MAY 20

Looks like a giant belender for slicing and dicing whales, seals, dolphins etc etc, dont think this will go over very well/

http://www.marineturbines.com/...al_impact/

10 to 15 rpms isn't going to chop anything up. fish can avoid these things.

you probably rant against windmills because a bird get's killed.

damn you Jon, and people like you... friggin negative nancys all of you!!

as if whales, seals and dolphins don't have eyes to see the thing spinning slowly..

16 Meter diameter at 20 rpm is about 37 mph at the rotor tips.

take a couple of trawlers out of circulation. even out the impact.

or put a cage around the blades - only little fishies get hurt.

or sit there and cry "waaaaaaaah .. pore ole fishies" while your energy provider spews another ton of carbon into the air to keep you house warm and computer running.

Going by the size specifications on the website and your rpm values, the tips of the blades are moving at about 35 miles per hour. I think that packs a bit of a punch, yeah?

C=2(pi)r=2 x 10m x 3.14 =62.8m , 62.8 x 15rpm = 942m/min, 942/60min per sec = 15.7m/s =35miles/hour

Birds have eyes, but they're still getting killed by windmills.

In summation: this is an accident waiting to happen.

Considering that baseballs occasionally hit baseball players about 75-100 mi/hr and don't kill the players, I would venture to guess that the 35 mi/hr tip might bruise but would probably not kill.

On the other hand, if it's sharp, it might slice.

Cant wait to see the images of the first submarine to get stuck in it!.

A car that hits your while traveling at 35mph could very well kill you. Don't compare apples to marsupials. The mass of an item determines how much impact damage that it creates.

Put a friggin cage around it, dummies!

The last large tidal generator that was built caused a noticable slowdown in the earth's rotation. This will be no different. Extracting energy from the tidal current flow will have a severe cost.

What is wrong with your fish evangelists!? do you weep in front of the fish stall at the local markets? Idiots! Cage it or collect the fish bits for consumption, but spare us the fish love angst.

Not only does it slow the earth down, eventually it will reverse the spin of the earth. When this happens gravity will reverse and we will fly into outer-space and time will begin to flow backward! Oh Noes!

Well, it looks like these things are not that far off the coast so I am guessing that a whale will only find their way into one as they head to shore to beach themselves. Small fish can swim fast enough not to be bothered by them, even stuck your hand in a fish tank, the buggers are quick. Dolphins I believe have the speed and most likely smarts to avoid them. Seals do not tend to hang around moving objects and I would assume there are none int he areas these are placed. Sharks the same thing, not in the area and if so can move fast enough to move around the blades if they come close. What you really have to worry about is the green peace people whole will go out into the water to protest the no harm being done to fish and they themselves being slow bulky and dumb getting chopped into sushi for the fish to enjoy, that is the real concern.
-Cheers

What? Tidal turbines can slow down the Earth's rotation?!

Are there any studies to back this claim? Really, this is the first time I heard of such a thing.

!si ti naht ylsuoires erom raf nekat eb dluohs sihT
?elbacilppa yrev emoceb reve lliw siht fi rednow I
:p !stragnoc dna siht sdaer reveohw @ ZLOL

just cage it and be done with it ;)

You commenters are idiots, seriously.

What's a congart?

comments like the ones above are why a blog can never be taken seriously.


Putting a cage around a spinning blade in water disrupts the waterflow while adding complexity and weight to the whole unit.

Do they put cages around wind turbines? Of course not because it's a terrible idea.


And it would seem to me most of you have no idea what even causes tidal movement of water.
In which case, well, you shouldn't bother commenting on articles like this.

You can't extract energy out of a system for free.

Do they still teach basic science in school? You couldn't tell reading some of these inane comments.

OK... seriously, how could that thing slow down/disrupt the rotation of the earth? What do tidal movements have to do with the earth spinning?

p.s. please save all pretentious put downs... sorry not everyone is as edumacated as you all knowing "commentors"

Good post and thank you. Where'd you get the commenters, though?

This thing has about as much chance of slowing the earth down as the shoreline behind it. The energy it extracts is subtracted not from the whole, but from the energy that would have been stopped at the shore if it had not been absorbed further out.

Sheesh ... the internet is an international communications medium -- didn't anybody finish high school?

I dont think energy sources such as wind and current are a reliable long term solution. That energy that is converted would otherwise contribute to a warming or cooling in another region and by harnessing it, we are only disrupting these natural cycles. Changing weather patterns can affect temperatures globally to an extreme and end up ruining crops in unforeseen ways which some may rely upon for food. All I can see is famine, floods, and storms...hate to be dismal.

In the mouth of Strangford Lough, a large (150km²) shallow sea lough, the southern entrance to which is a deep channel about 8km long, called the Narrows. From Portaferry across the Narrows to Strangford is just 0.5km. About a third of the lough is intertidal.

The currents in between are extremely strong and fast - up to 8 knots (4m/s). During tidal movements there are whirl poools and all sorts, so the fish are used to watching out for themselves already.

This is potentially a sustainable solution for the area, in that it makes best use of local circumstances and knowledge. It would only be transferable to areas with similar geography, and is not a general tidal solution!

Well, I'm sad to say this, but for once I'm glad that the people in the comments area won't have a say in what happens regarding this project. Just like I don't have a say whether a multi national billion dollar corporation can go off shore and stick an oil rig or not.

So let them cry and complain about Whales as if they actually cared, but nobody will give a damn about what they're saying.

Sad as it is, maybe this is how human kind will move forward on certain issues.

Well, I'm sad to say this, but for once I'm glad that the people in the comments area won't have a say in what happens regarding this project. Just like I don't have a say whether a multi-national billion-dollar oil corporation can go off shore and stick an oil rig on the sea floor or not.

So let them cry and complain about Whales as if they actually cared, but nobody will give a damn about what they're saying.

Sad as it is, maybe this is how human kind will move forward on certain issues: through strong headed, forceful actions.

If this was my site, based on what I see here, I'd discontinue the ability to comment.

Two comments:

1. If whales, sharks, and generally all marine life worth looking out for can navigate the expanse of the ocean by use of their senses (to position themselves using magnetic and electric fields, water temperature and turbulence, etc.) they can avoid a big ole, turbulence causing, electricity producing, magnetic field altering turbine.

2. A cage is a good idea anyway, it won't affect this thing and they are used on many, many high RPM propeller driven under water devices with minimal affect.

id like to see an official source of some type regarding the slowing down of the earths rotation because of these generators. William bennett, do you have a source for your claim? also I agree that the fish arent likely to be taken out by rotor, but i wonder how the noise or electric current created would affect sea life.

alright the whole slowing down the earths rotation was a joke. relax people

Awesome - Won't kill as many fish as an oil spill...

Whew, thanks for clearing up that "stop the earth" problem. Now what are we going to do about the moon flying off into outer space?

Fastballs don't kill
written by Bill , May 20, 2008
Considering that baseballs occasionally hit baseball players about 75-100 mi/hr and don't kill the players, I would venture to guess that the 35 mi/hr tip might bruise but would probably not kill.

True story. Fastballs also don't have a ton of momentum.

First things first, just to clarify the rotors will actually be moving at 12rpm (I know people, who know people that are working on the project). Going on that basis, the actual speed at the rotor tips is as follows: (I've made sure this is in feet and inches seen as it's an American website)

So, 1 meter = 3.2808399 feet meaning the circumference = 16*3.2808399*pi = 164.913 feet

MPH = (C*RPM*60)/5280
= (164.913*12*60)/5280
= (118737.3603)/5280
= 22.488136...
= 22.49 MPH (Not 35 or 37)

Moving on, why are people so concerned about these “poor” fish? Couple of questions for you, did you enjoy your sushi last night? How about that fish supper that you ate? (Scottish reference there). Yes, it’s a crying shame that we are making progress with green energy by sacrificing the “poor” fish (sarcasm). Fish have been over farmed for years, has anything changed? Fish farming = dead fish. Furthermore, fish farming kills fish but think about it, are the boats doing anything good for the environment? I think not. So, to conclude on that matter, a tidal generator killing a few fish for greener energy is a good thing from the planets perspective.

In addition, the cage idea isn’t as good as people think. The amount of sediment, seaweed and other rubbish in the sea would soon block flow to the tidal generator, thus rendering it useless. But wait a minute, can’t these cages can be cleaned? The answer is yes. But, how often will this need to be done? Every 6 months? Every Month? Every Day? Who knows? Sure, there will be maintenance work on these generators, but why cost in cleaning of a cage? It seems pointless to me.

So, all that is left to say is “MON THE TIDAL GENERATORS!!!” (Translation: “May the tidal generators have a long and prosperous future”)

its infancy

I love how all the naysayers will attack a form of green energy by evoking images of the collateral damage to fish or birds, when their SUVs and other unhealthy habits have been destroying habitats and suffocating the Earth for decades. Serious. Let's think about the kind of progress that this is and not slam it because of its potential to mess with fish.

You'll notice that it's also been built in a really strong tidal current, where lingering fish and other animals aren't going to be just hanging around. That's what makes it a good energy source. The tidal activity.

I applaud this new technology. Technically it will slow the earth's rotation and the moon's orbit which causes the tides, but it would probably take millions of years to measure any effect. It would happen any way over time due to new land formations being the inhibitive force instead of metal screws. When speaking of slowing the earth and the moon, you need to realize what kind of immense power levels you are actually talking about. The moon has been dragging our planet's water up and down and over the rough ocean and tidal floors for a very loooooong time. Our adding a few pieces of metal to intercept that massive energy flux is almost nothing comparatively, but the power output capabilities for us are staggering because we are so small and insignificant when comparisons are drawn to gravitational forces. ;)

This is really exciting. Here in the USA we have a pilot project in Makah Bay, Washington State.


The key for sustainable energy is diversify: Solar, Wind, Wave, Hydro, Bio-Fuels.

Do all the cars driving on the planet cause noticable slowdown in the earth's rotations as well? I wonder if the Earth is really flat and we never landed on the moon after all. :P I certainly hope that was a joke I mean it made me laugh, but just cause it was so absurdly stoopid. :D

Aside from jokes, I think this is a very innovative solution to our growing problems. We live in a world that is built on instant self gratification and over consumption without "true" regard to the inevitable consequences. Everything has a price, and now we're finally seeing what that is. I think this is a good step in the right direction, finally.

FREE WILLY!

I LUV WILLY!

I agree...free willy indeed

8) 8) 8) 8) 8) 8) 8) :o :( >:( ;D :D ;) :)

Really good idea! Stumbled ;D

If you guys are SO worried about poor fishies getting hurt, do something! Ask the coucils responsible if they couldn't just put a lil cage around the things. The little fish will get through, but the current flowing around the turbines will just sweep them through.

Want to save sharks and whales then ask the Japs and Norwegians to stop hunting them. Tidal turbines will cut the earth's rotation etc. - I see idiots they are everywhere. sorry but some people here really are just too stupid to have access to a keyboard.

I think it's just super that someone actually thinks this turbine is going to slow down the Earth's rotation...

just imagine if everyone drove east at the same time!

You make me lol.

The reefs in Lochs and Fiords in the world are great sites. There is also the possibility of using the power source that has set Iceland free of petroleum dependence; geothermal power.
The idea that the insignificant reduction in tidal flows by power turbines is even close to the reduction afforded by a hard winter surface freeze is ludicrous to contemplate. Such absurdities! Please, do not exhibit your complete ignorance of geography, physics, and any connection with reality in the universe.
I'm happy to see the designers have a firm connection with reality; no cages!
Theory is no proper replacement for reality.

ok i know this is only a comments board but:
1. The angle lag of the tides and the moon is naturally causing the earth to "leak" angular moment to the moon through torque. i.e. the earth is very gradually slowing down and the orbit of the moon is moving slowly away(approx 4cm/year).
2. The gravitational force from the moon (and a bit from the sun)causes Earth's tides.
3. You can't extract energy for free from a system.

Combining these three together its at least a possibility that extract tidal power causes rotational slowing, however i think one extra tower off the Irish coast is not going to cause any noticeable effect(the world would have to be as dependent on tidal power as it is now on fossil fuels to see any kind of effect).

Slowing down the earths rotation is such a funny notion, and for so many people to have thought it a serious comment cracks me up. But seriously, to save the whales lets put safety airbags on them so they will just bounce off the blades!!.

Slice and Dice
To make the enviraholics happy, babby booties could be put on the ends of the blades to protect the blind or vision impared whales and (fishies)

Before the days of steam engines, large sawmills were run by impounding water at high tide and using an undershot wheel. This happened in Darien, GA. This type of energy extraction could be made portable and used anywhere there is a sizable tide difference and a shallow enough seabed to build the plant.

That sounds good to me! I have also been thinking of the undershot wheel coupled with a generator for use under bridges in many tidal inlets. The flow wouldn't have to be that great with the proper gearing.

As far as the fan shroud idea goes, a shroud is frquently used in a ducted fan situation where the "liquid" (air) runs off of the blade tips in a vertical direction in relation to the spin instead of passing through. The runoff is considered "wasted". Of course the blade chord is wider at the tips than the general concept of a double tapered blade and most often, more blades are used. This allows a larger airflow with a smaller diameter.

P.S. Look at the cooling fans in your computers!

Me and Henny Penny are worried that the moon may fall from the sky if too many of these devilish machines are built because they obviously interact with the moon's gravity!The fish being shredded in the blades however, will only serve to make a good cold chowder for the local bottom-feeders, who in fact may actually appreciate it.

wow, i see from pictures it's got adjustable
blades.
also if they could find a place where there's
sufficient tidal movement -AND- wind,
they wouldn't need to leave such a big carbon
footprint smelting so much iron
:o

Let's rev it up. So, a few dolphins and whales will bite the dust, but are we supposed to live like Neanderthals?

1. The fish slaughter issue is a complex one, the blades cannot be caged unless the cage itself were to be designed according the little understood principals of fluid dynamics that would in fact either negate their own disruptive friction (which causes the current to become choppy and not effective for use with a blade-based turbine) or enhance the directional current. I'm sure it has been considered and disregarded due to the money and engineering necessary to do it. However, it is key to note that without a comprehensive study of the biodiversity profile of the area one can not say if there even are large fish in the area to be chopped up in the first place (small fish are durable).

2. Gravity is not entirely understood by physics, is created by the emission of gravitons? Is it due to the principals of relativity and the accelerating expansion of the universe? Does gravity decrease over time for all objects as their initial mass/energy succumbs to entropy? Where does the energy necessary to form a gravitational bond between two bodies of mass originate int he first place? It is all theoretical, and so unless the effect of the turbines on the gravitational interaction between the earth and moon could be studied (which would take hundreds of years) the point is a moot one.

3. This is a step in the right direction, however it is just one step. This installation is essentially just a test, though a theoretically profitable one. Many other systems have been proposed utilizing tidal energy for electrical generation. For instance, what ever happened to those fishtail and kelp-based designs for current-based generators? Could those not also be applied in high-motion tidal regions such as this one?

I wonder if they did any research on turbine style blades. I've seen some turbine style windmills - they work well and are visible to birds.

Charles Precht
Sustainable Design
www.sustainablehomeplans.com

If the earth build trillions of this thing it is a chance of 1 out of 458785723857923587248935 so I doubt tht will happen put a cage around it and it will be a good source of energy =D

@omegavector, Thanks for explaining that to people.

It is now February, 2009 and the Irish coast is not red with whale blood nor has the Earth stopped spinning. If anything, the electric eels are growing a bit larger these days for some reason.

I am 'over the moon' about technology in general and ecstatic about new power generation - am pro nuclear power (it’s not as dangerous OR as expensive as people make it out to be if it is culminated in a modern forms ie. Pebble Bed Reactors)
But, I do have a justifiable problem with whale deaths as they are much more vulnerable to extinction than the little fishies the sarcies make mention of. And, extinction is the issue here
Extinction, for many reasons has very serious implications for humans.
And I also think, incidentally, that mankind is an amazing aspect of the universe - we need to think about our quality of life as well. Extinction seriously threatens our future.
Yes there has been mass extinction before but seldom to the extent that man is affecting on the environment at the moment (and on the verge of intensifying astronomically)

The few mass extinctions that have occurred meant life took millions and millions of years to recover - man cannot afford this situation.

As far as the tidal turbine is concerned these pose a significant threat to whales and this needs to be kept, acutely, in mind when building them.
The seas might be trechurous but no sea creature the size of a whale is capable of negotiating the complex and dangerous dynamics of a hydra turbine blade - no matter how many eyes they might have or how slow the (large) blades are turning.
The stress alone from being thumped on the back or nose by a 25 meter polystyrene blade is enough to kill a whale - they simply will have not come across anything like this before.

Cages are not practical - too costly to maintain and they will have a negative effect on the efficiency of the turbine.

Turbines can affect the behavior of the earth but you would need 100s and 1000s of them all over.

A possible solution would be to deflect the approach of whales by some sonic irritant.
Problem is, the sea is so unbelievable polluted by sound - military sonar detection, oil and gas sonic exploration and ship engines that are excruciating load. I know, I have dived in some of these conditions. And whilst earthquakes are a thousand times worse - again I know, I have been diving when an earthquake occurred in the Middle East - they seldom happen and are not continuous.
These continuous man made, high decibel sounds are already causing whales stress and destroying their ability to navigate, thus we see evidently more beachings and whales venturing into areas where there is no food and just dying.

Coupled with the fact that Japan thinks it cool to start hunting thousands of whales again, which they are doing right this minute, breaking international law and in turn evoking a 'if they can why cant we' reaction from Neanderthalic parts of Norway, Iceland, Faroe Islands and to a lesser extent Denmark, our whales are in deep trouble again.

However the greatest savior to us all is not turbines or caged turbines or CO2 decreases or GM crops or Renewable energy sources or energy saving light bulbs.
All the above are completely insignificant to the threat looming now.
It doesn’t matter how many grids we convert to sustainable energy reciprocates or how many energy saving light bulbs we install - it is all in absolute vain.
Why! Imagine this.
You have a street in a village that wants to cut its energy consumption (go green as is the fashion)
The village has 10 street lamps consuming 10 kilowatt hours of power per month - just as a simple example.
Each month the council replaces 2 street lamps with an energy saving solution cutting the consumption of the 2 lamps by 50%
The first month the street uses only 9 kilowatt hours of electricity and the second only 8 kwH
By the fifth month the council has replaced all ten lamps with energy saving solutions and the street (as it was) only uses 5 kwH of power.

"Hooray we have gone green" some chant in the street - "we saving energy" - But this is not the reality. The wise sit in their homes no more settle than before the new lamps were installed.
Those in the street chant "let’s change more"
While the local councilor doing his shopping then scurries off deeply concerned. For, he knows, changing the lamps has cost the council $50 000 and the people are still not happy.

And, And, And in each of the months that 2 lamps have been changed, each month a new home has been added to either side of the street and with it 2 more lamps consuming power - there has been no saving on the power being used on the street only financial cost. And with the new factory down the road even more power is being used.

You see reducing our energy consumption is a fallacy - every gas guzzling 4 x 4 taken off the road in America and the United Kingdom and Germany for that matter is replaced by 10 less guzzling Tata's in India and China and 10 Tata's still consume more gas than 1 'Evil' 4 x 4.

The problem is really gargantuous and completely unsolvable using present trends. But, of course, for now there is alot of money to be made in 'green euphoria'
Ladies and Gentlemen according to most credible organizations
THE HUMAN WORLD POPULATION INCREASES BY ROUGHLY
200 000 EACH DAY.
Our economic and political systems can only function, at present, if we have increasing populations. We need to change this fast or blind fold our children.
But, then again our children are becoming so desensitized and apathetic to what they see and do - we are beginning to blind fold them already - Humans are amazing, but are we amazing enough to save ourselves?

Anyone interested in the plight of whales should visit the Sea Shepard Conservation Society - they are currently at war out at sea now - unlike Greenpeace - they actually are physically doing something about it.
Greenpeace and Sea Shepherd work differently to achieve the same objective - please support them.

love all this debating...wouldnt life be more interesting if it did make the world spin backwards... oh and greenpeace might not be so peaceful...just a hint

Comparing the tidal turbine to a "fan" is not a valid comparison. A fan adds energy TO the fluid. A TURBINE extracts energy FROM the fluid. Just the opposite is occurring. And do not assume the fluid dynamics are the same. They are not. That's why they are shaped differently. You also cannot assume that any fluid that "spills" off the end of the blades is "waste" and therefore could be conserved with a shroud. It is more complicated than that.
The problem with you environmental wackos is that you said oil derricks in the ocean were "visual pollution" and eyesores... but you are ok with wind and tidal turbines! Hypocrites. Nuclear energy is SO much more "clean", efficient and effective.
By the way, the heavy use of composites and hydraulic fluids in wind and tidal turbines involves TONS of petroleum derivatives.
And one more thing, those of us involved in the profession call them “tur-bins” in the USA, not “tur-BYNES”…. That’s what the Brits call them.

some interesting comments from the wise in the world....im an engineer doin a project on a tidal turbine like the one mentioned....well there will always be problems in whatever humans do...i just like the idea of extracting energy in novel ways.....too much of anything is always bad(wind turbines, tidal turbines, nuclear, coal).....wise energy use is always better than generating more(even from green energy).....better said 'try not to waste when u are not using it'....and for all the enviros out there humans are one of the major causes of all probs on earth...better concentrate on reducin populations....

Maybe these will get rid of some of those dolphins that alway tangle up the nets and take up space
the flow of the water should suck a lot more fish in the nets and keep us from having to waste fuel looking for fish.

This is a terrific concept and test idea. I am sad to read through so much sh*t.

We should be looking to be greener and greener, hell lets start making these out of recycled plastics/ metals.

Projects like these usually come up against so much political challenges from people who although think they are doing better for the enviroment are actually hindering scientific progression to make a better planet.

There are two simple choices we have:

1 - We go back to the stone age, no more travel, tv, computing, insulation (other than natural fabrics) oh and we will also need to probably kill about 2/3rds of the planet as we are already over populated and locally farming will not be able to sustain populations.

2 - We continue the evolution of our technolgy species, we continue to research and develop greener energys, we continue to grow as a global community through the power of technolgy and eventually we may even reach out and populate into outer space.

Crazy as both options are opposite these are the two fundamental views once all the pleasentries are stipped out.

I choose option 2!

I think that the whole idea of harnessing the power generated by tidal flows is fantastic. There are many types of tidal turbines some of which lie on the sea bed and can't even be seen so no visual polution. No sound pollution either. No need to include a backup fossil fuel power station in costing exercises as tides flow consitently in and out day after day. This technolofy is in its infancy. Based on advances over the last 20 years in wind turbines I dare say that they will be making tidal turbines that generated 5 or 10 MW within a few years. Also by dumping rocks in a 'V' formation either side of the turbines thus creating an underwater vortex, tidal flows that are currently marginal but close to electric grids could be made viable.

Let the show begin and get us away from our dependancy on fossil fuels

Great! Don't read all the retarded comments like "Slices up whales, mashes up fish, causes the Earth rotation to slow down" etc etc.

I don't think I've been on another site populated by more morons than this one.
Despite all the complaining about birds getting hit by windmills, I have yet to see a bid on the ground by any of the 50 windmills in my area.
The sky is falling ... the sky is falling!!!