Subsequently, a different tool is used to crash the tower.

What happen to decommissioned wind turbines?

In a previous post I mentioned my experience with a repowering (a wind farm where the old turbines are exchanged with new models to increase the production and lower the maintenance costs).

But what happen with the old turbines when they are dismantled?

For some of them there might be a new life. There is a market for second hand turbines – some years ago I met one guy who purchased a bunch of old WTGs (I believe they were in the 200 KW range) and made his own wind farm with a very reasonable investment.

However the majority of decommissioned turbines are scrapped. This bring some challenges because not all components are so easy to recycle.

In order of complexity I would say that the least problematic element is the tower – it’s usually made of steel and it can be easily sold at the current market price.

The foundation is another element that can be left untouched below ground or demolished. The resulting material can be used again in construction, for instance in a road embankment, sub base or even as aggregate in new concrete elements.

I’ve also seen a very interesting technical solution where the old foundation becomes part of the new one – in this case you will need to have both the new and existing turbine at the same coordinates.

The nacelle has several different elements, including some that are potentially contaminating (e.g. the oil of the gear box). More complex to recycle but still doable.

By far the most challenging components are the blades. Usually they are made of composite materials – steel and glass or carbon fibers reinforcement in a polymer matrix. Usually this matrix is thermoset, meaning that the polymers are cross linked (that is, it will be very difficult to separate the elements).

The difficulty start from the logistic. Blades are very long elements: the old are around 20 meters, but recent models are already above 50 meters and they need special trucks to be moved. Theoretically you could chop them into pieces before transportation but the tools could not be easily available, and I also see some safety risk in cutting blades on site.

The following problem is what to do with them: as mentioned there separating the components is not simple, so today many blades ends in a landfill. Alternative solutions are currently being investigated but it’s still challenging to find a cost effective solution.

There are also alternatives uses: in northern Europe (Netherlands, Denmark, France) there are several architectural projects made using old blades, such as kids playground, bus stops, seats and even bridges.

The new playing filed: multi-brand wind turbines service

Yesterday I had the pleasure to meet my friend J. here in Hamburg.

J. works for V., a very big Danish wind turbine manufacture. Specifically he works in what looks like the new battle field for our industry – multi brand wind turbine operation and maintenance (O&M).

Basically it means that V. is offering not only Service for its own wind turbine models – it’s providing it also for competitors models, like Siemens/Gamesa, GE and the like.

There are several good reasons to do that - for instance:

  • Operational synergies. If you have wind farms already under maintenance in a specific area adding MW under maintenance will have a lower marginal cost.
  • Knowledge of the business already accumulated. iI you have thousands of WTGs under maintenance you should have a very clear idea of what could go wrong next during the life of the turbine. This  also include more in house knowledge to propose to the customer solutions like “fix it, don’t buy a new one”.
  • Scale factor in procurement: cheaper spare parts due to a very robust supply chain.

Additionally, customers could find interesting the “one stop shop” solution – for instance big utilities owning wind farms with several wind turbines brands might like the idea of having a single counterparts taking care of all the portfolio.

What strikes me the most is the possibility to implement technical retrofits solutions such us the vortex generators on competitors' WTG models. This basically means that when a wind turbine manufacturer discover a new technique to get more energy out of a turbine it could be able (in some cases) to apply this solution to the turbines of competitors.

I suspect that the market will probably move to a consolidation in the Service business arena, were several small to medium companies are operating locally

V. gave a clear example of it purchasing 2 O&M companies, UpWind Solutions in the US and Availon in Europe.

I also believe that sooner or later a war on intellectual property infringement will start, as several components are “tailor made” (that is, fabricated for a specific wind turbine manufacturer).

For sure you can reverse engineer them, but build them again could lead to legal problem. The same apply to the software of the WTG: many improvements are due to new algorithms and control system, and if you want to implement them you will probably need to put your hands on the software of the competitors.

There is always a second time: wind farm repowering

At the beginning of the year I’ve had the pleasure to work at my first repowering EPC – Vergao, in Portugal, together with Generg (a big local player).

This is supposed to be one of the many projects that should materialize during the next years. My former manager Luis Miguel thinks that repowering is “the next big thing” in wind energy.

I agree with him that sooner or later it will kick off. In theory, wind turbines are designed for a life of 20-25 years. Through heavy maintenance and substitution of the main components (e.g. gearbox) it can be probably extended a bit more. This practice is called life extension or retrofitting.

However, at the end of the day the question is: does it make sense to keep running old turbines? Or it’s more cost effective to install new WTGs?

Older wind farms are usually in incredibly windy site (class I, according to the IEC classification) and are probably using turbines of less than 1 MW.

Therefore it will be possible to reduce the number of installed turbines (a ratio of 3 old for 1 new would not surprise me) and even so increase the total production.

What can sometime hinder the repowering is not the availability of a better technical solution – and it’s often not even a problem of financing. What can complicate the picture are difficult legal frameworks, low social acceptance, environmental constraints , etc.

In theory, there are scenarios where the best solution will be to dismantle the wind turbines and scrap them (or sell them to third world countries).

Coming back to my personal experience, working at a repowering has been a very interesting professional experience.

There are quite a lot of unusual challenges, as the existing WTGs have to be dismantled while in parallel new ones are erected. This makes the time schedule more complicate than usual, and bring new health and safety challenges due to the many teams working at the same time.

I’ve also had the opportunity to look into new topics, like the possibility to “recycle” the existing foundation incorporating it in the new one (yes, you can do it), the market price of used turbines or the environmental requirements linked to the dismantling and scrapping of wind turbines.

Wind Energy in Finland

One of the things I enjoy more in my job is that it gives me the possibility to work in several  different countries.

In  the last months I've had the pleasure to visit several time Finland for a project developed by Neoen (the French developer that it's about to launch its IPO) and Prokon.

It's a 81 MW project called "Hedet". 18 Nordex/Acciona N149 4.0-4.5 MW turbines will be installed under a full EPC contract in an area near Närpiö (a low - medium wind site in West Finland).

It will be built in 2019, bust some preliminary works for roads and tree cutting have already been started.

The energy will be used to power a Google data center (see my other post on this topic).

It’s interesting to note that this is a private, unsubsidized PPA – meaning that it is a transaction between companies, not a “classic” setup where the electricity is sold by the developer to an utility for public consumption.
I believe that this kind of deal will increase in the next years given the sharp decrease of solar and wind plants.

In addition to Hedet there is a second group of wind farm that will be built in Finland in 2019, a portfolio of 107 MW divided in 4 different projects, all of them with the N149/4.0-4.5 MW.

These project are developed by Ox2 (a big player in Northern Europe) and not EPC (they are "Clean Sell", to use a regrettable expression I've heard to define a Supply and Installation project).

The Ox2 projects are founded by IKEA - now you know were your money end when you buy the "Billy" bookcase (I think I bought like 5 of them when I was young).

Wind energy use is growing in Finland – the country started somehow late (in 2010 they had less than 200 MW installed) to accelerate strongly in the last few years. The country has over 2 GW installed now, covering about 5% of consumption.

I would like to thank our colleagues in Finland and all the subcontractor we’ve worked with in the last months. Thank you for your hospitality!

Raki wind farm, Cile

 

A spectacular video of Raki wind farm, a beautiful project I’ve worked at.

Owned by Rame Energy (formerly Seawind) It is a 15 MW wind farm in the Bio Bio region (more or less in the middle of Chile).

WTGs are 5x V112 3MW turbines, and civil works have been developed by CJR.

The earthworks were not especially complicated, while the geotechnical study for the foundation required a more detailed, in depth study.

Talinay Oriente 90MW EPC Wind Farm

Although I don’t normally post stories about wind farms I’ve worked at I want to do an exception for Talinay, a project with whom I have a relationship almost emotional.

Located in Chile, in the Coquimbo province, near the Limarí river, it has been a project entirely developed by Vestas with internal founds and my first “hands on” EPC experience.

We’ve had the pleasure of optimizing the layout both in the preliminary phase, working together with the wind & site team, and in the constructive project. It was tough, because it is located in a mountainous area where impressive earthworks are needed.

It is a mix of V90 and V100 turbines of the 2MW platform, with an installed capacity of 90 MW.

Connected to the grid in March 2013, it has been constructed at an amazing, “china style” speed: with almost 400 peoples working together on site during the busiest period, it was a record for the foundation (5 per week, with two concrete plants on site working full time day and night) and the turbine installation (4 WTG per week).

The wind farm was completed in 6 months.

Almost all the big players of the sector have been involved: from the engineering side support was provided by IDOM, SISENER and ESTEYCO, while the main subcontractor was GES who worked with local and international subcontractors (among them, Hormigones Melón, Burger Gruas and CJR).

On the electrical side, it was one of the first (or maybe the first) PASS installed in Chile. The transformer was developed at lightning speed (155 days ex works), while the substation was made by ABB and Siemens.

Now is property of the Italian utility ENEL Green Power, who also signed a service agreement. Part of the money of the deal comes from a loan from Denmark’s Export Credit Agency (EKF). ENEL has an aggressive expansive approach in the Chilean market, where is developing several other wind farms (some of them with Vestas).

Below you will find several interesting pictures: two trucks pulling a tower section due to the high slope of the road, PASS switchgear and line trap, concrete plant and other interesting views of the wind farm.