Wind Turbines Cost

Wind energy has been in use for quite a long time now, with windmills being used effectively to do mechanical work. With the growing need nowadays for alternative sources of energy, man is reusing an old method of tapping wind energy to help produce electricity. Wind turbines are being constructed and wind farms are being developed to harvest wind energy all over the globe. The cost of construction of wind turbines varies according to their types and the scale on which they are being built. Wind turbines have two basic designs, each with its own pros and cons. The first type of wind turbine design is the horizontal axis wind turbine or HAWT, which is the most commonly used type of turbine, with a tower and blades which turn to generate electricity. The other lesser known wind turbine design is the vertical axis wind turbine or VAWT, where the rotor is arranged in a vertical direction, and is not pointed towards the direction of the wind. Wind turbines cost varies according to their design as well. In the following paragraphs you will find out whether wind turbines are cost-effective in proportion to their efficiency.

Cost and Efficiency of Wind Turbines

Efficiency of Wind Turbines
Are wind turbines competent tools of harnessing energy? As with all machines and energy conversion tools, there is some loss of energy in the windmills and it does not convert all the wind energy to electrical energy. This is due to friction and loss of energy due to heat. Thus, a wind turbine can convert a maximum of about 59% of the wind energy to electrical energy. This was determined by a German physicist named Albert Betz, way back in 1919, and is known as Betz's law. Could this percentage of energy transforming efficiency be enough for completely fulfilling our energy requirements? Though it does seem like an insufficient percentage of energy production, wind turbines can give decent energy returns. Some of the factors that can affect the efficiency of a wind turbine are:

• Wind Speed: Wind turbines are usually designed to run at a specific wind speed and any variation in wind velocity can lower their efficiency.
• Temperature Changes: Extreme change in temperature can affect the running of a wind turbine. Although this issue is being addressed with improved designs nowadays, alterations in temperature still cause changes in energy conversion efficiency in windmills.
• Loss of Energy: As in any machine there is a loss of energy, due to friction and resistance. Though work is being done to improve turbine designs to reduce and limit this energy loss, fact is that it still does persist. Even the best designs in wind turbines can help harness only up to 70-80% kinetic energy.

Cost of Building Wind Turbines
The cost of building a wind turbine varies according to the type and size of the wind turbine you are building. It could a large, medium or small one. Installing a wind generator at home can cost you up to 4000 dollars. However, making a simple homemade wind generator will cost you much lesser and if you can afford it, you can then try to scale it up to a bigger size. For commercial purposes though the scale of wind turbines has to be larger to be productive. Common turbines used nowadays are about 2 MW in size, bigger ones are also available. The cost of installing a 2 MW could range from anywhere 1-3 million US dollars. The costs are so high because of the many factors involved in installing the turbine. They include cost of construction, transport costs, setting up transformers, location costs and maintenance. Cost efficiency can greatly depend on the type of turbine, its location and design. Also an extensive study on the feasibility of the project has to be carried out at the location to measure the wind power and speed along with its variation in speed. Wind turbine design can greatly affect the efficiency of a turbine. HAWT or horizontal axis wind turbines give better energy returns only at areas with high and fairly constant wind speeds and are very expensive to build and transport. VAWTs on the other hand, are cheaper to construct and do not need unidirectional or constant wind speed, but may not give good energy returns on a large-scale.

So, are wind turbines cost-effective? They are if all the pros and cons are kept in mind. Although wind turbines cost a lot of money to construct, they can be used as a part of alternative energy harnessing strategies, especially in pragmatic areas feasible for the functioning of wind turbines.