Offshore wind turbines could weaken hurricanes, reduce storm surge
Wind turbines placed in the ocean to generate electricity may have another major benefit: weakening hurricanes before the storms make landfall.
New research shows that an offshore wind farm could have weakened Hurricane Sandy, shown here on Oct. 28, 2012.
Credit: NASA Earth Observatory image by Jesse Allen, using Suomi NPP VIIRS data provided by Cooperative Institute for Meteorological Satellite Studies (CIMSS).
New research by the University of Delaware and Stanford University shows that an army of offshore wind turbines could reduce hurricanes' wind speeds, wave heights and flood-causing storm surge. The findings, published online this week in Nature Climate Change, demonstrate for the first time that wind turbines can buffer damage to coastal cities during hurricanes. "The little turbines can fight back the beast," said study co-author Cristina Archer, associate professor in the University of Delaware's College of Earth, Ocean, and Environment.
Archer and Stanford's Mark Jacobson previously calculated the global potential for wind power, taking into account that as turbines are generating electricity, they are also siphoning off some energy from the atmosphere. They found that there is more than enough wind to support worldwide energy demands with a negligible effect on the overall climate.
In the new study, the researchers took a closer look at how the turbines' wind extraction might affect hurricanes. Unlike normal weather patterns that make up global climate over the long term, hurricanes are unusual, isolated events that behave very differently. Thus, the authors hypothesized that a hurricane might be more affected by wind turbines than are normal winds.
"Hurricanes are a different animal," Archer said.
Using their sophisticated climate-weather model, the researchers simulated hurricanes Katrina, Isaac and Sandy to examine what would happen if large wind farms, with tens of thousands of turbines, had been in the storms' paths.
They found that, as the hurricane approached, the wind farm would remove energy from the storm's edge and slow down the fast-moving winds. The lower wind speeds at the hurricane's perimeter would gradually trickle inwards toward the eye of the storm. "There is a feedback into the hurricane that is really fascinating to examine," said Archer, an expert in both meteorology and engineering.
The highest reductions in wind speed were by up to 87 mph for Hurricane Sandy and 92 mph for Hurricane Katrina.
According to the computer model, the reduced winds would in turn lower the height of ocean waves, reducing the winds that push water toward the coast as storm surge. The wind farm decreased storm surge — a key cause of hurricane flooding — by up to 34 percent for Hurricane Sandy and 79 percent for Hurricane Katrina.
While the wind farms would not completely dissipate a hurricane, the milder winds would also prevent the turbines from being damaged. Turbines are designed to keep spinning up to a certain wind speed, above which the blades lock and feather into a protective position. The study showed that wind farms would slow wind speeds so that they would not reach that threshold.
The study suggests that offshore wind farms would serve two important purposes: prevent significant damage to cities during hurricanes and produce clean energy year-round in normal conditions as well as hurricane-like conditions. This makes offshore wind farms an alterative protective measure to seawalls, which only serve one purpose and do not generate energy.
Jacobson and study co-author Willett Kempton, professor in UD's College of Earth, Ocean and Environment, weighed the costs and benefits of offshore wind farms as storm protection.
The net cost of offshore wind farms was found to be less than the net cost of generating electricity with fossil fuels. The calculations take into account savings from avoiding costs related to health issues, climate change and hurricane damage, and assume a mature offshore wind industry. In initial costs, it would be less expensive to build seawalls, but those would not reduce wind damage, would not produce electricity and would not avoid those other costs — thus the net cost of offshore wind would be less.
The study used very large wind farms, with tens of thousands of turbines, much larger than commercial wind farms today. However, sensitivity tests suggested benefits even for smaller numbers of turbines.
"This is a paradigm shift," Kempton said. "We always think about hurricanes and wind turbines as incompatible. But we find that in large arrays, wind turbines have some ability to protect both themselves and coastal communities, from the strongest winds."
"This is a totally different way to think about the interaction of the atmosphere and wind turbines," Archer said. "We could actually take advantage of these interactions to protect coastal communities."
The paper, titled "Taming Hurricanes with Arrays of Offshore Wind Turbines," appears online on Feb. 26 in Nature Climate Change and will be published in print in March.
Andrea Boyle Tippett | EurekAlert!
Climate satellite: Tracking methane with robust laser technology
22.06.2017 | Fraunhofer-Gesellschaft
How reliable are shells as climate archives?
21.06.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.
New Manufacturing Technologies for New Products
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
22.06.2017 | Medical Engineering
22.06.2017 | Life Sciences
22.06.2017 | Life Sciences