Yet, new research in mesoscale atmospheric modeling by UNC Charlotte's Amanda S. Adams and Harvard University's David W. Keith, published Monday in the journal Environmental Research Letters, suggests that the power capacity of large-scale wind farms may have been significantly overestimated.
With large-scale wind farms, as many as hundreds of turbines mounted on tall towers and connected to the electrical grid capture the kinetic energy of the wind. Each wind turbine creates a "wind shadow" behind it, in which the turning blades slow the air. In an effort to reduce the impact of the wind shadows, wind farms space the turbines apart, while still locating as many turbines as they can on the land.
Current estimates of the global wind power resource over land range from 56 to 400 terawatts. Most of these estimates assume implicitly that the turbines extracting the wind energy have little impact on the atmosphere and, therefore, little effect on the energy production.
The new research says that scientists have underestimated the impact that large numbers of wind turbines have on energy production within large farms. Estimates of wind capacity that ignore the effect of wind turbine drag on local winds have assumed that wind power production of 2 and 4 watts per square meter could be sustained over large areas.
The new modeling results suggest that the generating capacity is more likely limited to about 1 watt per square meter at wind farms that are larger than 100 square kilometers.
"It's easy to mistake the term renewable with the term unlimited when discussing energy," Adams said. "Just because you can keep generating new energy from a source does not mean you can generate energy in an unlimited amount."
The research suggests the potential for wind energy could be significantly less than previously thought.
"It's important to take into account all factors impacting the wind energy, so we can assess the capacity of this critical power resource," Adams said. "One of the inherent challenges is how harvesting the resource changes it, making it difficult to accurately calculate how much energy can be produced. The modeling we have done provides information that can help in the understanding of our ability to count on renewable energy sources."
The research also considers the impact of wind energy production on temperatures and by extension possibly climate. Wind farms change the natural wind shear and produce various scales of turbulence. Higher potential temperatures are mixed downward due to this turbulence and result in low level warming, the research indicates.
"Our research suggests that how densely the turbines are placed affects not only energy production but also environmental impacts," Adams said. "We see this impact on average temperatures not only at large-scale farms, but also in small-density wind farms. Some things to consider are the magnitude of temperature changes and also the size of the area affected. We think these findings indicate that additional research is needed in these areas."
The Natural Sciences and Engineering Research Council of Canada funded the research.
Adams' primary research interests focus on mesoscale phenomena, processes, and modeling with an emphasis on phenomena that involve boundary layer processes and/or topographic influences. In recent years, she and her research group at UNC Charlotte have focused on the link between small-scale processes and climate, particularly at the atmosphere and earth surface interface. Her research group concentrates primarily on question at the interface between energy, weather and climate.Current questions her group is addressing include: How will large scale wind energy development impact the Great Plains low level jet? What are the meteorological conditions that lead to wind turbine icing? How does temperature variability in urban areas impact electricity demand? Can we quantify the risks of off shore wind turbines to hurricanes? The energy-related research that Adams' group is conducting includes collaborations with San Diego Gas & Electric, Xcel Energy, and the Weather Underground.
Buffie Stephens | EurekAlert!
Nano-scale process may speed arrival of cheaper hi-tech products
09.11.2018 | University of Edinburgh
Nuclear fusion: wrestling with burning questions on the control of 'burning plasmas'
25.10.2018 | Lehigh University
Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.
Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
20.11.2018 | Life Sciences
20.11.2018 | Life Sciences
20.11.2018 | Physics and Astronomy