Following a winter period predominated by road construction and cable laying, the wind farm road network can now fully accommodate construction traffic, much of which is now bounded by underground power and fibre optic cables. During the month of April, the focus has now shifted back to the turbine foundations, starting off in the Southern areas of the site.
On the excavated ground, a blinding layer has been applied to 15 foundations in April. This concrete blinding layer provides a flat, even surface on top of which the foundation will be constructed.
The steel-fixing teams returned to site this month to construct the steel reinforcement. This steel structure sits on top of the blinded layer and provides the concrete foundation with tensile strength which will ultimately support the wind turbine. The steelworks have been completed on seven (7) turbine foundations this month, with work ongoing on a further eight (8).
All foundations at Björkvattnet Wind Farm are gravity foundations. This means that the wind turbine is fixed solely on the weight of itself and the foundation it sits on. The bulk of this weight comes from the concrete. After the steel reinforcement works have been completed, a concrete mix, which is batched on-site, is then poured into the foundation pit. This mix fills the space between the steel reinforcement. Concrete pours have been carried out on two (2) foundations this month. The site now has fourteen (14) turbine foundations completed.
The concrete is then covered with the excavated earth and stone, which performs three functions: an aesthetic one by hiding concrete base, an environmental one by allowing further soil regeneration, and a practical function by adding extra weight to the foundation.
About 45% of the cable laying works have been completed at the site. These cables are laid in the trenches running, for the most part, along the side of the site tracks. These cables connect the wind turbines to the on-site substation for energy distribution, and fibre optic carry operational data to the operations building.
Works are progressing well at the substation building, with concrete poured into both transformer foundations. These foundations will support the transformers, which will increase the voltage of the power coming from the wind turbines to allow for efficient distribution to the grid network.