Author: Francesco Miceli
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The gentle art of EPC wind farms: design responsibility
In the ideal FIDIC world there is little space for the discussion about design responsibility. Either the Employer (FIDIC Red) or the Contractor (FIDIC yellow & silver) is going to do all (or almost all) the design. Unsurprisingly, real life is more complicate than this. You will have an hard time trying to get reasonable…
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Gearbox in wind turbines
Why do you need a gearbox in a wind turbine? The short answer is that you don’t need one – if you are using a direct drive WTG. But even if the solution without gearbox is used by several manufacturers (e.g. the Goldwind 2.5 PMDD, Enercon models, etc.) the majority of makers decided to include…
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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…
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Wind derivatives: is hedging the risk the next step for wind energy?
Weather derivatives are not a new product. The first contract were traded over the counter in the ‘90s, with the Chicago Mercantile Exchange (CME) introducing from 1999 a broad set of products like futures and options that are widely traded today. They are a financial product that can help hedging the risk associated with the…
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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…
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How to measure wind resource
I have to start with a disclaimer – I’m not a specialist in wind resource analysis. However, through the year I’ve seen several time this process so I think I can summarize it with a reasonable level of accuracy (and obviously if you spot a mistake, please let me know). The wind resource assessment is…
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Wind sector management – how to put more wind turbines in the same area
In many project my colleagues from the wind and site department (the people who calculate the best wind turbine model and the optimal layout in a wind farm) are forced to put quite a lot of wind turbines in a reduced space. Each of these wind turbines generate a “wake effect” – basically, they create…
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Dynamic loads on wind turbines
I discussed in another post the relevance of resonance analysis in the design of steel tower for wind turbines and the different technical solutions currently in the market. But what are the loads that could induce resonance in the wind turbine? There are several different type of dynamic loads: Unbalanced rotor. This basically means that…
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What is wind turbine certification?
Wind turbine type certification is the accreditation, done by a reputable third party (“Certification Body”), that a manufacturer is selling a wind turbine that meet relevant standards and codes. TUV, DNV-GL, Bureau Veritas (among others) are examples of Certification Body. The scope of certification, according to the industry standard IEC 61400-22, can be: Prototype certification:…
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Wind farms: top 5 of myths & urban legends
A curious consequence of writing a blog about wind farms is that every now and then I’m contacted by someone hating wind energy. In the majority of the cases, the writer also ask for help to stop or boycott a wind farm somewhere in the word, apparently ignoring the fact that wind turbines help me…