Whales and Offshore Windmills

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
F

FWT

Guru
Joined
Dec 10, 2020
Messages
1,599
Vessel Name
Resilient
Vessel Make
Helmsman Trawlers 38E
This is pretty heavily skewed propaganda.
 
FWT, funny you caution 'brief mention' of political slant. You were joking, right?

You're not wrong about technical challenges, though. Like all innovative devices,
wind turbines aren't immune from the development curve. New and better designs
will continue to appear. Now, if there was just some way to get rid of the subsidies
for the oil industry!

https://www.imf.org/en/Topics/climate-change/energy-subsidies
 
Last edited:
Aside from tech issues that face the turbines even when ashore....

Building and maintaining them in the offshore environment is mindboggling. Sure it can be done but it is hugely expensive.

My old assistance tower boss got out of the little leagues and started betting on wind farms 2 decades ago...none have been built yet in his area and not sure any projects are even in the early stages other than leases and a few approvals. But it must not be dead yet as he just bought a 200 and some foot vessel for wind farm construction/maintenance.

He has told me or I have read some of his writings about much information that is incorrect on both sides of the fence on this topic...wouldn't discount general info, but specifics I am skeptical over.
 
Technically the article is a joke.

…But long blades spinning rapidly can have the tips break the sound barrier,…
 
Larry M said:
Technically the article is a joke.

…But long blades spinning rapidly can have the tips break the sound barrier,…
Click to expand...
The sound barrier is a problem for any airfoil not intended to exceed it.
A wind turbine would have to experience multiple failures for rpm to get so high.
The blades' angle of attack are always being adjusted to adapt to the wind speed.
The blades also lose efficiency if the rpm exceeds design limits well before the
sound barrier at the tips.
 
Pretty sure many windmills now turn very slow no matter the wind speed and there is variable gearing that generates more power as wind speeds go up.
 
psneeld said:
Pretty sure many windmills now turn very slow no matter the wind speed and there is variable gearing that generates more power as wind speeds go up.
Click to expand...

Yes, if anyone has seen a wind turbine move, they would easily see that the bird would need to be blind to fly into it. The article is laced with the verbiage of those with multi-million dollar waterfront homes and fossil fuel lobbyists.
 
Certainly folks can just put aside the politics, which isn't the point.

Some folks here know a lot more about the engineering challenges than I do, and I'd love to understand how real they are.

But I'm not surprised to hear of the problems. A community college I know used to have a windmill on the edge of the campus. It wasn't functioning more than it worked. After maybe 5 years they got rid of it. That was on land. Easier to service.

If the barriers are real, at least today, there is one less thing for us and whales to run into on the water.
 
ESI energy has been fined about $8 million for hundreds of eagle kills at their wind farms located in 7 different Western states. Expert testimony said that as wind farms increase in numbers bird kills will continue until eagle populations in impacted areas are driven to near extinction.

This is not a new issue with bird kills globally rising due to burgeoning wind farms. Unintended consequences is the term used at various state agencies with the increased use of wind farms.

Globally power generation is largely a government or state owned endeavor with legal action for bird kills largely muted. In the US private and public companies are open for legal action with cease and desist orders or large fines emanating. Unfortunately, once again follow the money.
 
But scientists say there’s no evidence to support a connection between the two.
From Maine to Florida, 178 whales have died, and scientists have examined about half of the incidents. Of those, about 40% were because whales were struck by ships or got tangled in ropes or nets in the water.
Ørsted’s New Jersey head of government affairs, Maddy Urbish, said the vessels the company had contracted to do its survey work haven’t “experienced any marine mammal strikes during offshore survey activity in the U.S.
Click to expand...
Above from CNN link HERE

Some tidbits can be extracted. 40% of 50% of 178 were struck by ships or tangled in nets. So of 178, so 35.6 strikes confirmed and double that for the ones that were not tested.
if you read the whole article you will know that experts are sure the windmills and the work to install them played zero, nada, no part in any death of a whale. Then there were scientists who also agreed, and as we all know science does not care what you think.
 
Wow, what spew. This "news" outlet is a Bulgarian company called ABC Media Limited" to make it sound legitimate, when its just one disgraced former hedge fund guy. And the site espouses anonymous authorship. Nice way to spew garbage while dodging any credibility checks. I don't know why people bother reading this trash.
 
Because if it is on the internet it must be true…
 
Shrew said:
Yes, if anyone has seen a wind turbine move, they would easily see that the bird would need to be blind to fly into it. The article is laced with the verbiage of those with multi-million dollar waterfront homes and fossil fuel lobbyists.
Click to expand...

Bear with me, math is following...
The current 'large' offshore wind turbines are the 6MW size which
have a rotor diameter of 492 ft. The tips cover 1545 ft per revolution.

At sea level in normal conditions the speed of sound is 1125 ft/sec.

The 6MW turbine turning 15 rpm (.25 rps) will have a tip speed of 386.25 ft/sec.
The same turbine turning 30 rpm (.50 rps) will have a tip speed of 772.5 ft/sec.
The same turbine turning 45 rpm (.75 rps) will have a tip speed of 1158.75 ft/sec,
and thus the blade tips will now be breaking the sound barrier.

At the rpm of a record player (of your youth).

Even at the sluggish 15 rpm, the tips of the 6MW turbine are going over 263 mph.
 
Last edited:
KnotYet said:
Bear with me, math is following...
The current 'large' offshore wind turbines are the 6mW size which
have a rotor diameter of 492 ft. The tips cover 1545 ft per revolution.

At sea level in normal conditions the speed of sound is 1125 ft/sec.

The 6mW turbine turning 15 rpm (.25 rps) will have a tip speed of 386.25 ft/sec.
The same turbine turning 30 rpm (.50 rps) will have a tip speed of 772.5 ft/sec.
The same turbine turning 45 rpm (.75 rps) will have a tip speed of 1158.75 ft/sec,
and thus the blade tips will now be breaking the sound barrier.

At the rpm of a record player (of your youth).

Even at the sluggish 15 rpm, the tips of the 6mW turbine are going over 263 mph.
Click to expand...


How fast do those turbines turn? I thought the big ones (they are all big now) were synchronous.
 
KY
Your speed calculation appears spot on. Early blades are now being replaced due to dust and debris wear affecting blade efficiency. Lots of data and information is being analyzed as time reveals necessary design and operational changes.

Unfortunately winged creatures cannot outrun or always avoid these fast moving turbine blades. There are ongoing studies to assess what impacts, if any, on marine mammals' sonar systems offshore wind farms low level harmonics may create.

I've taken TT's advice and not delved into the thumbnail that started this thread. So long as whales can't fly they should be safe from above water stuff though.
 
The author of that article cracked me up. I'd discuss it, but I'd be breaking the first rule of fight club.
 
twistedtree said:
How fast do those turbines turn? I thought the big ones (they are all big now) were synchronous.
Click to expand...
I have no inside knowledge beyond what I read but I think they are kept to 30 rpm or so.
Also pretty sure the rpm vary with wind speed so non synchronous AFAIK.
 
Not in the business, so one article may or may not be accurate...but if this one is.... 150mph is a long ways from the speed of sound.

https://www.semprius.com/how-fast-d... 10 and 20,may easily top speeds of 150 mph.

Conclusion
Don’t be fooled by the seemingly slow rotation of a wind turbine. Those blades pack a punch! Rotating objects reach higher speeds at their edges, and so the blades of a wind turbine may reach speeds of over 100 miles per hour at the tip, with the largest blades breaking 150 miles per hour on especially windy days. Longer blades have higher tip speeds, as the larger diameter gives the blade more room to reach higher speeds. Engineers actually design the turbines to rotate at a given speed depending on the wind velocity. This is called the tip speed ratio. This affects the turbine’s power generation, as well as several other factors. The blades are made of specialized materials, and are crafted to be aerodynamically efficient so they can more easily cut through the air.
 
I suspect that vertical axis wind turbines will become more popular to deal with high speed wind conditions and bird deaths. They are not as efficient as the traditional horizontal axis designs but when you factor in reduced design, construction and maintenance costs I think they will be comparable.
 
psneeld said:
Not in the business, so one article may or may not be accurate...but if this one is.... 150mph is a long ways from the speed of sound.

https://www.semprius.com/how-fast-d... 10 and 20,may easily top speeds of 150 mph.

Conclusion
Don’t be fooled by the seemingly slow rotation of a wind turbine. Those blades pack a punch! Rotating objects reach higher speeds at their edges, and so the blades of a wind turbine may reach speeds of over 100 miles per hour at the tip, with the largest blades breaking 150 miles per hour on especially windy days. Longer blades have higher tip speeds, as the larger diameter gives the blade more room to reach higher speeds. Engineers actually design the turbines to rotate at a given speed depending on the wind velocity. This is called the tip speed ratio. This affects the turbine’s power generation, as well as several other factors. The blades are made of specialized materials, and are crafted to be aerodynamically efficient so they can more easily cut through the air.
Click to expand...
Beaufort 9, a not uncommon 51 mph, at a tip speed ratio of '8' exceeds 400 mph.
I'm not saying it would be permitted by the control systems but that is only a lazy
22.8 rpm for the typical 6MW offshore wind turbine. More than halfway to Mach 1.
 
Last edited:
I don't know why, but every article I am readings says much slower..... why the differences? Sure things can exceed op limits, but they aren't designed to. My guess is that as blades get longer, they keep the RPM lower to keep the tips manageable.... works that way with helicopters..... at least what I am familiar with. :D

https://energyfollower.com/how-fast...s,direct relation to the velocity of the wind.

"You will need to know the length of the blade and the traveling circumference the tip of the blade takes in a single revolution. This is done using the equation 2∏r (twice the radius multiplied by pi, 3.1415)

Therefore, a blade measuring 120ft. X 2 = 240ft.

Multiply this by pi, equalling 753.96ft. This is the circumference of the turning circle.

If it takes 4-seconds for the blade tip to travel that distance, in feet per second the speed is

753.96 / 4 = 188.49ft/sec

To convert this to mph it should be multiplied by 0.681818182.

This particular wind turbine turns at 128.5mph.

This is relatively slow as large turbines can achieve speeds of 180mph before cut-out methods react.

The Maximum Speed of a Horizontal Axis Wind Turbine
All turbines are designed to operate to maximum speed, with maximum efficiency. Known as the RATED SPEED, or SURVIVAL SPEED, once severe storms hit and the wind speed breeches safe limits, the turbine needs a fail-safe to protect damage to the blades or the motor."


https://www.ge.com/renewableenergy/...61400-3 Rated,4 - 11.5 rpm Tip speed 90.8 m/s

Wind Turbine: Class I-B IEC-61400-1 / IEC-61400-3 Rated power 6.0 MW (net after transformer) Cut-in wind speed 3 m/s Cut-out wind speed: (10 minutes average) 25 m/s Grid frequency 50 / 60 Hz ROTOR Rotor diameter 150.95 m Blade length 73.5 m Rotor swept area 17,860 m2 Rotor speed range 4 - 11.5 rpm Tip speed 90.8 m/s (203 mph).
 
Last edited:
Found it ludicrous given 100 year event frequency recently art closes with no effect from MMCC. Believe although mechanics are produced by multinationals blades are made closer to where the farm is going to be. Not an insider so have no direct knowledge but possibly quality control has something to do with failure rate.
In my area the main complaint has been the thump they produce which can be heard quite a distance off. Enough so it affects house prices near the land based ones. A pleasant surprise with the offshore ones is general agreement theres good fishing near their bases.

Our local nuclear power plant closed. Hydro from Canada is expensive. We have no coal burners. Although in the northeast there’s been a marked increase in solar fields and wind. The regional electric bills for domestic customers seems to have tracked inflation. We sell electricity. Our contract is much less favorable then what we got on a prior house 15y ago. but still revenue positive and will continue to be so even after our stipends and tax percs time out.
Suspect the Siemens and GE contracts were priced at a pre inflation time . Those became overly optimistic as regards true costs to the extent of becoming losses. Probably the same thing occurred in New Hamster.
 
I am seeing political creepage into the wind issue. How about asking the average German their opinion on wind/solar?
 
We have entered the age when science depends on your political leanings. Is climate change real ? Is covid real ? Are vaccinations effective ? Was the lunar landing real ? Is the earth flat ?

These questions seem to get progressively ridiculous, but there are large swaths of people that will debate each of these topics.

We need to get back to teaching critical reasoning and civics in our public schools!!
 
Benthic,

I agree. If I could only ask on question on a high school graduation exam, it would be “When you flip the switch why do the lights come on?”. Come to think of it, that might be a good interview question to ask a potential employee.

Tom
 
Love that post Benthic

. Your entitled to your opinion but not your own facts.

Problem now is the difficulty of folks parsing out what’s factual. It’s not exclusively education although that’s a major contributor in my view. Have a daughter with a masters in leadership. Quite successful. Works in NGO fundraising for cancer research. Not a dumb bunny. Nevertheless has difficulty parsing her facts.
There are experts. Perhaps they know more than you about a particular field. Perhaps you can learn from them. Sometimes you don’t have the background to understand their language nor concepts. Apparently now that makes it ok to dismiss what they say and accept bogus “facts”.

My attitude is when you stop learning they had better thrown dirt in your face or they soon will. I have just as much respect for the diesel wrench teaching me something as the Nobel laureate lecturing me. Think a major contributor is the arrogance some people have making them unable to learn new ways to look at things. This opinion comes from the hours spent having people tell me I’m wrong. I read this on the internet. You then give them the science after explaining why the internet was misleading or biased or superficial. Time necessary but wasted.
 
Last edited:
One of the greatest wastes of time are topics on TF that are debated by people with neither the personal or professional experience or even the research necessary to debate some topics. They approach it from their limited background as if their opinion/experience in one aspect of boating applies to all.

A good example is the daytripper/weekender vacationer discussing boats for long term cruising or live aboard.

Or the fisherman versus the cruiser versus the dock condo.

Or the blue water guy versus the looper/coastal cruiser.

The list goes on and on.

Not that some tidbit don't overlap, but perspective is too often lost.
 
Last edited:
tpbrady said:
Benthic,

I agree. If I could only ask on question on a high school graduation exam, it would be “When you flip the switch why do the lights come on?”. Come to think of it, that might be a good interview question to ask a potential employee.

Tom
Click to expand...

TP
Surprisingly way too many well educated adults can’t answer the light switch question. Some years ago a smart friend was giving testimony about a coal mine his company was pursuing. One of the panel members questioned the need for the coal mine saying coal wasn’t needed but instead just electric power.
 
You must log in or register to reply here.

Latest posts

Back
Top Bottom