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Author Topic: Will this buoyancy engine-based generator work?  (Read 75293 times)

Offline Geezer

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Will this buoyancy engine-based generator work?
« Reply #125 on: 01/11/2011 21:30:46 »

Generator work done = Pontoon work done = Storage Vessel work done.



IMHO, that's a dangerous way to look at it, and it can easiliy lead to confusion, QED.

It should be;

Tide work done = all lost energy + captured energy.

The tide is the source of the energy, not the pontoon.
 

Offline Mootle

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« Reply #126 on: 01/11/2011 22:03:02 »

Generator work done = Pontoon work done = Storage Vessel work done.



IMHO, that's a dangerous way to look at it, and it can easiliy lead to confusion, QED.

It should be;

Tide work done = all lost energy + captured energy.

The tide is the source of the energy, not the pontoon.

You're leaning against an open door here - my point is that it works out all ways around, the only question mark relates to the system efficiency. Turbines and generators can work very efficiently if correctly matched to the application and this should be the main input for a well designed system. It is more difficult to establish the overall system efficiency. This will be a function of the the pulley system, the additional buoyancy needed to drive the ascent phase, allowances for coral growth etc, trimming losses (governing swell,) cable stretch, Pontoon sinkage, down time for maintenance / unsuitable operating conditions.... 
 

Offline Bored chemist

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« Reply #127 on: 01/11/2011 22:11:33 »
"would you not agree that if the Buoyancy Engine was set to work today, the given revenue figures would be achievable according to the rough order energy balance that has been agreed?"
My deliberately absurdly high estimate of the combined tariffs and subsidies was the equivalent of 4 times the actual value of the electricity produced.
I think your figures came out at something like half that figure.
It doesn't matter because, as I pointed out, many times,

Unless you can show how you are suddenly going to make this scheme a lot cheaper, it will never "break even" because the guessed revenues will never exceed the cost of paying the interest on the capital investment.

Worse, even if you could make it break even, it would still be a couple of orders of magnitude more expensive that just buying an absurdly expensive system.

I have asked the same question plenty of times and you don't seem to understand the importance of it.
How are you going to make your system ten times cheaper than the scrap value of the pontoon?


Oh, BTW, I write, and review business cases for the government.

We do take account of the fact that the plug might get pulled and, if that looks likely, we simply don't support the work. We don't do work that is likely to depend on long term support because that's not a good use of the investor's capital. So that's "When writing a business case the revenue is calculated based on the extant government incentives." scuppered.
 

Offline Geezer

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« Reply #128 on: 02/11/2011 04:53:44 »

Generator work done = Pontoon work done = Storage Vessel work done.



IMHO, that's a dangerous way to look at it, and it can easiliy lead to confusion, QED.

It should be;

Tide work done = all lost energy + captured energy.

The tide is the source of the energy, not the pontoon.

You're leaning against an open door here - my point is that it works out all ways around, the only question mark relates to the system efficiency. Turbines and generators can work very efficiently if correctly matched to the application and this should be the main input for a well designed system. It is more difficult to establish the overall system efficiency. This will be a function of the the pulley system, the additional buoyancy needed to drive the ascent phase, allowances for coral growth etc, trimming losses (governing swell,) cable stretch, Pontoon sinkage, down time for maintenance / unsuitable operating conditions.... 

Your pontoons are capable of producing 588.6MJ in 24 hours which means your efficiency is 44.1%

How does that strike you?

« Last Edit: 02/11/2011 06:21:01 by Geezer »
 

Offline Mootle

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« Reply #129 on: 05/11/2011 09:06:35 »

Generator work done = Pontoon work done = Storage Vessel work done.



IMHO, that's a dangerous way to look at it, and it can easiliy lead to confusion, QED.

It should be;

Tide work done = all lost energy + captured energy.

The tide is the source of the energy, not the pontoon.

You're leaning against an open door here - my point is that it works out all ways around, the only question mark relates to the system efficiency. Turbines and generators can work very efficiently if correctly matched to the application and this should be the main input for a well designed system. It is more difficult to establish the overall system efficiency. This will be a function of the the pulley system, the additional buoyancy needed to drive the ascent phase, allowances for coral growth etc, trimming losses (governing swell,) cable stretch, Pontoon sinkage, down time for maintenance / unsuitable operating conditions.... 

Your pontoons are capable of producing 588.6MJ in 24 hours which means your efficiency is 44.1%

How does that strike you?


Without trying to second guess your calculations did you take into account my comment:

'Therefore, there is scope to engineer an arrangement such that both Storage Vessels operate from one Pontoon, which carries a number of operational and financial advantages.'
 

Offline Mootle

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« Reply #130 on: 05/11/2011 09:21:43 »
"would you not agree that if the Buoyancy Engine was set to work today, the given revenue figures would be achievable according to the rough order energy balance that has been agreed?"
My deliberately absurdly high estimate of the combined tariffs and subsidies was the equivalent of 4 times the actual value of the electricity produced.
I think your figures came out at something like half that figure.
It doesn't matter because, as I pointed out, many times,

Unless you can show how you are suddenly going to make this scheme a lot cheaper, it will never "break even" because the guessed revenues will never exceed the cost of paying the interest on the capital investment.

Worse, even if you could make it break even, it would still be a couple of orders of magnitude more expensive that just buying an absurdly expensive system.

I have asked the same question plenty of times and you don't seem to understand the importance of it.
How are you going to make your system ten times cheaper than the scrap value of the pontoon?


Oh, BTW, I write, and review business cases for the government.

We do take account of the fact that the plug might get pulled and, if that looks likely, we simply don't support the work. We don't do work that is likely to depend on long term support because that's not a good use of the investor's capital. So that's "When writing a business case the revenue is calculated based on the extant government incentives." scuppered.

You are presupposing which way the future FIT scheme will go. I've already indicated that the current uncertainty would need to be declared:
 
'It is true that the FIT scheme is under review and as such that uncertainty would have to be declared.'

Your difficulty comes from not being able to distinguish points of view from fact. The fact is no costing claims have been made. I've set out why I don't think the assumptions made are reliable. For now I will press on with the scaled model animation, after which reasonably accurate costs can be established.

We seem to be going around in circles so unless anyone has some new questions I declare myself out of the thread for the time being.

Once again, thanks to all that took the time to comment.
 

Offline Bored chemist

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« Reply #131 on: 05/11/2011 14:21:39 »
This isn't a POV, it's a fact.
I can get the same nominal electricity generating potential as your machine for something like £2.4M

It's also renewable power, so it would presumably get the same FIT. (Granted that is a POV, but I think it's a reasonable one.)
So, unless you can build your scheme for less than that sum your system isn't financially viable.

It's also a fact that your rig needs a big pontoon.
It's a reasonable POV to say that it's in many ways similar to a ship. The stresses on it are different, but comparable (actually they are probably more difficult to manage).

It's not an unreasonable POV that shipbuilders know what they are doing.
They use steel so it's fair to say that steel is a good material to use in terms of cost versus practicality.
SO it's not unreasonable to conclude tat your system, which is quite like a ship, will have a cost comparable with a ship of the same displacement.

I have asked several times what you could do to make it significantly cheaper than a ship of that size. You don't seem to have offered any answer to that.
So, it seems that you must agree that the cost estimate is not absurdly wrong.

However that means that, if someone built your system they could sell it for the scrap value.
That value is rather more than £2.4M. Probably one or two orders of magnitude more.
So they could sell it for scrap, buy the wind turbines, sell the same power back to the grid for the same  money and pocket a huge sum of money.

Let me know which of my assumptions you feel is actually unreasonable, rather than just pointing out that they are assumptions. I know they are not cast in stone, but the point is that they only need to be very roughly correct to show that your system will fail to cover its cost.

 

Offline Geezer

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« Reply #132 on: 06/11/2011 01:29:43 »

Generator work done = Pontoon work done = Storage Vessel work done.



IMHO, that's a dangerous way to look at it, and it can easiliy lead to confusion, QED.

It should be;

Tide work done = all lost energy + captured energy.

The tide is the source of the energy, not the pontoon.

You're leaning against an open door here - my point is that it works out all ways around, the only question mark relates to the system efficiency. Turbines and generators can work very efficiently if correctly matched to the application and this should be the main input for a well designed system. It is more difficult to establish the overall system efficiency. This will be a function of the the pulley system, the additional buoyancy needed to drive the ascent phase, allowances for coral growth etc, trimming losses (governing swell,) cable stretch, Pontoon sinkage, down time for maintenance / unsuitable operating conditions.... 

Your pontoons are capable of producing 588.6MJ in 24 hours which means your efficiency is 44.1%

How does that strike you?


Without trying to second guess your calculations did you take into account my comment:

'Therefore, there is scope to engineer an arrangement such that both Storage Vessels operate from one Pontoon, which carries a number of operational and financial advantages.'


Yes, I did. As you didn't specify its displacement, I assumed it was twice the displacement of the two smaller ones. If you knew it was possible to generate the power output with half the total displacement, I would have thought you would have made that clear.

My calculation was simply the energy output over the maximum energy input based on the displacements and the tide.
 

Offline Mootle

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« Reply #133 on: 06/11/2011 18:39:59 »
This isn't a POV, it's a fact.
I can get the same nominal electricity generating potential as your machine for something like £2.4M

It's also renewable power, so it would presumably get the same FIT. (Granted that is a POV, but I think it's a reasonable one.)
So, unless you can build your scheme for less than that sum your system isn't financially viable.

It's also a fact that your rig needs a big pontoon.
It's a reasonable POV to say that it's in many ways similar to a ship. The stresses on it are different, but comparable (actually they are probably more difficult to manage).

It's not an unreasonable POV that shipbuilders know what they are doing.
They use steel so it's fair to say that steel is a good material to use in terms of cost versus practicality.
SO it's not unreasonable to conclude tat your system, which is quite like a ship, will have a cost comparable with a ship of the same displacement.

I have asked several times what you could do to make it significantly cheaper than a ship of that size. You don't seem to have offered any answer to that.
So, it seems that you must agree that the cost estimate is not absurdly wrong.

However that means that, if someone built your system they could sell it for the scrap value.
That value is rather more than £2.4M. Probably one or two orders of magnitude more.
So they could sell it for scrap, buy the wind turbines, sell the same power back to the grid for the same  money and pocket a huge sum of money.

Let me know which of my assumptions you feel is actually unreasonable, rather than just pointing out that they are assumptions. I know they are not cast in stone, but the point is that they only need to be very roughly correct to show that your system will fail to cover its cost.

For the umpteenth time, I do not think it's a good idea to make an estimate until a design has been done. I have offered various answers to your questions that seem perfectly reasonable to me but you have chosen to disregard them.

I fail to see how you can offer up the comparison with any kind of seriousness. It is so flawed that it isn't worth consideration even if you did include things like installation and whether it could actually provide load when you need it.

Perhaps we should all purchase a domestic petrol powered generator rather than invest in our energy infrastructure since those power stations would probably represent poor value for money by comparison. 
« Last Edit: 06/11/2011 18:41:45 by Mootle »
 

Offline Mootle

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« Reply #134 on: 06/11/2011 18:50:33 »
Yes, I did. As you didn't specify its displacement, I assumed it was twice the displacement of the two smaller ones. If you knew it was possible to generate the power output with half the total displacement, I would have thought you would have made that clear.

My calculation was simply the energy output over the maximum energy input based on the displacements and the tide.

I thought I did (3rd time lucky):
'Therefore, there is scope to engineer an arrangement such that both Storage Vessels operate from one Pontoon, which carries a number of operational and financial advantages.'

If you show your workings I can review further. The problem I have is that even when you are presented with irrefutable evidence you still don't concede points so I have no intention of trying to second guess what you have calculated.
 

Offline Geezer

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« Reply #135 on: 06/11/2011 19:47:53 »
Yes, I did. As you didn't specify its displacement, I assumed it was twice the displacement of the two smaller ones. If you knew it was possible to generate the power output with half the total displacement, I would have thought you would have made that clear.

My calculation was simply the energy output over the maximum energy input based on the displacements and the tide.

I thought I did (3rd time lucky):
'Therefore, there is scope to engineer an arrangement such that both Storage Vessels operate from one Pontoon, which carries a number of operational and financial advantages.'

If you show your workings I can review further. The problem I have is that even when you are presented with irrefutable evidence you still don't concede points so I have no intention of trying to second guess what you have calculated.

OK - here you go.

Quote
Based on a 25:1 gearing ratio each Pontoon volume would be ca. 7,500m3
Tidal range is assumed as 2m.

Total displacement 2 x 7500 = 15,000m3, or 15,000,000kg (ignoring the salt in the water)
Therefore, max force is 147.2MN
Max work in 24 hours is 147.2 x 4 = 588.6MJ = 588,600kJ
Max work per second is 588,600/86,400 = 6.81kJ
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%

(Or are you assuming one of the pontoons is going to spring a leak and sink?)
« Last Edit: 06/11/2011 20:00:56 by Geezer »
 

Offline Bored chemist

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« Reply #136 on: 06/11/2011 20:58:43 »
OK, so I first asked "What developments would you put on your "wish list" that would actually make your system anything other than a white elephant?"
here
http://www.thenakedscientists.com/forum/index.php?topic=41578.msg370908#msg370908
Your reply was "there are various aspects of this application that we haven't touched on that would require development. "

So again I asked
"Clearly, to make your idea work there has to be a major change somewhere and that change has to make your system a lot cheaper.

What do you think can make it work?"
And I repeated essentially the same question
"It's still not going to work unless there's some magic change in the economics so I'd still like to see Mootle's answer to my question.
What can you change to make this idea work?"

And you said this
"As I've said before there are many developmental steps required.

I agree, steel prices are only likely to go up with time (as energy costs soar). This is one reason for aiming to minimise the use of steel in the system design.

One of the biggest challenges will be the anchorage. I don't think the use of large quantities of concrete will be sustainable or cost effective. I'm working on a construction animation to show the sequences involved and would post this in due course - house rules permitting"

So you say you won't use steel because it's expensive. It is however in practical terms quite cheap. That's why shipbuilders use it.

And you say you won't use concrete for the footings.
Good luck finding anything strong enough, heavy enough and cheaper than concrete.
So, thus far you have yet to really answer the question. YOu have made a couple of questionable comments about what you won't do (i.e. use steel or concrete), but nothing about what you will do.

This suggestion "I'm researching the possibility of reinforced plastics for the main base." was kicked into touch by Geezer when he pointed out that it's going to need to be very strong. Anyway I don't think reinforced plastics are much cheaper than steel if you actually need much strength.


And you don't seem to have addressed the issue of tying the pulleys down.
"Seriously, if they still use concrete for building things like the Thames Barrier, why do you think plastic might be better?
Do you think they are idiots?"

You don't seem to have replied to that. What you next said on the subject (unless I missed something was
"I've set out why the the reused value of 7 large tankers is not a useful representation of the cost of the pontoon. "
which is unfortunate since, so far as I can see, you didn't (though you did say you had deleted a post- perhaps it was there that you explained why your big strong floaty thing would be cheaper than someone else's design of big strong floaty thing.)

Again you say things like "I don't plan to use a traditional anchor. " without saying what you will use and ignoring the fact that traditional anchors wouldn't have got  to be traditional if they didn't work.

So, once again I asked " Fair enough, but can you (as I have asked before) come up with some explanation of why you feel that you will be able to make this cheaper than, for example, a scarp supertanker?"

And your reply was "Whilst it is interesting to get 'points of view' it does get a little tiresome going over the same points."
You don't seem to have understood that the way to avoid the tiresome repetition of a question is simply to answer it. Saying "this is a new idea so anchorage for such a development would need an innovative approach." doesn't actually tell us anything.

So, once again I asked
"How are you going to make your system ten times cheaper than the scrap value of the pontoon?"

And what do I get in reply?
I get this " I have offered various answers to your questions that seem perfectly reasonable to me but you have chosen to disregard them. "

Well, they may seem reasonable to you but from my point of view they seem to lack a fairly fundamental aspect.
You still haven't said what you are going to do to make this work for about 100 times less than the scrap value of the pontoon.

This is a science website.
People who put forward ideas are expected to answer questions asked about those ideas.

If I have missed an answer of the form "I will do (whatever) which is cheaper than using an old oil tanker" then please point it out to me
I'm not going to accept an answer that says "I haven't costed it yet" because that's the whole point; several of us have costed it and it's preposterously expensive.
I'm also not going to accept an answer that says "I will sprinkle magic pixie dust on the cost and make it go away" or, the roughly equivalent " I will need to do some research in reinforced plastics" or "I won't use a traditional anchor".

Now I challenge you to answer the question in a straightforward manner or leave.

How will you make this rig cheap enough that the revenue will, at least, service the loan for building it?









 

johan_M

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« Reply #137 on: 08/11/2011 20:43:01 »
Quote
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%
I have'nt followed the whole thread, it's a bit convoluted. Please explain this efficiency part?
« Last Edit: 08/11/2011 20:50:51 by johan_M »
 

Offline Geezer

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« Reply #138 on: 08/11/2011 21:15:08 »
Quote
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%
I have'nt followed the whole thread, it's a bit convoluted. Please explain this efficiency part?

Which part of it do you not understand?
 

Offline damocles

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« Reply #139 on: 08/11/2011 23:19:20 »
Quote
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%
I have'nt followed the whole thread, it's a bit convoluted. Please explain this efficiency part?


Which part of it do you not understand?

Is it possible that the missing link is "efficiency = power out/power in" ?
 

Offline Geezer

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« Reply #140 on: 08/11/2011 23:57:38 »
Quote
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%
I have'nt followed the whole thread, it's a bit convoluted. Please explain this efficiency part?


Which part of it do you not understand?

Is it possible that the missing link is "efficiency = power out/power in" ?


It's actually a bit more complicated  :D

All the power never actually "went in". The system has the potential of acquiring a lot more energy from the tide than it outputs, so it's more a measure of volumetric, or displacement, efficiency.

The trouble with efficiencies is they can refer to lots of different measurements. If you ever want to start a really heated argument in a pub, efficiency is a good way to do it (it's usually a good idea to leave shortly after you start the argument ;D)
 

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« Reply #141 on: 09/11/2011 00:41:49 »
What do you mean by displacement efficiency? Where does the lost energy go?can you give a simple example?
 

Offline Geezer

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« Reply #142 on: 09/11/2011 04:01:16 »
What do you mean by displacement efficiency? Where does the lost energy go?can you give a simple example?

There is no lost energy (well, there will be some due to parasitic losses like friction etc.) but this measurement is not about energy efficiency. We're evaluating the efficient use of the volume of the pontoon (which is a good thing to do because the pontoon is a very expensive part of the system.)

Based on the total possible energy in versus actual energy out, the pontoons might only be half the size (to displace the required amount of water), hence an efficiency of less than 50%. This also tells us that the pontoons are probably twice as expensive as they need to be.

The thing about efficiency is that it can refer to all sorts of things, not just energy.
 

Offline Mootle

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« Reply #143 on: 11/11/2011 20:26:17 »
Yes, I did. As you didn't specify its displacement, I assumed it was twice the displacement of the two smaller ones. If you knew it was possible to generate the power output with half the total displacement, I would have thought you would have made that clear.

My calculation was simply the energy output over the maximum energy input based on the displacements and the tide.

I thought I did (3rd time lucky):
'Therefore, there is scope to engineer an arrangement such that both Storage Vessels operate from one Pontoon, which carries a number of operational and financial advantages.'

If you show your workings I can review further. The problem I have is that even when you are presented with irrefutable evidence you still don't concede points so I have no intention of trying to second guess what you have calculated.

OK - here you go.

Quote
Based on a 25:1 gearing ratio each Pontoon volume would be ca. 7,500m3
Tidal range is assumed as 2m.

Total displacement 2 x 7500 = 15,000m3, or 15,000,000kg (ignoring the salt in the water)
Therefore, max force is 147.2MN
Max work in 24 hours is 147.2 x 4 = 588.6MJ = 588,600kJ
Max work per second is 588,600/86,400 = 6.81kJ
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%

(Or are you assuming one of the pontoons is going to spring a leak and sink?)

Ok, thanks for this. The idea that I was trying to get across was that (2) buoyancy engines working on this cycle would be able to share a single Pontoon owing to the sequencing of the loading of the Pontoon. This wouldn't be the optimum efficiency in terms of revenue generation for the system but it might be useful to suit certain demand profiles. The combined Pontoon would need to have an increased volume over (1) 7,500m3, maybe 10,000 - 12,000m3 would be possible with the main factor being distribution of stresses vs VfM. This would be subject to a detailed scaled design but since I haven't got the luxury of a design team behind me I will stick to the unitary system for now.

There are too many unknown variables at this point but I would anticipate that compared with other renewable energy systems the seasonal efficiency of a working system will be quite impressive.
 

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« Reply #144 on: 11/11/2011 20:38:42 »
Now I challenge you to answer the question in a straightforward manner or leave.

How will you make this rig cheap enough that the revenue will, at least, service the loan for building it?

As I've said (more than once,) I'm not ready to properly present and fully answer your question at this particular moment.

Once I've developed the Scaled and Construction Animation sufficiently I will return.
 

Offline Geezer

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« Reply #145 on: 12/11/2011 01:50:03 »
Yes, I did. As you didn't specify its displacement, I assumed it was twice the displacement of the two smaller ones. If you knew it was possible to generate the power output with half the total displacement, I would have thought you would have made that clear.

My calculation was simply the energy output over the maximum energy input based on the displacements and the tide.

I thought I did (3rd time lucky):
'Therefore, there is scope to engineer an arrangement such that both Storage Vessels operate from one Pontoon, which carries a number of operational and financial advantages.'

If you show your workings I can review further. The problem I have is that even when you are presented with irrefutable evidence you still don't concede points so I have no intention of trying to second guess what you have calculated.

OK - here you go.

Quote
Based on a 25:1 gearing ratio each Pontoon volume would be ca. 7,500m3
Tidal range is assumed as 2m.

Total displacement 2 x 7500 = 15,000m3, or 15,000,000kg (ignoring the salt in the water)
Therefore, max force is 147.2MN
Max work in 24 hours is 147.2 x 4 = 588.6MJ = 588,600kJ
Max work per second is 588,600/86,400 = 6.81kJ
Max power in = 6.81 kW
Power out = 3.0kw
Efficiency = 44.1%

(Or are you assuming one of the pontoons is going to spring a leak and sink?)

Ok, thanks for this. The idea that I was trying to get across was that (2) buoyancy engines working on this cycle would be able to share a single Pontoon owing to the sequencing of the loading of the Pontoon. This wouldn't be the optimum efficiency in terms of revenue generation for the system but it might be useful to suit certain demand profiles. The combined Pontoon would need to have an increased volume over (1) 7,500m3, maybe 10,000 - 12,000m3 would be possible with the main factor being distribution of stresses vs VfM. This would be subject to a detailed scaled design but since I haven't got the luxury of a design team behind me I will stick to the unitary system for now.

There are too many unknown variables at this point but I would anticipate that compared with other renewable energy systems the seasonal efficiency of a working system will be quite impressive.

Yes, I figured it was something like that.

BTW, I think you really need to worry about the 25:1 pulley speed up ratio. I'm pretty sure there will be so much friction that that pontoon will not be able to exert sufficient force on the storage vessel to move it.

In practice, even with a lot of anti-friction bearings (and super-flexible cable) I think you will discover there is no way around it. A small model of that part of the system might be a good investment.

An even cheaper method would be to get a 25:1 gear setup and try to run it in speed-up mode. If you have really good bearings, the output might actually rotate 25 times faster than the input under no load (although it's also possible the gears will strip before it turns at all), but as soon as you put any load on it, it will very likely wedge.   
 

Offline Bored chemist

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Will this buoyancy engine-based generator work?
« Reply #146 on: 12/11/2011 16:12:56 »
Now I challenge you to answer the question in a straightforward manner or leave.

How will you make this rig cheap enough that the revenue will, at least, service the loan for building it?

As I've said (more than once,) I'm not ready to properly present and fully answer your question at this particular moment.

Once I've developed the Scaled and Construction Animation sufficiently I will return.

An animation will not make it cheaper,
You could answer the question without that trouble.
You have mentioned a few things you will not do, but not what you will do instead.

I think you have absolutely no idea how you are going to make this idea economically viable.
 

Offline Mootle

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« Reply #147 on: 13/11/2011 10:57:16 »
Now I challenge you to answer the question in a straightforward manner or leave.

How will you make this rig cheap enough that the revenue will, at least, service the loan for building it?

As I've said (more than once,) I'm not ready to properly present and fully answer your question at this particular moment.

Once I've developed the Scaled and Construction Animation sufficiently I will return.

An animation will not make it cheaper,
You could answer the question without that trouble.
You have mentioned a few things you will not do, but not what you will do instead.

I think you have absolutely no idea how you are going to make this idea economically viable.

The idea of this thread was to see if the system would work in principle.

Your speculations as to what ideas are in my head are noted but as the authority in this respect I assure you that you are wrong. I'm aware of the difficult challenges but have a number of innovative solutions in mind. Exploring these lines takes time but until the design is fixed the cost of the system is nothing more than a known unknown. This thread has reinforced a need to improve the available revenue and I'm satisfied that with a sensible balance of technologies I will have a reasonable shot at value engineering a solution which provides a reasonable business case.

Once I've developed my theorem to a point at which I'm ready to present I will return if that's OK.

Thank you for your patience.
 

Offline Mootle

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Will this buoyancy engine-based generator work?
« Reply #148 on: 13/11/2011 11:19:43 »
Yes, I figured it was something like that.

BTW, I think you really need to worry about the 25:1 pulley speed up ratio. I'm pretty sure there will be so much friction that that pontoon will not be able to exert sufficient force on the storage vessel to move it.

In practice, even with a lot of anti-friction bearings (and super-flexible cable) I think you will discover there is no way around it. A small model of that part of the system might be a good investment.

An even cheaper method would be to get a 25:1 gear setup and try to run it in speed-up mode. If you have really good bearings, the output might actually rotate 25 times faster than the input under no load (although it's also possible the gears will strip before it turns at all), but as soon as you put any load on it, it will very likely wedge.  

Pulley's are still my preferred option as I haven't worked out how to make a gearbox solution work for this application but I'm still mulling that one over.

I've recognised the need to maintain load and this would be achieved by not allowing the Storage Vessel to break the surface following the Ascent phase, as stated on the audio of the Schematic animation. However, I acknowledge this isn't what's shown so apologies for the misunderstanding.

I agree that a lower ratio would be easier from an engineering perspective. The 25:1 ratio is a target driven by revenue optimisation. A pilot scheme is the next step but before I would look for scheme funding I need to be sure that there is a business case. If I can demonstrate a business case I would look to enter into consultation with specialists for a number of elements of the design where I'm not a practitioner. The pulley system would be one such area.
 

Offline Geezer

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Will this buoyancy engine-based generator work?
« Reply #149 on: 13/11/2011 23:52:45 »
Yes, I figured it was something like that.

BTW, I think you really need to worry about the 25:1 pulley speed up ratio. I'm pretty sure there will be so much friction that that pontoon will not be able to exert sufficient force on the storage vessel to move it.

In practice, even with a lot of anti-friction bearings (and super-flexible cable) I think you will discover there is no way around it. A small model of that part of the system might be a good investment.

An even cheaper method would be to get a 25:1 gear setup and try to run it in speed-up mode. If you have really good bearings, the output might actually rotate 25 times faster than the input under no load (although it's also possible the gears will strip before it turns at all), but as soon as you put any load on it, it will very likely wedge.  

Pulley's are still my preferred option as I haven't worked out how to make a gearbox solution work for this application but I'm still mulling that one over.

I've recognised the need to maintain load and this would be achieved by not allowing the Storage Vessel to break the surface following the Ascent phase, as stated on the audio of the Schematic animation. However, I acknowledge this isn't what's shown so apologies for the misunderstanding.

I agree that a lower ratio would be easier from an engineering perspective. The 25:1 ratio is a target driven by revenue optimisation. A pilot scheme is the next step but before I would look for scheme funding I need to be sure that there is a business case. If I can demonstrate a business case I would look to enter into consultation with specialists for a number of elements of the design where I'm not a practitioner. The pulley system would be one such area.

Er, well, you might want to take a squint at this before you go much further, particularly the term that shows that the efficiency is related to the inverse of a value raised to the power of the number of sheaves. 25:1 is going to need a lot of sheaves. 

http://en.wikipedia.org/wiki/Block_and_tackle#Friction
 

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Will this buoyancy engine-based generator work?
« Reply #149 on: 13/11/2011 23:52:45 »

 

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