Dow Company and their links with the Wind Industry.

July 26, 2010

It is interesting to discover how companies that they are not directly related to the Wind Power can work for this field as the typical companies do. An example of this, it is the American Chemical company Dow Chemical. This multinational, it is one of the largest companies on the Chemical field with DuPont or BASF.

Dow Chemical provides a wide range of plastics, chemicals and agricultural products with presence in more than 175 countries and employing more than 50.000 people worldwide. In the last year (2009), it reached 44.875 billion U.S dollars and 648 billion U.S. dollars.

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Politics and Cap&Trade.

July 17, 2010

I have just found an article on Renewable Energy Focus website that explains which countries are interested on increase the target to reduce the greenhouses reduction for 2020. On one hand, we have countries (Spain, Germany, Sweden) which want to achieve the target of reduction to 30% below 1990 emissions. Others, like the UK, Portugal, Austria or France that want to keep the 20% approved in the past years. And finally, countries such as Italy, Denmark, and Belgium which their interests are different and they want to reduce that demanding target.

The position of each country must be directly related to the “Cap and Trade” regulatory system. This program allows to the manufacturers of gases linked to global warning to “trade” pollution permits, or allowances among themselves. It is important to point out that the European Union Emission Trading System is currently the largest functioning Cap and Trade system for greenhouse gases in the world (the permits generate an industry of $140 billion per year).

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Opponents to Wind Farms.

July 16, 2010

In preview posts, we described some benefits about the Wind Power. We usually hear wind power is a renewable, clean and a safe energy source. However, this kind of power has got disadvantages as well. Noise, visual impact, weather changes, birds mortality are just examples. This video is the trailer of a documentary film that shows us those problems. Spectacular and painful the image of a vulture bird brought down by a wind turbine blade.

The video is just one piece of the work from associations, organizations and people who think wind farms bring more problems than advantages. Maybe, the most famous organization is Country Guardian created in 1991 in the UK and although they are not opposed to wind energy as such, they condemn the abusive construction of wind farms nearby population centres and natural landscapes. It is not the only, they are more in Europe and America.

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Adopt a Wind Turbine.

July 13, 2010

The EWEA (European Wind Energy Association) started a campaign to promote the wind energy, called Fresh Air. On this website is possible to choose an installed European wind turbine and “adopt” it. It is FREE cost, and the goal is to make people more conscious on Wind Power’s benefits. You can adopt just one wind turbine for each email, so I suggest you to be sure which one you select. Are you interested to adopt a wind turbine? What are you waiting for?

According to this campaign, the video show us interesting facts on Wind Power sector and the potential of wind energy to satisfy the energy market demand without CO2 emissions. Today, Wind Power represents the 4% in the EU electricity, and in 2030 it is expected to increase that proportion to 35%. Strategic investment for a continent as Europe which is so shortfall of conventional energy resources.

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Power Quality Standards.

July 13, 2010

Voltage provided by Wind turbines must comply some requirements specified in the IEC 61400-21 standard. Here we are some power quality parameters that power energy from wind turbines must be under control:

Rated Data

  • Rated Power (Pn) (or Active Power): Maximum continuous electric output power for a wind turbine under operating conditions.
  • Rated Reactive Power (Q­­­­­n): Reactive power under rated power, nominal voltage and frequency.
  • Rate Apparent Power (Sn): Apparent power from the wind turbine while operating at rated power and nominal voltage and frequency.
  • Rated Current (In): Current from the wind turbine while operating at rated power and nominal voltage a frequency.

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Brake Systems in Wind Turbines

July 12, 2010


According to quality parameters, DS472 (Danish Standard) and GL rules, wind turbines must have two independent braking systems. However, the IEC 61400-1 requirement does not specify what kind of two braking systems must have, but requires the protection system to remain effective even after the failure of any non-safe-life protection system component.

Usually, it makes sense to supply both aerodynamic and mechanical braking. Aerodynamic brake is more benign than mechanical braking, so it is always used in normal shut-downs. On the other side, although a braking system must be used during shut-downs, sometimes technicians allow rotor free turns (idle) within low winds. This strategy reduces the frequency of imposition of braking loads on the gear train.

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Power Electronic Concepts in Wind Turbines.

July 10, 2010

In recently years, we have lived big discoveries on the Power Electronic field that unveil new opportunities to improve the performance in the electric circuits and therefore, in Wind Power industry. Power Electronic can be defined as the brand of the electrical engineering which studies the control and conversion of electric power. Therefore, the power conversion systems can be classified according to the type of the imput and output power:

Here we are the basic components in the Wind Power industry.

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Generators in Wind Turbines.

July 9, 2010

Basically, any type of three-phase generator could work in a wind turbine but they must fulfill some requirements. We have just classified them according to their generator type and the coming prototypes that nowadays we are studying. This post, as the last one, is a summary from the book Wind Power in Power Systems (Chapter 4) by Thomas Ackermann. However, for any further information, this link can be interesting.

Asynchronous (Induction) Generator.

It is the most numerous in wind turbines. Advantages: Robustness, mechanical simplicity, low price. Disadvantages: It has to receive an exciting current from another source and consumes reactive power (so, reactive power is supplied by the grid or by a power electronic system).

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Types of Commercial Wind Turbines.

July 8, 2010


We already saw the different wind turbines we can find nowadays, from the HAWT to VAWT. However, the most commercial at this moment are the High Tip Speed Ratio HAWT. In this post, we are going to describe the different models of wind turbines and what kind of technology they use to convert the mechanical energy to electric energy.

If we pay attention at the above table, we can see there are two wind turbines models according to their Speed Control and Power Control. Thereby, we can find four models: Type A, Type B, Type C, and Type D (see the below diagram). There are three variants for the Type A (A1,A2 and A3). Although it would be possible to manufacture the same variations for the B, C and D Types, it would be not worthy (from the commercial point of view) because these models lack the capability for a fast reduction of power (see the grey-colored boxes in the first diagram). Let´s start describing the possibilities to control the power the aerodynamic forces on the turbine rotor.

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What’s inside a wind turbine?

July 7, 2010

This video posted on Youtube.com has sparked my attention. Firstly, because there are not so many videos like this that explains the main parts of a wind turbine, and second because it is worthy and is well-structured. The video is made by UVSAR, a British company which provides technical services for all those involve in work at height.

The video shows us the layout of two typical wind turbine generators, from the transformer at the floor level, ladders (or elevators), to the electrical cables attached to the walls of the tower.

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