As US’ first offshore wind farm takes root, study indicates wind may be more powerful, turbulent than expected
University of Delaware researchers report in a new study that offshore wind may be more powerful, yet more turbulent than expected in the North Eastern United States.
The findings, published in a paper in theJournal of Geophysical Research: Atmospheres, could have important implications for the future development of offshore wind farms in the U.S., including the assessment of how much wind power can be produced, what type of turbines should be used, how many turbines should be installed and the spacing between each.
The study, led by Cristina Archer at UD and Brian Colle at Stony Brook University, analyzed historical data from 2003-2011 at the Cape Wind tower located near the center of Nantucket Sound off the coast of Martha’s Vineyard, Massachusetts, and collected complementary data at the same location in 2013-2014.
Co-authors on the paper, titled “On the predominance of unstable atmospheric conditions in the marine boundary layer offshore of the U.S. northeastern coast,” include UD professors Dana Veron and Fabrice Veron, and Matthew Sienkiewicz from Stony Brook.
The paper’s main finding is that atmospheric conditions around Cape Wind are predominantly turbulent, or unstable, which is in stark contrast to prevailing data from European offshore wind farms in the Baltic Sea and the North Sea. European studies of offshore wind document that atmospheric conditions there are predominantly neutral– meaning neither too windy nor too still, but somewhere in the middle, with unstable wind conditions occurring only 20 percent of the time.
“By contrast, our study found that wind conditions at Cape Wind are unstable between 40 and 80 percent of the time, depending on season and time of day,” explains Archer, an associate professor in the College of Earth, Ocean, and Environment’s School of Marine Science and Policy and Department of Geography and a governing member of the Center for Carbon-free Power Integration.
Stable, unstable and neutral
Explaining how wind can be stable, unstable or neutral is a tricky business, Archer says. When the atmosphere is stable, winds are smooth and consistent (think of when a pilot tells airline passengers to sit back and enjoy the ride because the weather is clear all the way to their destination).
When the atmosphere is unstable, it is similar to turbulence experienced by airline passengers during a flight — the wind is choppy and causes high winds from above and slow winds from below to crash into each other and mix together, causing a bumpy and unpredictable ride for the air current.
Neutral conditions hover in the middle, with an average amount of turbulence and wind speed variation.
“The advantage of these turbulent conditions is that, at the level of the turbines, these bumps bring high wind down from the upper atmosphere where it is typically windier. This means extra wind power, but that extra power comes at a cost: the cost of more stress on the turbine’s blades,” explains Archer.
An expert in designing offshore wind farms, Archer says the findings may have implication on how future offshore wind farms in the region are designed.
“If you have increased turbulence, you’re going to design a different farm, especially with regard to turbine selection and spacing. And guess what? Even the wind turbine manufacturing standards are based on the assumption of neutral stability,” Archer says.
Is something special going on in the North East?
No measurements exist of wind and turbulence around an offshore wind turbine’s rotor blades in the ocean in the U.S., because until now, none have existed. The first U.S. offshore wind farm is currently under construction at Block Island, off the coast of Rhode Island.
Instead, this type of data has been estimated based on either numerical simulations or using available buoy data to infer what the conditions would be at the height of the wind turbine’s rotor blades. But wind data measurements from 2003-2009 at the Cape Wind Tower, a multi-level tower with sensors positioned approximately 65 feet, 131 feet and 196 feet in height, have shown that the Cape Cod region’s atmospheric conditions are generally unstable. Neutral conditions only occur approximately 20 percent of the time.
In 2013 and 2014, with funding from the U.S. Department of Energy, the UD-led research team launched a campaign they coined IMPOWR, Improving the Modeling and Prediction of Offshore Wind Power Resources, to validate the Cape Wind tower findings with additional measurements.
The IMPOWR researchers flew a plane around Cape Wind 19 times over two summers, above and around the tower, and measured wind, temperature and humidity during various weather conditions. They also installed new wind and wave sensors on the Cape Wind platform.
Combined with buoy data from just above the water’s surface and with the historical data from Cape Wind, the IMPOWR field data painted a surprising and yet consistent picture of the area’s wind resources.
“We get the same message whether we look at the turbulence from the flights or from the sonic anemometers on the tower, or whether we consider the wind speed data alone. The marine atmosphere is more likely to be unstable than neutral. Having three separate pieces of evidence that support the same finding allows us to be confident that there is something special going on,” she says.
Wind direction also plays a role in whether the wind is smooth or turbulent. When the wind comes from the southwest, the data show that wind tends to be more stable and to increase in speed from the bottom to the top of the rotor blades. But when the wind comes from the north, northwest or offshore, it is more likely to be unstable and to have a relatively uniform speed across the turbine rotor, Archer says.
Further study is needed to understand whether this phenomenon is localized in the Cape Cod area, along the East Coast in general, or present throughout the U.S., since other offshore wind installations on the East Coast are planned for Maryland, New Jersey and Massachusetts.
“It’s important to ensure that science doesn’t underestimate the possible wind resources,” Archer says. “Now that we know what is happening in Cape Cod, we have more work to do to determine whether it exists anywhere else or whether it is unique to this region.”
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“Is something special going on in the North East?”
Yes. Assumptions were made and not validated.
Pretty obvious that offshore winds will be stronger. You get Javier Stokes at the surface boundary, voila, turbulence.
Nullschool gives valuable lessons of relative wind strengths ocean vs land:
Why do you re-fill a water pistol when it runs out of water?
Because there is little energy in displaced air, whereas there is useful energy in displaced water.
There is little energy to be harvested from the wind. It is also variable and above all unpredictable. These facts, coupled with the fact that there is presently no practical means of storing energy, would tell any engineer that this is not an energy source capable of powering forward the 21st century. There is a reason why our forefathers abandoned windmills in the 18th and 19th centuries, and sail power in the 19th and 20th century.
The way to the future is not to go backwards to the past.
tell any engineer that this is not an energy source capable of powering forward the 21st century.
engineering is no longer done by engineers, but by politicians accountants and dreamers.
18% of all UK electricity was provided by wind in December 2015…
A valid point Griff , but you are not telling the whole story are you.
The summer months tell a different story :
http://www.gridwatch.templar.co.uk/
During May , June, July the winter winds dropped to the point where at times in May, June and July the metered windpower fell to 10%, then 3% , 1% , and on at least one occasion,0.1% of demand .
Meanwhile nuclear power chugged on , delivering 6-8GW no matter what the weather was doing.
No one question that windpower under the right conditions can make a significant contribution to UK demand but it is unreliable at present, benefits mainly just a few of the population and at present, IMO, cannot alone be the basis, or even the major component, of a modern , power hungry society.
summer is for solar…
and in any case we have been getting more power from wind than coal this summer, now the coal plant shut down has begun
Griff: Glad it’s you. When it’s dark and stormy for a month, there won’t be any power, except the diesel generators, which every country and island using solar and wind have for backup. And they use those generators sometimes half the time. How much do diesel generators pollute?
Wind and solar are akin to the following scenario:
You have a car sitting in your driveway and you want to go somewhere but don’t feel like driving or you know it may be very difficult to park nearby. So you ring up and you are lucky there is one available immediately.
As a one-off this might be convenient, if a tad expensive, given that the cost will be far more than the fuel cost. Yes, I know that there are other costs involved in running a car, but you’ve already factored those into the need to have a car for work etc.
Now, how would you feel if the government made it a requirement to always use a taxi if one was available (your car being monitored for use against a taxi phone-in database) resulting in much lower usage of your car (despite the fixed costs) and extra costs for taxis.
This is equivalent to the current situation of renewables and the current mandates.
Does it make sense?
Who gains?
In one situation it is the wind and solar operatives/landowners, the other would be taxi owners/drivers.
The losers – Joe Public. Because it is an expensive (semi-compulsory) duplication of a cheaper solution to the requirement for transport.
What do you think would be the situation with regard to the numbers of taxis and taxi firms – yes a massive increase in the number of vehicles registered. Imagine the waste in terms of duplicate costs of manufacture, insurance, regulation etc. all for something not actually required.
SteveT
Oops,So you ring up FOR A TAXI and you are lucky there is one available immediately.
SteveT
And what was the percentage of consumption of that 18% ? And was all backup shut down during the generation of that 18%?
Too pre-post-modern. Don’t you know the climate white elephant needs to be built first, and the basic information on why it’s an obvious white elephant should come later? Prudent forethought is so last century.
Some video to share with your favorite wind-energy fan:
Oh the schadenfreude…
The number of those which happen each year is astronomically small. share that with wind farm opponents…
“astronomically small” is also the answer to such questions as
How many people want a wind turbine near their home
How many wind turbine farms are constructed without subsidy
How many green programs would exist without political insanity
When dealing with a power source that is already uneconomical, even “astronomically” small is too much.
https://www.carbonbrief.org/factcheck-how-often-do-wind-turbines-catch-fire-and-does-it-matter
“The CWIF recorded a total of 1,328 accidents involving wind turbines between 1995 and 2012. Of those, 200 involved fire. There have been no recorded fatalities and four recorded injuries from wind turbine fires, the IAFSS report says.
That’s 11.7 fires per year on average, or nearly one a month, the research points out.
While that might sound like a lot, in 2012 there were 225,000 wind turbines installed globally, according to trade association the Global Wind Energy Council. That means you could expect there to be one fire a year for every 19,230 turbines operating worldwide, on average.”
maybe this will help Griff
http://www.caithnesswindfarms.co.uk/AccidentStatistics.htm
And how many coal or gas turbine fires (or other incidents which destroyed an entire generator) were there during that time?
How many nuclear plant accidents?
And Griff, your stats are way off. In the last year mentioned, there were far more turbines than in the first year.
You cannot take the average incidence over 17 years and apply that to the number of plants in operation in the final year, when for many of those years the number of turbines was far lower.
In the US, and I think Canada, and probably most anywhere else, turbine fires don’t have to be reported. We really don’t have a good idea how many there are. From that Caithness link:
Many more on youtube. Note the most popular popup selections on youtube search after entering “wind turbine” are
wind turbine fire
wind turbine explosion
wind turbine accidents
wind turbine failure
wind turbine noise
This puts a new ‘spin’ on the old phrase ‘fanning the flames.’
“It’s important to ensure that science doesn’t underestimate the possible wind resources,”
I think this would be more appropriate: “It’s important to ensure that science doesn’t overestimate the possible wind resources”
They should have consulted yachtsmen first. Any yachtsman would have told you that the wind is ALWAYS more unstable around a headland, and Cape Wind sounds as if it is a headland.
I guess near on four centuries worth of seafaring sailing ship’s logs of conditions in the exact area weren’t available for inclusion in the report.
+1 Aaaargh, they be available, just they be saying things the greenies might not want to hear, matey…
Who cares? As long as Big Wind makes their dough, that’s what matters. Cape Wind was doomed from the start because of NIMBY politics. Opponents are nothing if not rank hypocrites. They love “green” energy, just not where they might have to look at it.
Interesting photo of the downstream conditions from a windmill. It is the only one that verifies of the weather modifications downstream. That’s what I complain about. There are no studies of the downstream areas. Unlike windbreaks, trees in a row, does this help the local area, or create problems. Does the turbulence change the local weather? How about, further downstream, or, the upstream pooling effect? If you block the flow here, does the wind blow heavier there? Man-made global warming created by ducting the winds?
In Iowa and other locations, the turbines keep crops from freezing, extending the growing season. It’s the same idea of the fans in citrus groves in the south.
Here’s an article on this question:
http://www.scientificamerican.com/article/wind-power-found-to-affect-local-climate/
Most unseasonal crop losses come during clear nights with no wind, from frost.
Frost cannot form if the wind is blowing over a few mph. Unlikely wind turbines will stir the air much when there is no wind to begin with.
If it could, farmers would have installed windmills and not expensive to run fans.
“Another potential beneficial impact: Because turbines mix up the air and slow wind speeds, they also could also affect the temperature around them, making nights warmer and days cooler.”
From: http://news.nationalgeographic.com/news/energy/2011/12/111219-wind-turbines-help-crops-on-farms/
My analogy may have not been the best or not clearly understood. Maybe this article will help.
Who pays for a damaged Cape Wind? The funders of the Big Dig (the rest of us) want to know.
Sounds like a pre-excuse for when the off shore wind farm doesn’t pan out like they thought.
I’m shocked, shocked, to learn that the air not only moves, but moves at velocities and directions beyond predictability. (Between ‘shocks’ I’m enjoying some first-rate commentary, thanks.)
They need to act fast. Pretty soon there will be no more Climate Ca$h, and the wind fakeindustry will fold like a cheap suit.
How can that be? Our windophiles assure us that wind is the cheapest form of power.
Yes, wind is free. However the means to capture it and put it to use is very costly.
Oil is free too, as is coal. Getting it out of the ground costs some money though, but not nearly as much per unit energy delivered as wind.
But the biggest difference is probably that the oil and coal do not appear and disappear unpredictably and intermittently.
For the wind industry to be anything more than a specialty niche in the power market, each of the devices will have to generate enough energy in its lifetime to reproduce itself while also providing reliable grid base load.
I can’t see evidence of that, can anyone show me?
So basically a wind farm would generate 11% of the nameplate rating instead of 10%.
A refresher on the facts of offshore wind power in the US:
1) Total potential for installed power: 900 GW ( Per the U.S. Department of Interior, Mineral Mining Service, MMS, in their January 2009 “Draft Proposed Outer Continental Shelf Oil and Gas Leasing Program 2010 – 2015,” )
The MMS stated:
“The U.S. Department of Energy (DOE) estimates that more than 900,000 megawatts (900 GW), close to the total current installed U.S. electrical capacity, of potential wind energy exists off the coasts of the United States, often near major population centers, where energy costs are high and land-based wind development opportunities are limited. Slightly more than half of the country’s identified offshore wind potential is located off the New England and Mid-Atlantic Coasts, where water depths generally deepen gradually with distance from the shore. Development of offshore wind energy technologies has the potential to provide up to 70,000 MW of domestic generating capacity to the nation’s electric grid by 2025.”
2) Costs for wind turbines offshore are higher than onshore, but will steadily decline as sizes increase and more units are installed.
3) Average wind speed is higher offshore, providing more output per turbine.
4) Improved technology has been developed (or is under development) by US Sandia National Laboratory, to allow offshore turbines to continue operating in gusty or very strong winds instead of cutting out to avoid damage. The new turbine is HAWT with blades downwind of the tower, and importantly, flexible blades that bend in the wind.
see http://energy.gov/articles/enormous-blades-offshore-energy
5) Energy storage via MIT underwater spheres allows wind power to be sent to shore on demand and in load-following mode. Net energy loss is approximately 20 percent.
6) US wind energy map shows the location and strength of offshore wind – http://apps2.eere.energy.gov/wind/windexchange/windmaps/offshore.asp
MIT underwater spheres?
Menicholas
August 12, 2016 at 11:17 pm
MIT underwater spheres?
Try this:
http://energystoragereport.info/the-promise-of-underwater-offshore-energy-storage-systems/
I particularly liked the bit “That means 1,000 such spheres could supply as much power as a nuclear power plant for several hours,” gushes the press release……….MIT researchers Alexander Slocum and Brian Hodder believe the build-and-deployment cost for the concept would come in at around USD$12m per sphere, which they say equates to $0.06 per kilowatt-hour, a commercially acceptable rate.
That’s US$12 billion for a “few hours” use of a nuclear plant. After that you have to wait until the wind array is functioning again, plus the time needed for the excess power to “recharge” the spheres! Seems somewhat expensive. Not counting the design and building of a means of deployment of said spheres ( the report admits that this is currently non-existent).
SteveT
There are plenty of grid-storage alternatives, if one does not care for MIT spheres underwater. Land-based pumped storage hydroelectric, the Okinawa-style ocean-and-land pumped storage hydroelectric, rail gravity storage, and high-capacity batteries all are viable alternatives.
The MIT storage spheres will be the economic choice as their installed costs fall over time.
You believe all that cr&p, do you?
What’s Santa bringing you for Christmas this year, Roger?
Mr Sowell’s problem is that he likes to cite really limited technology, like pumped storage, as if it were a practical solution to the intermittency of wind and solar, and come up with bogus objections to what could work, like nuclear.
One need only look at the grid stability in California’s ISO (CAISO, or Independent System Operator) and the abundance of wind power and solar power on the grid here. Solar at grid-scale routinely produces 8,000 MW of power during daytime peaks, with another 2,000 to 3,000 MW from solar rooftop systems. Also, wind power provides up to 4,200 MW and varies as the wind usually does. California manages just fine with some of the grid-storage systems described above: pumped storage hydroelectric, and batteries. It also helps to have load-following gas-fired power plants, essentially zero coal-power, and very little nuclear power.
The state law in California requires 50 percent of all electricity sold be produced from renewable energy sources by the year 2050. With very limited wind resources in California, solar power is the only resource that can meet that requirement. Grid stability requires that excess solar power be stored for up to 8 hours. Installed grid-scale solar power capacity will exceed 50,000 MW by 2030, and battery storage will reach at least 30,000 MW with duration of 7 to 8 hours.
What is also true is that the aging US nuclear plants, 99 of them at present, will all close within 10 to 15 years due to old age and unsafe or uneconomic operation. However, the many large pumped storage hydroelectric plants will continue operation, consuming wind power when it is in excess of grid need, and returning 80 percent of that stored power in peak demand.
The coal exhaustion problem is real, and imminent in the US. Denying that fact does not change the fact. Unless, that is, one knows where more coal deposits lie, that can be mined profitably at present prices. Such mines have escaped the notice of the experts at the USGS.
The national grid that relied on coal-power for more than 50 percent of all electricity must adapt to new forms of power, which will be primarily wind power, gas-fired backup, and grid-scale storage as the storage systems mature and price declines.
Or, one could laugh all this off as madness, and miss out on serious investing opportunities.
Roger,
What are you talking about regarding battery storage? Where? What type? My solar system would not have allowed by to tie to the grid had we installed batteries as I wished.
The last I read, Governor Moonbeam was demanding grid scale storage, but so far nothing is on the close horizon. Has there been a break through?
Thanks,
pbh
for McComberBoy,
Yes, there has been a major breakthrough both in batteries and on the legal side..
The DOE website below has a searchable database of grid-scale storage world-wide. One can filter the results to California, which shows 182 battery systems (“electro-chemical devices”) operating, under construction, or announced.
http://www.energystorageexchange.org/projects
The most recent large order is for 100 MW and 4 hours operation of lithium-ion battery to be installed in West Los Angeles by Southern California Edison.
As to a technology breakthrough, Nobel-prize winning physicist Dr. Alan Heeger of University of California at Santa Barbara has developed and filed for patents on a greatly improved battery that uses halogenated polyacetylene, HPA. His company is on the web at BioSolar.com. I wrote an article on my blog, and Anthony cross-posted it here on WUWT a few weeks ago.
https://wattsupwiththat.com/2016/04/08/this-new-battery-is-a-game-changer/
The HPA battery has many improvements over the state of the art Li-ion, including one-fourth the cost, twice the energy storage for the same weight, and essentially zero loss of capacity after thousands of charge/discharge cycles.
The status of installing home battery storage systems is the CPUC is still ironing out quite a few wrinkles. There should be more clarity and some decisions made by the end of 2016, as described in this document (apologies for all the legalese):
DRP Scoping Memo filed January 27, 2016 (Distribution Resources Plan)
http://www.cpuc.ca.gov/WorkArea/DownloadAsset.aspx?id=9372
The predicted outcome is that home battery storage for rooftop solar systems will be allowed soon, with certain conditions to ensure grid stability, safety, and affordability.
” aging US nuclear plants, 99 of them at present”
Since nuclear is an important part of the US power supply, aging is an important topic that is being addressed by the nuclear industry. We have already figured out how to make them last 60 years and are working on 80 years.
Of course wind turbines and solar panels are also aging. I do not think storage will be needed because of the failure rate with time.
“The coal exhaustion problem is real, and imminent in the US. ”
Yes and no. Running out of fossil fuels is not imminent when considering the life span of human or wind turbines. A good argument to wait to build wind farms until they are needed.
“No measurements exist of wind and turbulence around an offshore wind turbine’s rotor blades in the ocean in the U.S., because until now, none have existed.”
— How embarrassing. Maybe Mrs Jennings 4th grade science class can offer them all some suggestions for improving things.
I’m mostly curious about how nor’easters and icing will impact Deepwater Wind than I am about wind flow. However, a query from an Email list I’m on inspired me to hunt down the paper an take a closer look. The paper is available at http://www.windaction.org/posts/45573-on-the-predominance-of-unstable-atmospheric-conditions-in-the-marine-boundary-layer-offshore-of-the-u-s-northeastern-coast Not firewalled!
The paper uses data from low level airplane flights and the Cape Wind Met (Meteorological) tower, which was not as tall as the planned turbines. The paper refers to instruments at 20, 41, and 60 meters above MLLW (Mean Lower Low Water, a term I haven’t encountered before), the Deepwater wind turbines are said to be 270 feet (82m or so) tall, but that has to be the tower height, and even that’s too low.
https://www.gerenewableenergy.com/content/dam/gepower-renewables/global/en_US/documents/haliade-offshore-wind-turbine.pdf says “Hub height 100 m (or site-specific)” and “Rotor diameter 150.95m”. That means the blade tips will be shuttling between 25m and 175m, way in excess of the Cape Wind Met tower. BTW, these are 6 MW turbines with blade lengths 50% longer than any land based turbine I’m familiar with.
I imagine the Cape Wind folks figured their Met tower would cover the boundary zone over the rotor’s swept area and that air flow would be steady above the boundary zone.
The paper says that the air flow is more complex than that. The paper looks at data recorded from an airplane at flight levels 30 – 90 meters, so those are below the nacelle too!
All in all, I really don’t know what the implications are from this. A steady, stable air flow will have wind sheer, with significantly lower wind speed at the bottom of the rotor than at the top. An unstable air flow has much less sheer, but will have quite a bit of random motion, left, right, forward, backward and even up and down. Either way they’ll have some interesting forces, they may have more trouble dealing with the random, turbulent wind.