April 2013 - Wind farms constructionWind farms construction

I’ve recently discovered the existence of precast foundation for wind turbines. Strangely enough, this solution isn’t having a big success, at least as far as I know.

By the way, there are several clear advantages: first of all, an important time saving.

According to the developer brochure, only 2 days are needed to complete the foundation: the first to install the pieces and the second to connect the tower tensioning the bolts.

Then, as with all serial products, there is the advantage of tighter controls on the quality of the materials and the production

The manufacturer also suggest that the excavation volume is reduced, although I don’t understand why (in the end, it is still a gravity foundation, so the dimensions should be similar).

I also don’t see what happen with the conjunction element (embedded ring or anchor cage in the newer models): I suppose that it will be substituted by bolts enclosed in the precast modules, but I can’t visualize how it will work without the lower flange.

I don’t know how many companies are actives in this business: the picture below are taken from a presentation of Artepref, a Spanish company specialized in precast components.

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.