Wind Turbines Cost

Wind Turbines Cost

Read the following article, which provides detailed information about the expenses incurred, while setting up a wind turbine.
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 for alternative sources of energy, man is reusing an old method of tapping wind energy to produce electricity. Wind turbines are being constructed, and wind farms are being developed to harvest energy all over the globe. The cost of construction of such machines varies according to their types and the scale on which they are being built. These devices have two basic designs, each with its own pros and cons. The first and the most commonly used type/design is the horizontal axis wind turbine or HAWT, which has a tower and blades that turn to generate electricity. The second and lesser known 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. Cost of the turbines varies according to their designs.

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 exists because of the friction and loss of energy due to heat. Thus, a 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, in 1919, and is known as Betz's law. 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 such devices are:
  • Wind Speed: These machines 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 temperatures can affect the running of a wind turbine. Although, this issue is being addressed with improved designs, alterations in temperature still cause changes in energy conversion efficiency in windmills.
  • Loss of Energy: There is a loss of energy due to friction and resistance. Though work is being done to improve designs to reduce and limit this loss, it still does persist. Even the best designs of such machines can harness only up to 70 - 80% of kinetic energy.
Cost of Building Wind Turbines
The expense varies according to the type and size of the turbine that is being built. It could be a large, medium, or a 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 the machines has to be larger to be productive. The common ones used nowadays are about 2 MW in size, and larger ones are also available. The cost of installing a 2 MW machine could range anywhere between 1 - 3 USD million. The expenses are so high because of the many factors involved in installing the machines, which include cost of construction, transportation, 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 building site, to measure the wind power and its variation in speed. The turbine design can greatly affect its efficiency. 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 are cheaper to construct, and do not need unidirectional or constant wind speed, but may not give good energy returns on a large-scale basis.

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 these machines.