Category: Trenches, Medium Voltage and optical fiber cables

  • Medium voltage power cables in wind farms: an introduction

    This post is an extension of the previous short article I wrote some years ago on the characteristics of wind farms medium voltage system. I wrote it with the help of my friend and colleague Kamran, who spent more than an hour answering my questions on the subject. Thank you Kamran! The medium voltage network…

  • Slingers & trenching machines in wind farms: a guest post by Christopher James

    After posting this article on Slingers I have been contacted by Christopher James, an expert on the topic with an exceptional amount of real world experience. He has been so kind to share is knowledge on the theme and I am thankful for that. I am sharing it with you in the very comprehensive post below…

  • Rock slingers for a quicker trench sanding & backfill

    Rock slingers for a quicker trench sanding & backfill

    This morning I found by chance this very interesting website (well, it is interesting if you like wind farm constructions…). Basically it is an Australian company using “rock slingers” (that is, conveyors belts connected to a dumper) to backfill trenches mounted on small vehicles (2.5 meters wide). The equipment is made by CAS, an American…

  • Wind farm earthing and optical fiber cables

    In this post of many, many years ago I explained how wind farm trenches are usually built. In addition to the medium voltage cables, in the trenches usually there are also 2 other type of cables: Earthing cables Optical fiber cables The earthing cables are usually made of copper and they are used to dissipate…

  • Constraints to medium voltage power cables in wind farms

    (This post has been updated in July 2020 with the help of my friend and colleague Kamran) I already discussed in two other posts how the wind farm cable trenches are usually built and how the medium voltage cables are made. However, a more comprehensive explanation should include on how the medium voltage cables are dimensioned. The power produced…

  • Trenchers in a wind farm: do they make sense?

    In a nutshell, the answer is yes – at least if you are able to find one nearby at a reasonable price. In general, you will have several alternatives to dig your cable trenches: Backhoe Backhoe with hydraulic breaker hammer Explosives Trencher The smarter choice will depend on the hardness of the rock. In general, the…

  • Horizontal directional drilling (HDD) in wind farms

    Horizontal directional drilling is a technique frequently used in wind farms when we have the need to cross the pipes below roads, rivers or even the sea. Here you have the picture of 2 slightly different solutions, one using directional drilling and the other with horizontal drilling. The installation of a pipe using directional drilling…

  • Cable trenches layout design

    We try to design cable trenches as straight as possible, avoiding pronounced angles. There are several national norms on the minimum bending angle, for instance UNE 20435/2 in Spain. For environmental and technical reasons we try to design the trench parallel to the access road. When we have to cross an obstacle such as an…

  • Medium Voltage Cables Optimization

    The optimum design of the medium voltage (MV) cables consists in finding the best compromise between the initial cost of the cables and the total energy loss of the system. For this reason we design wind farms with a radial network, and section of the cables decreasing from substation to the most faraway point of…

  • Cable trenches – the nervous system of the wind farm

    Cable trenches construction probably doesn’t looks like the most exciting things in life, but including for them there are things that is better to know to avoid mistakes. They are used to connect the WTGs together with medium voltage cables, and they bring the earth and the optical fibres cables as well. The standard construction…