Typical wisdom says that we have already reached the maximum efficiency per wind turbine. However, this restriction on wind energy efficiency might be based on the use of mature technology without re-invention. The California Institute of Technology research has re-invented some of the basic assumption that underlines the wind industry. They believe it is time to change the 30 years old designed used in conventional wind farms. A new concept where wind turbines can be constructed closer (more compact) would significantly increase the energy efficiency of a farm per its footprint.
Their concept over-rides previous assumption that the only way to increase efficiency of wind turbines is to go offshore and to build larger turbines.
John Dabiri, a professor of Engineering & applied Science as well as the director of the Center of bioinspired Engineering at Caltech, says that wind farms are not really that efficient. The conventional wind turbines occupy a large footprint, and much of the wind is untapped. The modern wind turbines are larger and taller, meaning that they do catch higher winds.
Nevertheless, the increase in size and height of wind turbines, leads to higher cost in terms of construction, engineering, maintenance and other environmental and landscaping costs.
In the Journal of Renewables & Sustainable Energy issued by the American Institute of Physics’ Dabiri gives a description on how to improve the efficiency of wind farm designs.
It is certain that the wind that can be harnessed at 30 feet is extremely much more efficient and constant than near the ground winds. Yet, if the low-winds were captured in an efficient way, then it would be no need to go for the higher altitude winds. Research has shown that capturing the wind that exceeds 30 feet can power several times the whole world energy demand.
The use of vertical-axis wind-turbines (VAWTs) settings proposed by Caltech will make it possible to establish wind turbines close to each other. This would avoid the drawback of large spacing between the horizontal-axis propeller-wind turbines.
Dabiri says that VAWT generate a series of benefits. The design is highly efficient and provides a low-cost way to capture near ground winds. In addition, it would decrease the level of negative environmental consequences generated by wind turbines such as damaging landscape views.
However, VAWT structures used today are less efficient and are commonly at risk of structural failures. However, improvement in materials used and aerodynamic loads can prevent these fatigue failures associated with VAWT.
According to recent studies, VAWT turbines are evolving in the right direction, and a pilot study suggests that off-the-shelf wind turbines are becoming more efficient.
The aim of the research is to find ways to make wind energy even more efficient. Dabiri says that the use of smaller power generation approaches to harnessed wind energy will be significantly cheaper as less expensive material will be used.
Soon a re-invented approach of harnessing wind energy might be used.
Source: Science Daily