Talk:Severn Barrage

Other barrage projects
Please add older projects, by year.

Also, the details of the STPG plans are all in those links. Expand on them with generic pictures...I will if I ever get time! Fig 13:57, 31 March 2006 (UTC)

I have now added some pics Fig 13:23, 8 June 2006 (UTC)

I've added some brief details of the older projects, and the new one by the guy from neath. Also added supporters and opponents of the plans. Fig 18:46, 5 September 2006 (UTC)

Bias?
This article is clearly written by the pro-barrage lobby and therefore breaks Wilkipedia's NPOV policy. In particular, the environmental costs, and degree of acceptance in the scientific community of the costs, are understated. Suggest removal of article or wait until a truly unbiased submission is made 212.137.61.82 10:47, 29 August 2006 (UTC)


 * You must be having a laugh! Which bits do you think are NPOV? The advantages and disadvantages are both well debated and referenced, including those of Friends of the Earth. The environmental costs are well noted and discussed, and are compared to the costs of not building the barrage - which would be further nuclear reactors at Hinckley Point, Berkley and Oldbury power stations. Engineering community has assessed the costs several times (as part of STPG and other investigations, which will hopefully be expanded in this article by someone) and the £10-15 billion tag is fairly sound. If you have specific objections, lets see them. Fig 17:27, 29 August 2006 (UTC)


 * While I have no defined opinion on the project per se, I do agree that some parts would need rephrasing. As an example, this one is a conclusion (i.e. Original Research) put in Wikipedia's institutional voice:

"However, in order to understand where the vested interests might lie, it is necessary to see the wider picture. The alternative to any Severn Barrage would probably be three nuclear power stations; and these are huge facilities that would have to be built by someone - the same construction industry that stands to gain from the barrage."
 * Regards, -- Asterion talk 10:18, 25 February 2007 (UTC)


 * I agree that there seems to be a strong perception toward a bias for this barrage by one person in particular. Because Friends of the Earth are in favour is NOT justification when they also support other types of renewables. Debate over costs also does not change the perception of bias if the issues challenged in the debate are not included. If costs are high then it is less likely that the project would proceed. For example 15 billion for 2000-8000 megawatts (if these estimates are correct as they have not been produced here for scrutiny) could be considered insane and not reason to give the go decision. Comparing nukes to renewables is a very poor example of a comparison and is not comparing apples to apples. The nearest competeing technology is tidal stream which is a far better comparison and is more cost efficient per megawatt. As for engineers there is nothing they love more then to suck up money doing estimates on far fetched projects. The specific objections are then the environment, whether any EPA (Environmental Protection Authority) anywhere would permit the total disregard to the environment that a barrage would entail. Costs, whether the exercise would become a white elephant ever able to justify the huge civil costs not to mention the added cost of the disruption to the transport industry. Competing technologies such as tidal stream have a bigger bang for your buck then barrages. Companies like MCT a local UK company has developed and deployed a tidal stream turbine that could easily be deployed in the Severn region for a fraction of the overall cost of building a barrage kieeping the tree huggers happy and satisfying the need for an energy hungry nation.

Why then would this project proceed?Tidalenergy 05:05, 3 October 2007 (UTC)


 * Tidalenergy, I see that not content with driving me from the Tidal power page with your endless and creepily obsessive sniping at me you have decided to follow me here. If you continue to fire abuse at me in on this page and distort everything I write in the way that you did previously I shall report you to the arbitration committee. There is no need for you to behave in the way you did on that page just because you could not get consensus for your edits.


 * Your promotion of your former company Tidal Energy Inc's products ("Shrouded turbines") is well known and has been noted by many other editors other than myself. Indeed, I was not the first editor to report your for Conflict of Interest. And for the record, I did not "get you blocked". Again, I was just one of the many editors who put warnings on your page for vandalism, and I was not the editor who instigated your block (I dont have that power). I know it suits you to pretend that I did all these things against you, but it is simply not true.


 * In response to your points, why dont you read the UK government's Sustainable Development Commission report, which you quite obviously havent yet . And why dont you read the DTI's report on the barrage, which you quite obviously havent yet . Fig 09:39, 3 October 2007 (UTC)

Sorry old man this is not the Twilight Zone and I have no intention of creepily obsessively sniping at you. Perhaps you might want to tone down the allegations.


 * Perhaps if you didnt follow me across Wikipedia pages to do perpetual battle with me I wouldnt be so paranoid. Fig 10:11, 4 October 2007 (UTC)

I would invite you to please take up the option of mediation/arbitration --- I long ago offered this but you never took it up. I would gladly submit to any fair and equitable conflict resolution in an attempt to have you relieved of what you perceive as persecution. Perception IS reality as they say.

As for the other allegations I have answered you before --- I have no former company that I am promoting, believe it or not.


 * Tidalenergy, your former company Tidalenergy is a producer of "Shrouded Turbine" tidal stream devices. This is well known and was noted by others during your original COI dispute. You claim you are not promoting them, yet you continue to add their activities and products to the Tidal power page. People are not stupid. Fig 10:11, 4 October 2007 (UTC)

In regard to the data, if it is fair for you to ask that the evidence be produced here, when you ask for it from others - why is it not fair to ask you the same? Not everyone has access to your vast array of data bases. Please, I say this without malice or guile, can you post it here for all to see? Let the debate be open fair and transparent. Tidalenergy 21:24, 3 October 2007 (UTC)


 * Did I mention that you should read the Government's Department of Trade and Industry Report (here ) and the Government's Sustainable Development Commission Report (here )? Sorry, I just wasnt sure if I had said that to you already...was it 10 or 15 times?

ENERGY PRODUCED
A lot has been said of the amount of power that would be produced - around 2000-8000 megawatts - but with little if any scrutiny of these numbers. The numbers and the studies should be produced here to add to the debate and allow scrutiny. Tidalenergy 05:14, 3 October 2007 (UTC)


 * Read the DTI report . Fig 09:40, 3 October 2007 (UTC)


 * My question is ... Can you please present it here? Not everyone has access to these as you obviously do. Tidalenergy 21:27, 3 October 2007 (UTC)


 * Did I mention that you should read the Government's Department of Trade and Industry Report (here ) and the Government's Sustainable Development Commission Report (here )? Sorry, I just wasnt sure if I had said that to you already, was it 10 or 15 times? Fig 10:12, 4 October 2007 (UTC)

Environmental Impact
Any Severn Barrage proposal needs to consider 1) Impact on European protected species and habitats. You cannot replace an ecosystem like the Severn. The site is designated for what is there now, not what might emerge after the works are finished. You cannot mitigate for destruction. 2) Where will the building materials come from? Do we want to hollow out the Mendip Hills just to drop them in the river? 3) Water levels are likely to rise inside and outside the barrage requiring considerable investment in flood protection. This is because the flow of the water in and out of the estuary will be constricted and slowed so the water will back up thus raising water levels. 4) The impact on the viability of Bristol Port needs to be considered. 5) Many of the factories alongside the Severn eg Avonmouth discharge effluent into the river. The Environment Agency have guaged and licenced these discharges against the current very active tidal regime. Any change to that regime will inevitably lead to a reassessment of those discharges potentially impacting negatively on the viability of those works.


 * Both the STPG proposal and the Shoots Tidal Barrage proposal obviously did these things or they wouldnt have been taken seriously by government - and the results are in their documents. Are you saying that you think these things should be discussed in the wiki page? If so, they can be "lifted" out of the documentation; the only problem I have with that is that they are very complex issues and would make the page huge - isnt it better to refer people to the documents themselves to read all that? Fig 10:17, 2 November 2006 (UTC)


 * You claim that these justify your argument but are unable to be produced AND if they are would be difficult to be understood due to the complex nature of the issues. This is not a clear reference to the project going ahead.If the issues are complex then the project is by virtue of the complex issues leslikely to proceed as these complex issues need to be addressed. I for one have not seen the document and find it a cop out that difficulties with lifting it and complex issues only restrain the debate and do not support your comments. In a free and fair discussion ALL the facts should be produced. Saying you don't have time to do so is lame when you seem to have plenty of energy to support your opinions. The old saying put up or shut up comes to mind. Tidalenergy 05:23, 3 October 2007 (UTC)

The article contains a factual error - the severn estuary is not designated as a special area for (sic) conservation (SAC) under the Habitats Directive but part of the estuary is designated as a Special Protection Area (SPA) under the Birds Directive and is also an internationally designated site under the Ramsar convention. The UK government is currently considering whether to put the site forward as a potential special area of conservation (SAC) but has yet to do so. (81.179.104.197 19:05, 7 June 2007 (UTC))


 * Good point and goes along with my points above about how one person with a handful of broad based information is dominating the debate, misquoting evidence and misleading the debate. Tidalenergy 05:23, 3 October 2007 (UTC)

Severn tidal lagoons
Could you provide a source for "The output of a set of large lagoons has been estimated at about 500 MW peak output, less than 1/10th of a barrage." My reading of the reference provided is that for the largest scenario peak output is about half of barrage peak (4.5GW), with average power 30% higher than barrage because it operates in more states of the tide. Also why was "it is claimed that" added to "the lagoons would not impound water in the ecologically sensitive inter-tidal areas of the estuary."? My reading is that the lagoons would be built below the low-water mark, not over the inter-tidal areas. Rwendland 12:51, 25 January 2007 (UTC)


 * The figure of 500 MW peak output comes from a day symposium "Extracting Power from the Severn Estuary" organised by Gloucester Country Council in 2006. There obviously isn’t an easy way to link to the information that was presented at the symposium. Friends of the Earth - despite the great work they do on the environment - are not hydrodynamic engineers, and the numbers they come up with have to be taken with a pinch of salt, especially as their lagoon document contains several basic errors that have allowed them to inflate the energy production. I trust FoE to tell me about declining numbers of sparrows and species migration due to global warming, and I trust IEE/ICE to tell me about power output of various configurations of turbines; but not vice versa!


 * One error in the FoE document is that of splitting the lagoons into partitions in order to spread power generation. No sane designer does this. FoE have not realised that by doing this you immediately lose over 50% of your generation ability, because your exhaust water quickly fills up the other reservoir. The theoretical maximum power is already only 50% because water stops flowing when the two reservoirs are both equally 50% full; however, practical power stops well before then because the head (height difference) is already unusably low when perhaps only 40% of the water has flowed. Quite apart from that, the fact that one reservoir (1/3 of the total) must remain empty during tidal refilling loses you another 33%.


 * Another error in the FoE document is that it is simply announced that pumping would be used in both directions. This is because FoE misunderstand what pumping is about. FoE have assumed that all the proposed barrages use power generation only on the ebb tide because of some stupid design flaw. However, using the ebb tide allows pumping to increase the head (water height difference) before the water is released. FoE realise that this is useful and appear to know that power output is proportional to the square of the head. Hence, a pumped single direction flow can produce the same power as an un-pumped bi-direction flow if the head is increased by just 40%. Having single direction flow has other advantages that make it more attractive. But...Pumping cant be used in both directions, because there isn’t enough time to drain a pumped reservoir before the tide starts coming back in again. FoE don’t seem to understand this, and so simply double up their power output by announcing that theirs would generate in both directions with pumping.


 * FoE claim they would impound 60% of the water area of the barrage. The need to do this, in shallows, out of the shipping lane, on areas of sound foundation. Unfortunately, there isn’t an abundance of easy sites, without using the obvious intertidal areas. Therefore, their "claim" must remain a claim until they produce maps showing where the lagoons would go; which they have currently refused to do for some reason.


 * I wish the FoE lagoons proposals were realistic, believe me I do. But until they come up with the open calculations of how they get to their power outputs, and maps showing how they will overcome the raised objections, their plans need to be linked to in the article but cant be taken as encyclopaedic. Fig 20:49, 25 January 2007 (UTC)


 * I've found a very negative DTI engineering study on the smaller Swansea Bay tidal lagoon scheme, and having read that I'm pretty dubious about the economics of the concept now. But having said that, Wikipedia is about verifiability more than correctness - we really need to find a checkable source for negative statements in the article.


 * On bi-directional pumping, while it is less efficient at extracting energy, it has other significant advantages - and it seems the Barrage people are considering the possibility. The National Grid and other suppliers would struggle to absorb a periodic 8.6GW supply efficiently (~20% of UK supply), so price would be low; 3GW for twice as long might make more money. And 3GW max would save significant costs on National Grid reinforcement to distribute the supply. Rwendland


 * Good links Rwendland. Interesting that they might consider a lower power scheme that raised more revenue because of pricing bands. Actually, it's a shame really, because it means the Severn would be less efficiently exploited simply because of the present electricity pricing regime.


 * You are correct on Grid reinforcement though. It would be nice if some hydrogen technology was invented soon that could absorb the excess power during peak and use it usefully in some way.


 * Ullman is also in error to claim that the barrage would be taxpayer funded. It would be funded privately in exactly the same way as lagoons would be. Perhaps he hasnt noticed that the CEGB was privatised in the early 90's? It's elementary errors and misinformation like these that make it hard to take the lagoon promoters very seriously. I also find it bizarre that lagoon supporters say they are great because they will create new habitats, and then attack the barrage for doing exactly the same...


 * PS I have changed your gigabytes to gigawatts ;-) Fig 00:24, 26 January 2007 (UTC)

As an exercise I have used their given numbers (page 2 of their document) for wall length and impounded area to calculate the number and size of lagoons they envisage, to highlight why simply stating that the lagoons will be "at the low water mark, typically up to a mile out from firm ground" is not credible without showing exactly where.

(These sums are easy using simultaneous equations of the circumference and area of a circle.)

FoE intend to impound 115 miles^2 of water. As a single lagoon this would be an impossible 12 miles in diameter, for which there is obviously no suitable site. However, equalising this with the stated wall length of 95 miles, shows that they are intending to use 20 lagoons of diameter 1.5 miles. I’m not sure whether FoE included the internal lagoon dividing walls in their sums. Doing so increases the amount of wall by 2/3 for the same amount of water impounded, and forces the size of the lagoon up; it then requires 12 lagoons of diameter 2.6 miles to make the sums balance (this is an approximation, because the internal walls are stated as being "less substantial"). As noted above, these need to be in the shallows, out of the shipping lanes, on areas of sound foundation; and that doesn’t leave many locations at all in the Severn Estuary.

I think part of the lowness of the externally estimated 500 MW peak output for lagoons comes from correcting the FoE assumptions about pumping, bi-directional generation, and efficiency in multi-celled lagoons; and part comes from lowering the likely number of lagoons and impounded water due to lack of enough suitable sites.

Finally, FoE need to clear up their construction methods. They correctly point to seabed aggregate dredging as the only likely source for the astonishingly big 200 million tons of aggregate needed (page 9); but seem to have forgotten that they are themselves opposed to seabed aggregate dredging, e.g. Fig 10:29, 26 January 2007 (UTC)

Public or private funding
It is interesting to note that the project is to be funded by private investors not the UK government as has been stated time and again by one person.....There is one fact that is a constant in the universe even Stephen Hawkins would agree to, investors are a queer animal that wish to see return on their investment. Given there are very large question marks over the amount of power produced (numbers vary from study to study) a investor would look at this propsal as not commercially viable when there are easier and less risky venture about. If this is not going to be built by government an outlay of 15 billion for 2000-8000 meg or 2-6 meg per million does not hold attraction for private investment.Tidalenergy 05:30, 3 October 2007 (UTC)


 * As is perfectly clear from the text, the investigation costing several million pounds is to be funded by the Government; the construction costing several billion pounds would be funded by the private sector. I have never said or implied that the Government would fund the construction. Fig 09:43, 3 October 2007 (UTC)


 * That's not what the SDC report says, it's quite clear: "the conclusion from this comparison is that both Severn barrage options are unlikely to be economically viable for private sector investment in electricity generation." (page 118) At commercial discount rates (8% to 12% range) electricity cost would be hopelessly uneconomic (8.5p to ~17p/kwh), even after CO2 pricing of competition - unless perhaps the developer was allowed to do a large amount of property development on cheap coastal farmland as a "subsidy", several new towns worth I should think. Rwendland 22:55, 3 October 2007 (UTC)


 * Isnt "publicly led and privately funded" the whole principle of PFI and PPP? This is the way things are done these days under New Labour. There is absolutely no way the government will stump up £15 billion, and the SDC know that, and knew that when they did the report. They never would have suggested it was viable and worth several millions of pounds worth of further investigation if it was all based on the assumption that the state would pay the whole lot. Fig 10:40, 4 October 2007 (UTC)


 * Eh? The SDC report does propose public ownership: "the SDC believes that a barrage should be publicly-led as a project and publicly-owned as an asset to ensure long-term sustainability in its design and delivery, and a fair allocation of risks and rewards. We believe that a publicly-led approach would be the best way to ensure against unsustainable ancillary development ... A publicly-led approach would enable the use of a low discount rate, justified by the long-term climate change benefits and potentially facilitated by the Government’s access to low cost capital." (pages 12-13) Because electricity is uneconomic at commercial discount rates, proponents really have no option but go for some kind of public funding, or large scale subsidy. The economics of the barrage are much like nuclear power, only harder; very high capital costs and a long build-time before revenue is obtained, so is highly dependent on the cost of capital. Rwendland 19:40, 4 October 2007 (UTC)


 * Rwendland, I don't disagree with any of that; what I'm saying is that I think you need to understand the PFI could still satisfy those requirements. Schools and hospitals built with private money under PFI are not "private" schools and hospitals, they are still "publicly" owned. You might want to read Private Finance Initiative and Public-private partnership. Fig 22:25, 4 October 2007 (UTC)


 * Yes, but PFI/PPP operators don't normally have access to cheap government finance, so it will work out too expensive to go forward (unless they are given extensive property development opportunities to subsidise the barrage). As the SDC says: "We do not believe it would be possible to deliver a sustainable Severn barrage through the private sector." (page 145) Rwendland 00:10, 5 October 2007 (UTC)


 * So it will be a combination of both? IMHO any investor that would invest in a project that would cost 15 billion for 2-8 gig (just exactly how much energy it would make no one seems to be able to say for sure) needs to have their head read. In a best case scenario this would equate to 2 million per megawatt. When compared to alternative (renewable technologies NOT nukes) technologies there are far better options with higher returns. In order for this to be attractive to investment it has to have a bottom line that would justify investment or no one will bother. Tidalenergy 21:33, 3 October 2007 (UTC)

With the advent of Bio-diesel there is a new advantage to tidal lagoons. The emerging data regarding the production of oil feedstocks from algae suggests yields of 95000 l/h, this means that tidal lagoons could provide an essential new source of income for farmers in the southwest growing algae in a controlled way in tidal lagoons. These lagoons would be nurished by the high silt salt-water from the estuary while at the same time providing managed saltwater marshes for natural species of the area. I think someone should consider this in more detail and add it to the wiki, I will do it myself if i have time. —Preceding unsigned comment added by 88.105.127.79 (talk) 19:08, 15 August 2008 (UTC)
 * offset the cost by creating productive tidal lagoons**

Will it pay
The Fig man has been pushing this idea all over Wiki. One needs to ask who will pay the billions to build let alone operate the system. At a cost of 10-15 billion (today --- it usually blows out to 2 or 3 times in reality) for 4.5 - 5 gigawatts it equates to around 2 - 3 million pounds per mega watt. Given a price for wholesalers into the grid of 12 pence at best (I will stand corrected on the price if someone has accurate numbers) or 120 pounds per meg or 120,000 pounds per gig then the pay back would be 10 - 15 years. This is below what private enterprise would expect as a return on investment.

Clearly government would need to provide incentives if the project were to go ahead.

Otherwise by reducing civil infrastructure, eliminating the concrete barrier and the flodding of the eco systems it seems that under water windmills arrayed across the sea floor would be capable of generating large amounts of power at a fraction of the cost. Just how much would be determined by the water velocity. But there is no reason to believe that existing companies already commercialising under water turbines could be capable of utilising the site.

Sorry Fig man but I can not see investors putting money into a utility unless it returns at least 17%. In order to make this a reality it needs money and lots of it and sad to say support form the EPA over eco issues.

Large systems like this are problematic at best and can be handled better by alternative options. (Added by User talk:210.9.237.1 on 8 Aug)

Vandalism of disadvantages
I placed a number of edits on the disadvantages that have been deleted. This should not be the case as it was fair and balanced and not a POV.Tidalenergy 12:29, 19 September 2007 (UTC)


 * As has been pointed out, these may or may not happen, but they are not disadvantages. (E.g. EIAs are good things not bad things). Also, their removal was not vandalism. Fig 19:19, 20 September 2007 (UTC)


 * I agree the points posted were not necessarily advantages or disadvantages, but some could come under the category of support or objection. A list of such items, maybe in the opinions section would add balance to the article - the job of which is to neither support no oppose the proprosed barrage. Any objection posted (or the opposite) should be backed up with an appropriate citation stating who stated it, rather than simply be one that the wiki editor feels strongly about. The same need for citations should apply to each and every advantage and disadvantage. Not one of the current advantages or disadvantages currently listed is cited, which is a major failing of the article. --Cheesy Mike 19:55, 20 September 2007 (UTC)


 * Yes, I think that's fair. Some of them were partially covered already in the text; although the issue of the long-term cost for pricing wholesale electricity from major power stations is hugely complex and beyond the scope of the article, especially as the UK market is in a state of legislative flux re "Renewables Obligations" and other credits. The closest wiki comes is Electricity market. Fig 22:26, 20 September 2007 (UTC)

Proposal with central pumped-storage ring-dam ??
Hi, can anyone provide a reference for the proposal that added a massive 'cooling tower' ring-dam pumped-storage facility to the centre of the barrage ??

IIRC, it featured in 'New Scientist', but long, long before their digital archive began...

IIRC, benefits included time-shifting tidal generation to suit demand, and being able to maintain a much more 'natural' estuary environment-- Literally, you could dial-a-tide.

Also, IIRC, by 'texturing' and 'planting' (!!) outer face of the ring-dam, it could provide a protected, sea-cliff environment for puffins and other birds.

I don't recall finances beyond the peak-load savings inherent in pump-storage, but there was a comment about central 'island' that formed the root of both barrage & ring-dam being a convenient 'aerial rope-way' distance from both shores. Apparently, that would allow economic re-supply during construction. Also, the barrage could be be generating and earning while the pumped-storage ring-dam is built to full height...

Seems too good to be true...

82.42.187.185 10:36, 1 October 2007 (UTC) Nik


 * I'm not exactly sure what you are suggesting there, but there are things that look like it in the SDC document noted below... Fig 19:39, 2 October 2007 (UTC)

Sustainable Development Commission Paper
There is a huge amount of information in the recently released Sustainable Development Commission Paper (as you might hope from an organisation that has just spent a year examining the history of the schemes!) That information should be transferred to this page to enhance it considerably. Fig 19:37, 2 October 2007 (UTC)

Disadvantages

 * Civil costs would be high (estimated at 15 billion pounds).


 * Not an issue for the public because it would be privately funded. Fig 09:47, 3 October 2007 (UTC)


 * The cost to power produced ratio would be lower then if tidal stream technologies were used (approx 3 million/MW compared to 1 million/MW).


 * Not true - read the SDC report.

The cost of the proposal is around 15 million and likly to blow out if the Government builds it. Therefore the amount of energy returned would not justify the project on a cost per Megawatt basis.

If however tidal stream technologies were to be use, in particular shrouded turbines the cost per Megawatt would be significant lower and may justify the project proceeding.Tidalenergy 04:50, 3 October 2007 (UTC)


 * There's a surprise, so if your former company's products were used everything would be just fine. Gosh. Did I mention that you should read the SDC report? . There is only a fraction of the amount of power available from tidal stream potential in the estuary. Indeed, the Severn Estuary isnt even the best place in the UK to put tidal stream devices, so it isnt a case of tidal stream OR barrage in the estuary, because stream dvices would be put elsewhere in the UK instead. Fig 09:47, 3 October 2007 (UTC)


 * I have answered your allegation/s about an alleged former company and you continue to jibe away. How about we debate the core issues here not your prejudice?


 * Your COI is a core issue in your argument. Fig 10:22, 4 October 2007 (UTC)


 * How about producing the reports here where all can see and be enlighteded not just the privileged few?


 * What, you mean these two - the Government's Department of Trade and Industry Report (here ) and the Government's Sustainable Development Commission Report (here )? These ones that I keep posting but that for some reason you wont read? Fig 10:22, 4 October 2007 (UTC)


 * So let me understand this -- you are saying that the high velocity that occurs in the Severn is not suited for tidal stream? That a barrage is the only option?


 * No, I didnt say that. Your perpetual and deliberate distortion of almost everything I write must be comical to other observers reading this. I'll repeat what I wrote just a few lines above here, for your own clarification, because you seem to have trouble here. I said "the Severn Estuary isnt even the best place in the UK to put tidal stream devices". When I wrote that, that's what I meant. Would you agree it is best to put tidal stream devices in the best locations for them? If so, then the Severn Estuary isnt it yet, until other other locations are "full", if such a state is possible. Fig 10:22, 4 October 2007 (UTC)


 * Cool. Can you please explain the other questions above? Cheers. Tidalenergy 21:40, 3 October 2007 (UTC)


 * I've done by best. I doubt it will be enough, because your ideological obsession and corporate conflict of interest make you impervious to arguments other than your own. Not content with having hounded me from the Tidal power page, you have now chased me here. I have given up trying to defend that page from your POV, good luck to the editors who remain there. But just one more time, for your own aid, why dont you read these two documents: try the Government's Department of Trade and Industry Report (here ) and the Government's Sustainable Development Commission Report (here ). I think you'll find them interesting. I've posted them before, but you seem to have missed them, for some reason. Fig 10:22, 4 October 2007 (UTC)


 * Please believe me when I say I AM saddened by your feelings of persecution. I think you are far more valuable then me. Please remain and I will vacate the field. Thanks for the links I WILL read them. Only I will keep my comments to myself. Regards Tidalenergy 11:12, 4 October 2007 (UTC)

High-Level pumped storage scheme.
Many Thanks for suggestions and links !

However, the documented pumped-storage barrage schemes seem to use low-level lagoons, not the high-level ring-dam I remember-- Think 'cooling tower'.

Perhaps the proposal was no more than that one-off article and sketch... 82.42.187.185 14:35, 13 October 2007 (UTC)

Nazi's?
The nazi's never conquered Britain... they merely bombed the heck out of it... so why is it saying that the Nazis might have thought of the Barrage...? —Preceding unsigned comment added by 58.7.72.67 (talk) 10:46, 22 October 2007 (UTC)


 * Agreed, i cant find any varification of these claims and feel it should be removed (seems like a poor attempt at slander to me). Edd17 (talk) —Preceding comment was added at 22:26, 6 March 2008 (UTC)

I have removed the Nazi section as there was no source and I could find no reference to Nazi plans to build it on google. Please put it back in if a source does exist, however the idea that the Nazis were that well prepared in their invasion plans that they were planning major construction projects is rather hard to swallow. 62.232.4.58 (talk) 08:10, 12 June 2008 (UTC)

Disadvantages: negating "green" element
I must say that I think it untrue that "Cost of build would mean the buy back time would be considerable and the barrage may only have a finite life span due to silting up behind barrage negating the "green" element" since in the Daily Telegraph it said that "It could be in operation by 2020 and the 'payback' time for carbon cost in building the barrage was only five to eight months" see —Preceding unsigned comment added by 81.109.99.228 (talk) 17:54, 2 July 2008 (UTC)


 * Agree. In fact, it's daft to say it may only have a finite life span because a) noone has ever said it would have an infinite lifespan; and b) nothing has an infinite lifespan. As for silting up, currently those opposing the barrage are trying to have it both ways. They are claiming that a) the silt will be stripped away, thereby increasing coastal erosion; and b) that everything will silt up. The reality is that most (but not all) of the suspended silt will drop out of the water when the barrage is finished, and this equates to about 12 inches of silt deposition across the estuary. What happens then is a matter for detailed computer modelling as part of the feasibility study. However, the only source of silt into the estuary once the barrage is finished would be the River Severn, and to a lesser extent the Rivers Avon and Wye. These are not major sediment rivers, by any stretch of the imagination. Fig (talk) 08:41, 3 July 2008 (UTC)

Benefits and disadvantages sections & other areas for improvement
I've been trying to improve some of the sections in this article eg combining short 1 sentence subsections in the history and adding or improving references, but I think a lot more work is needed. I arrived here as I'm working my way through the articles with cleanup tags listed at WikiProject Somerset/Cleanup listing where this article is top of the list! Some areas I would like help to work on include: I recognise this article addresses issues on which individuals hold strong views and this may have influenced its development. Although I'm still undecided on the best way forward for the barrage proposals, I do feel this is an article is an important topic which deserves to be improved.&mdash; Rod talk 12:47, 11 August 2008 (UTC)
 * expanding the lede to include something about the problems (including environmental issues) and advantages
 * updating the section on finances & economics
 * turning "Benefits and Disadvantages" from lists into prose & adding citations so that the original research & citation needed banners could be removed
 * providing reliable sources throughout
 * finish updating all references to follow Citing sources


 * I applaud you for starting this. My suggestion would be to remove the whole section, archive it here, then only reintroduce supporting or counter arguments when they can be properly substantiated e.g. with references to Friends of the Earth, local council, scientific groups etc. Obviously I'm happy to assist. Will start looking... --TimTay (talk) 13:29, 11 August 2008 (UTC)


 * Hi Rod, yes well done for the effort there. On how to take this forward, I would certainly oppose deleting the whole "Benefits and Disadvantages" section - rather the best thing is to try to find references for it. I am a bit puzzled by those that think that everything in wiki that isn't referenced should be deleted. Those of us who have been around a while remember that it was only a couple of years ago that references were seriously recommended - before that nothing had references. Its silly to simply that wikipedia should essentially be started again and everything from the pre-reference era should be lost...


 * Just an FYI that the "Benefits and disadvantages" section appears to be (nearly) verbatim from this blog. Zue Jay (talk)  02:48, 12 August 2008 (UTC)


 * That blog entry was written 6 days ago - it is quite obviously pulled from Wiki, not the other way round.Fig (talk) 08:29, 12 August 2008 (UTC)
 * Hehe. I thought of that after I wrote that comment - see here. Eh, what can I say? Chicken, egg; cart, horse? Too bad bloggers don't give a quick shout-out to their sources (aside from that image at the top - should've suspected - but like I said, just took a quick look). Zue Jay (talk)  23:57, 12 August 2008 (UTC)
 * In the absence of improvements so far, I've tagged the last two sections, Vested interests and Trans-barrage transport links which are highly debatable and OR to put it mildly. Ghmyrtle (talk) 09:34, 6 November 2008 (UTC)

Benefits and Disadvantages Unsourced
The list of benefits of this scheme is largely unsourced, while the list of disadvantages seems to have no sources at all! If these positives and negatives of the scheme are reported elsewhere, provide a verifiable citation to support them, or else remove them from the page. Original research is outlawed under WP:NOR, meaning that both lists require reliable published sources for each point made. Unsourced information is unhelpful and, given the rather tedious war that happened further up this talk page, open to abuse/bias. I myself do not know enough about this topic to correct the problems I can see with this article, but maybe someone else does. -- Matt 86.148.228.131 (talk) 02:17, 14 April 2009 (UTC)
 * I've had another go at trying to reference some of the material in this article but when I got to this section I just gave up. I'm coming to support of the radical proposal, suggested above, of removing everything which is not supported by reliable sources to remove the tags & banners which are all over this article. As it is likely to get lots of hits in the new year it really isn't a good advert for wikipedia in its current state.&mdash; Rod talk 17:25, 12 December 2009 (UTC)


 * I think that would be a shame. Most of the entries are pretty obvious and could be found in the links in the "External links" sections. The issue you are raising is not that the Benefits and Disadvantages are controversial, but simply that there are a lot of them that need referencing, which would take a couple of hours. Sadly I dont have the time to do that kind of thing these days, but it seems to me the best way to improve wikipedia is to encourage the expansion of articles rather than just deleting stuff that you dont have time to work on. Fig (talk) 12:23, 13 December 2009 (UTC)

Severn Lake
I will shortly remove this section from the article (ref commented out):
 * In 2006 Gareth Woodham, a businessman from Neath in Wales, submitted plans called "The Severn Lake" to Sedgemoor District Council in the name of Combined Innovations Ltd for a barrage from Brean Down near Weston-super-Mare, to Lavernock Point near Cardiff. According to Woodham, the barrage would feature 14 electricity generating turbines, a dual carriageway, a light railway, four marinas, and two lock gates to give ships passage. It would supply electricity for the whole of the South West, and according to Woodham it would cost about £650 million and take up to 20 years to complete.


 * However, it is not clear how Woodham's plans, which are more ambitious than those of the STPG, could be delivered for 1/20th of the cost.

To me, this seems like recentist, given that the plan's got no formal backing (it was not considered in the shortlist stage of the SEA, for example) and most sources on the subject are self-published by Woodham, or are him essentially promoting the plan in local newspapers - although coverage is particularly light, compared with other Severn Barrage plans. (One should be careful to remove references to the place in Canada if searching.) To all intensive purposes, it seems like a pipe dream, and one really needs significant coverage in third-party sources to suggest otherwise. - Jarry1250 [Humorous? Discuss.] 19:31, 8 March 2010 (UTC)


 * Agreed. Fig (talk) 00:17, 9 March 2010 (UTC)

Is It 'Renewable Energy' Question
Regarding this section: "However, there is the question of the applicability of the term 'renewable energy' to tidal power, as the root energy source is the rotational kinetic energy of the earth, which is not renewed." Isn't this a little pedantic? Surely all 'renewable energy' could be described as non-renewable when taken on such a scale. The sun is not 'renewable', it's energy is not 'renewed' and will eventually run out, therefore solar power is not renewable by this argument. Wind power is also driven by thermal energy (ultimately from the sun), and possibly the rotational energy of the earth, and therefore not ultimately renewable. Surely this discussion should be moved to a different page - perhaps the general discussion of Renewable Energy and we can assume on this page that 'Renewable Energy' applies to energy that will remain available until the earth stops spinning, by which time we might have other problems. Timbits82 (talk) 23:35, 23 March 2010 (UTC)


 * Agreed. It should just be deleted because it's silly. Fig (talk) 00:44, 25 March 2010 (UTC)
 * Done. Ghmyrtle (talk) 09:00, 25 March 2010 (UTC)

External links modified
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 * Added archive http://webarchive.nationalarchives.gov.uk/20100817004324/http://www.berr.gov.uk/files/file10719.pdf to http://www.berr.gov.uk/files/file10719.pdf
 * Added archive https://web.archive.org/web/20060419010714/http://www.dti.gov.uk/renewables/publications/pdfs/severnbarragemainreport.pdf to http://www.dti.gov.uk/renewables/publications/pdfs/severnbarragemainreport.pdf
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 * Added archive https://web.archive.org/web/20060928085838/http://www.severnestuary.net/scosla/ to http://www.severnestuary.net/scosla

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Correction needed to pic caption
The caption says GW signifies "million watts" ( aka MW). GW stands for Gigawatt ie "billion watts" HarryRob (talk) 20:25, 18 January 2024 (UTC)

Style of dated headings
I don't like the long hyphen in eg: Corlan Hafren—2011 Does this need any more than a space? Or a comma? S C Cheese (talk) 10:46, 15 March 2024 (UTC)