Severn Barrage

The Severn Barrage refers to a range of ideas for building a barrage from the English coast to the Welsh coast over the Severn tidal estuary. Ideas for damming or barraging the Severn estuary (and Bristol Channel) have existed since the 19th century. The building of such a barrage would constitute an engineering project comparable with some of the world's biggest. The purposes of such a project has typically been one, or several of: transport links, flood protection, harbour creation, or tidal power generation. In recent decades it is the latter that has grown to be the primary focus for barrage ideas, and the others are now seen as useful side-effects. Following the Severn Tidal Power Feasibility Study (2008–10), the British government concluded that there was no strategic case for building a barrage but to continue to investigate emerging technologies.[1] In June 2013 the Energy and Climate Change Select Committee[2] published its findings after an eight-month study of the arguments for and against the Barrage. MPs said the case for the barrage was unproven. They were not convinced the economic case was strong enough and said the developer, Hafren Power, had failed to answer serious environmental and economic concerns.[3]

Severn Barrages map
Barrage locations considered over the years. The most westward locations around Ilfracombe and The Gower are not shown. Black indicates lines of most interest, with associated peak power generation at that location.


There have been numerous proposed projects over the years, initially to provide a safe harbour and more recently to generate electricity.

Early projects

Thomas Fulljames's own impression of his proposed Barrage

In 1849 Thomas Fulljames, a civil engineer and the county surveyor for Gloucestershire proposed a barrage from Beachley to Aust (now the site of the first Severn Bridge), a span of just over 1 mile (1.6 km). Since this was before commercial electricity production, the first proposals were based on the desire for a large shipping harbour in the Severn Estuary, road and railway transport, and flood protection.[4]

Severn River Tidal Power Project 1921
Diagram of a plan to harness tidal power on the River Severn circa 1921. Caption from Popular Mechanics Magazine 1921

No action was taken on Fulljames's proposals and three quarters of a century later, in 1925, an official study group was commissioned. An awareness of the large tidal range of 14 metres (46 ft),[5] second only to Bay of Fundy in Eastern Canada,[6][7] led to a proposal to generate 800 Megawatt (MW) of electricity at English Stones and although considered technically possible, it was prevented on economic grounds (then costing £25 million).[8] The viability was tested a few years later in 1931 when Paul Shishkoff,[9] a Russian immigrant, demonstrated a 300 horsepower (220 kW) prototype tidal generator at Avonmouth.[10] It included a novel mechanism for spreading the power output over 24 hours. The full barrage was estimated at £5 million at the time.[11]

In 1933 the Severn Barrage Committee Report (HMSO) from a committee chaired by Lord Brabazon recommended that an 800 MW barrage across the English Stones area would be the best option.[12] The work was interrupted by World War II and then revived in 1945 when engineers predicted an output of 2.2 terawatt hours (TWh) per year.[13] A further government study looked at barrage options in 1948 and estimated the construction costs at £60 million.[10] By the time of the next study in 1953 the estimated cost had risen to £200 million.

In 1971 a report by Dr Tom Shaw, a tidal Power expert and advocate proposed a barrage from Brean Down to Lavernock Point. The scheme was estimated to cost £500 million.[14] In 1975 the Central Electricity Generating Board (CEGB), published a study with evidence from Bristol and Salford universities for the Secretary of State’s Advisory Council on Research and Development for Fuel and Power.[15] As this was the era of cheap oil, the council established that a barrage could not be economically viable unless the energy situation deteriorated significantly.

Bondi Committee—1981

Proposed location of Bondi Committee Barrage

After just such a deterioration (due to the Iranian Revolution and 1979 energy crisis) the plans were reinvestigated by the Severn Barrage Committee in 1981. This committee was known as the "Bondi Committee" (after Professor Sir Hermann Bondi). The committee investigated 6 possible barrage locations, from English Stones at the top of the estuary, down to a location largely at sea in the Bristol Channel between Lynmouth in North Devon and Porthcawl in South Wales. It produced a major energy paper,[16] which recommended a 10 miles (16 km) long barrage of concrete powerhouse between Brean Down and Lavernock Point, sluice and plain caissons together with sand and rock-fill embankments. It would have generated 7,200 MW on the flow of the tides (the largest barrage considered could have produced double that power output). This set of plans was strongly built on a few years later by the Severn Tidal Power Group.

In 1984 Wimpey Atkins proposed a smaller barrage at English Stones, in the hope of creating a smaller more economically viable project that would avoid the environmental impact of a large barrage.[17]

Hooker or Shoots Barrage—1987

Cross section of Shoots Barrage turbine housing

This Wimpey Atkins 1984 study was criticised because it did not tackle the issue of silting[18] and in 1987 Arthur Hooker OBE (a former partner of WS Atkins) in conjunction with Parsons Brinckerhoff prepared a revised barrage proposed at English Stones to better tackle this issue.

Parsons Brinckerhoff further updated their earlier proposal in 2006 and current estimates for this barrage (now known as the "Shoots Barrage") would cost £1.4 to £1.8 billion to build, and generate 2.75 TWh of power per year.[19] At the highest tidal range, it would develop a peak output of 1,050 MW, and 313 MW output on average throughout the year.

Cross section of embankment

The barrage would be located just below the Second Severn Crossing—i.e. above Cardiff and Bristol on the estuary—and so much smaller locks would be needed for upstream access to Sharpness and Gloucester docks as the large ports of Portbury and Avonmouth would be unaffected.

Like the STPG proposal, Hooker generates only on the ebb tide. Construction time would be four years. It would be built of rock fill embankment at the coastal sides (more like the proposals for "Tidal Lagoons"), but like the STPG would be sluice caissons and turbines with powerhouse in the middle section.

In April 2009 the Liberal Democrats produced a report called "A Tidal Solution—The Way Forward" that backed the Shoots Barrage along with a number of additional measures for power generation in the Severn Estuary. In September 2009 the report was adopted by the Lib Dem party conference as official party policy.[20]

Severn Tidal Power Group—1989

The £4.2 million study by Severn Tidal Power Group (STPG) built on the work of the Severn Barrage Committee, but also examined other possible barrages, and produced another major energy paper.[21] Its members comprised Sir Robert McAlpine, Balfour Beatty, Taylor Woodrow and Alstom.[22] They concluded that the 1981 plans were the best location for a barrage, but calculated that the power output could be larger, at 8,640 MW during flow, or 2,000 MW average power. This would provide 17 TWh of power per year (about 6% of UK consumption), equivalent to about 18 million tons of coal or 3 nuclear reactors. The cost in 1989 was calculated to be about £8 billion (£12 billion in 2006 money—about the same as six nuclear reactors, but different lifespan), and running costs would be £70 million per year (about the same as 1.5 nuclear reactors).[23]

Diagram of the STPG Barrage

The barrage would use existing technology as used in the Rance tidal barrage in France, the Annapolis Royal Generating Station in Canada and the Netherlands sea barrages. Power would be most efficiently generated only in the flow direction, and this effect on tidal range would mean that the tidal extent would be halved by losing the low tide rather than the high tide. That is, that the tide would only go out as far as the current tidal midpoint, but high tides would be unaffected (unless the barrage was deliberately closed to prevent flooding).

Construction in prefab caissons

The barrage would contain 216 turbines each generating 40 MW for the 8,640 MW total. Arrays of sluices would let the tide in and then close to force it out through the turbines after the tide has gone out some distance outside the barrage. This deliberate building of a head on the water builds pressure that makes the turbines more efficient.[23]

The barrage would contain a set of shipping locks, designed to handle the largest container vessels. Construction would take about eight years and would require 35,000 employees at peak build time. The minimum lifespan of the barrage would be 120 years (about three times that of a nuclear reactor), but could easily be 200 years if decent maintenance was performed.[23]

The STPG appraisal concluded that the electricity generated from the barrage would make the scheme economically viable if given certain "green" advantages, and that the environmental impact was acceptable.[23] Margaret Thatcher's government did not accept this, and shelved the plans. However, since then global warming has radically altered the public perception of environmental damage; and soaring oil, gas and energy costs have made the economics of the barrage much more favourable.

The advent of renewable energy discounts favours electricity generated from "green" sources; and in addition, much lower interest rates make the cost of loans much lower, and long-term financing of such massive projects is now more viable. Consequently, there have been renewed calls for these plans to be re-appraised.

Severn Tidal Reef—2007

Evans Engineering have released plans for what they call a Severn Tidal "Reef".[24] This is a novel structure which aims to overcome the environmental side-effects of a barrage, and can be conceptualised as being half-way between a barrage and a tidal "fence" (a linked string of tidal-stream turbines). The designer, Rupert Evans, had previously worked on a tidal fence proposal, but since dismissed it as unworkable. The reef reduces environmental impact by working with a much smaller "head" of water—just 2 metres (6.6 ft)—thereby reducing the impact of the structure on the estuary water and flow. The smaller head means that the water velocity is much lower and more lower power turbines are required. The load factor will be higher, partly because of the generation being both ebb and flow and the total energy output should (according to a recent report by W.S. Atkins commissioned by the RSPB) be significantly greater than for the Cardiff-Weston Barrage, and is in part a result of siting the structure at the "outer" Minehead to Aberthaw line, which roughly doubles the volume of tidal water available.[25]

Sustainable Development Commission—2007

On 1 October 2007, the UK's Sustainable Development Commission (SDC) published a report looking at the potential of tidal power in the UK,[26][27] including proposals for a Severn barrage. The report draws on a series of five evidence-based reports, one of which summarises all the available evidence from previous studies on a number of Severn barrage options, but focusing on the Cardiff-Weston and the Shoots schemes. The SDC also commissioned a programme of public and stakeholder engagement, which included a national opinion poll and a series of local and regional workshops.[28]

The SDC gave its support to the building of a Severn barrage, providing a number of strict conditions were met. These include:

  • A Severn barrage should be publicly led as a project and publicly owned as an asset to avoid short-term decisions and ensure the long-term public interest
  • Full compliance with the EU Habitats and Birds Directives is vital, as is a long-term commitment to creating compensatory habitats on an unprecedented scale
  • Development of a Severn barrage must not divert Government attention away from much wider action on climate change

The SDC also raised the challenge of viewing the requirement for compensatory habitat as an "environmental opportunity", through the potential to combine a climate change mitigation project with the adaptation that will be required to respond to the effects of climate change. A publicly led project would enable the use of a low discount rate (2%), which would result in a competitive cost of electricity, and would limit the economic impact of even a very large-scale compensatory habitats package. Electricity production costs are not competitive if a commercial discount rate is applied.

UK Government study announced—2007

A two-year feasibility study was announced in late 2007,[29] and the terms of reference were announced on 22 January 2008,[30] following the publication of the Turning the Tide report from the Sustainable Development Commission. This study builds upon past studies and focuses on a variety of tidal range technologies including barrages and lagoons, and innovative designs such as a tidal fence and a tidal reef in the Severn estuary.

The study, initially led by John Hutton, Secretary of State for Business, Enterprise and Regulatory Reform, was then led until the 2010 General Election by Ed Miliband, who was at that time the Secretary of State for Energy and Climate Change.

The study aims to gather and assess evidence to enable the Government to decide whether it could support a tidal power scheme in the Severn Estuary and if so on what basis. Key work areas involved are:

  • The environmental impacts on biodiversity and wildlife; flood management; geomorphology; water quality; landscape and compensatory habitat;
  • Engineering and technical areas such as options appraisal; costs; energy yield, design and construction, links to the National Grid and supply chain;
  • Economic considerations—financing; ownership and energy market impacts;
  • The regional social, economic and business impacts;
  • Planning and consents—regulatory compliance; and
  • Stakeholder engagement and communication.

The feasibility study concluded its first phase when a public consultation was launched on 26 January 2009. The consultation covered a proposed short-list of potential tidal power project options from an initial list of 10 schemes, processes that were undertaken during shortlisting and the proposed scope of the Strategic Environmental Assessment (SEA). The SEA is a formal environmental assessment of plans or programmes which are likely to have significant effects on the environment.[31] A consortium led by Parsons Brinckerhoff (PB) and Black & Veatch (B&V) has been appointed to manage this part of the project. The process is guided by a stakeholder steering group. The study will culminate in a full public consultation in 2010.[32]

In July 2009 the Government response to consultation confirmed detailed study would be carried out in the second phase on the five schemes that were proposed for short-listing in January. It also announced work to bring forward 3 further schemes that are in the very early stages of development. In September 2010, The Observer reported that the government intended to rule out the possibility of public funding for a complete barrage, while recommending that further feasibility studies be carried out on smaller projects.[33] On 18 October the government announced that the project was being abandoned.[34]

Corlan Hafren—2011

In December 2011 it was reported that the government was talking to Corlan Hafren, a private sector consortium,[35] about a proposal to build a privately financed barrage from Lavernock Point to Brean Down.[36] The Department for Energy and Climate Change said it had received the first draft of a business case for the scheme, and that it was an "interesting proposition".[35] The campaign was led in 2012 by politician Peter Hain.[37] It has been suggested by Atkins that similar schemes could be trialled on smaller estuaries in advance of the Severn, for example the Mersey and Duddon.[38] However the Hafren Power plan collapsed after it was rejected by three independent committees of MPs and by the Government. On 14 January 2014 it was announced that the Chairman and Chief Executive of Hafren Power had resigned, putting an end to the Severn Barrage project.[39]

Economic impact

Power generation potential

The Severn Barrage plans would provide a predictable source of sustainable energy during lifetime of the scheme, with claims of up to 5% of the UK's electricity output from the 10-mile version.[40] This could reduce the cost of meeting UK’s renewable energy targets, and help the UK to meet such targets, including those to tackle climate change.[26] This is because of the few carbon emissions associated with the plan, because unlike conventional power generation, the Severn Barrage plans do not involve the combustion of fossil fuels. A consequence of this plan is that the carbon payback time—the time it takes for saved carbon emissions (those produced by generating the same amount of power in other ways) to outstrip those produced during construction— could be as little as four-and-a-half months, although likely to be around six.[41]

It could continue to operate for around 120 years,[26] compared with 60 years for nuclear power plants.[42] An additional benefit would be to improve energy security.[26]

However, although power supply is predictable, peaks in generation from the barrage do not necessarily coincide with peaks in demand. There are two major tidal cycles affecting power output:

  • semi-diurnal cycle: the familiar daily rise and fall of the sea with a full cycle every 24 hours and 50 minutes, with two high and low tides, giving maximum power generation opportunities a few hours after each of the two high tides;
  • spring-neap cycle: a 29.5 day tidal range cycle with the lowest power days producing about 25% of the power of the highest power days.[43]

Just under eight hours per day of generation time is expected.[43]

Construction costs

Estimated costs for existing plans could be as low as £10bn and as high as £34bn. Recent studies[44] have suggested that the smaller short-listed options could be privately financed, and so in effect the matter of cost and risk becomes a private one between the building consortium and their banks. Schemes of the scale of Cardiff-Weston are likely to require significant Government involvement. If the banks feel that a smaller project is viable and decide to lend the money at an acceptable cost of finance then the projects will go ahead (subject to planning and other approvals). None of this cost would directly fall on the tax-payer but any support mechanism for the tidal power would be likely to fall on consumers. There would, though, be secondary knock-on costs from the tidal power project that might be met by the tax-payer, such as modifying existing ports, provision of compensatory habitat and dealing with environmental change. However, these would be offset by the positive knock-on effects, such as flood protection – which would have otherwise also cost tax-payer money. Whether the parties actually decided to exchange money for these knock-on effects would be a matter for Government negotiation.

As a cost comparison, Hinkley Point C nuclear power station (also being built on the Severn Estuary) will cost £25bn, and deliver 3.2GW of power sold at £92.50 per megawatt hour (MWh) of electricity generated for the 35 years of the contract.[45] The Hafren scheme proposers state they would require £25 billion capital investment, and power costs would be £160 per MWh for the first 30 years, and £20 per MWh thereafter. Other schemes have been costed at between £150 and £350 per MWh.[2]

Local impact

Some say that a large-scale barrage would create leisure-friendly water conditions behind it but with around 10 m rise and fall this would still be one of the largest tidal ranges in the UK bringing with it significant danger to any leisure users. Flood protection would be provided by the barrage, covering the vulnerable Severn estuary from storm surges from the sea but drainage from land upstream would be impeded causing worse flooding there. Also higher water levels downstream of the barrage could cause flooding on the Somerset Levels. New road and/or rail transport links could be built across a barrage if demand rises in the future, as outlined below. Any barrage could provide a boost to the local economy – construction industry in the short term, tourism and infrastructure in the long term.[46]

However, shipping would have to navigate locks and the reduced depth of water would prevent much existing shipping from being able to access docks in Wales and Bristol putting thousands of jobs at risk.[47] Other existing estuary industries, including fisheries, would be damaged and jobs lost.[48] All industrial discharges into the River Severn (e.g. from Avonmouth) would have to be reassessed.[49]

Environmental impact

The Severn Estuary is a Special Area of Conservation due to the European importance of its ecology. The inter-tidal area provides food for over 85,000 migratory and wintering water birds, and represents 7% of the UK's total estuaries.[50] There are nature reserves and Site of Special Scientific Interest (SSSI) on the islands of Flat Holm[51] and Steep Holm.[52]

The Barrage was not supported in the 2003 Energy Review due to "strong environmental concerns" (The same paper also described nuclear power as "an unattractive option").[53]

The RSPB opposes any Severn Barrage because of the effect it will have on the feeding grounds that 85,000 birds depend on, stating "The impact a barrage would have is huge. This is one of the most important sites in the UK for wild birds and the chances of them surviving if it went ahead are fairly slim. There would not be enough room left for all the birds and there would not be enough food for those that remained. The estuary is one of the UK's most important sites for water birds and its wildlife value must be taken fully into account."[54]

Possible effect of turbidity reductions in Severn Estuary

The present strong tidal currents in the estuary serve to lift up silt sediment and so keep the water thick with fine particles—around 30 million tonnes of suspended sediment move in the Estuary on a high Spring tide. This blocks light-penetration and means that the Severn Estuary marine environment is actually a relative desert, in terms of both plant and fish life.[55] The zone of maximum turbidity is confined to the inner Severn and does not extend westwards into the Bristol Channel.[56] An estimated 6.4 million tonnes/year of sand moves up and down the Bristol Channel[57] which would be blocked by a tidal barrage; the potential environmental consequences of interrupting this flux of sand include local coastal erosion and loss of coastal habitats.

The barrage will not create a "lagoon"—as both opponents and supporters have sometimes claimed. Tidal power stations by definition require that the tide flows through the barrage, but the tidal range in the Severn would be halved.[54] There are claims that the migration of fish would be hampered, but these are contested. The Severn bore would also be eliminated. Any barrage would be likely to stimulate coastal erosion in some areas, and create a negative visual impact upon the landscape (subjective, similar to wind turbines). There would also be negative consequences of the huge amount of concrete (and other materials) needed, with the quarrying of stone likely to impact on other areas.

DEFRA claims that the environmental effects of the barrage still need more analysis before final conclusions can be drawn. The Sustainable Development Commission is investigating UK tidal resources, including tidal power in the Severn Estuary and its environmental impact, and should report mid-2007.[58]

Tidal lagoon alternative

Friends of the Earth support the idea of tidal power, but oppose barrages because of the environmental impact. They have proposed their own plans based on the concept of tidal lagoons,[59] whereby man-made lagoons in the estuary would fill and drain through turbines. Their proposals would include lagoons covering up to 60% of the area covered by the barrage, which in some smaller configurations would not impound water in the ecologically sensitive inter-tidal areas of the estuary. The lagoons could be sub-divided so power would be generated at more states of the tide than a barrage, with lower peak output, giving economic advantages to set against the higher construction cost of longer barriers. This idea is based on a prototype now being proposed at Swansea bay. However leading figures in the construction industry are sceptical that the lagoons can be economic.[60][61][62]

A set of Tidal lagoons known as the "Russell Lagoon concept" were studied and dismissed by the 1981 Bondi Committee report, rejected on the grounds of both economics and environmental damage. Studies suggested that tidal currents around and between the lagoons would become extremely fierce and damaging.

Tidal Fence

Another possibility is to construct one or more tidal fences across the Severn estuary which would generate power using tidal stream generators. This has been put forward by the Severn Tidal Fence Consortium, and groups including IT Power and a number of industry and academic groups.[63] This would attempt to maximise the potential power generated whilst allowing for shipping to reach Cardiff and Bristol without hindrance (through gaps at least 650 m wide) and wildlife to maintain their existing habitats. The group has now been contracted by the UK government to investigate the idea under the Severn Embryonic Technology Scheme (SETS).[64]

The group estimates that it would cost £3.5bn to construct an outer fence from Aberthaw to Minehead which would generate 1.3GW or 3.5TWh/year. It is also investigating an inner fence from Lavernock Point to Brean Down including Flat Holm and Steep Holm islands. Both fences could possibly be built.

The fence would permit the migration of salmon and would only slightly affect the mudflats used by migrating birds. In addition it could significantly reduce the flood risk in the Severn estuary.[65]

A second approach to a tidal fence being explored by VerdErg uses a different way of generating electricity called the Spectral Machine Energy Converter (SMEC).[66] This uses the flow past Venturi tube sections as a pump without moving parts to create a large secondary flow which drives turbines on the sea bed.[67] Verderg estimate that they could produce output of 13.7TWh/yr at a cost of £9.9bn using the Lavernock Point/Brean Down connection.

Some simulations have also been done on the partial barriers envisaged by Dynamic tidal power which have similar advantages.

Effects of different site locations

One of the complicating factors in assessing the impacts of a barrage is the large number of possible locations and sizes for the barrage. Generally, the larger the barrage the bigger its environmental impact, and the greater the amount of energy it could transfer—and therefore the bigger carbon offset it could have by way of its renewable power generation.

The largest barrages (sited beyond Hinkley Point and towards Minehead on the English side and Aberthaw on the Welsh side) would significantly affect the entire Severn Estuary and much of the Bristol Channel, but could generate 15 GW peak power and protect the whole of the Somerset levels against flooding and sea-level rise caused by Global Warming. The smallest barrages (sited at Aust/Chepstow) would affect only the river and estuary in Gloucestershire, but would also only generate perhaps 0.75 GW peak power.

A 2009 Paper by Atkins[68] re-evaluated the potential energy which could be generated from the various locations, and concluded that, contrary to earlier studies and computations, the maximum power potential would come from an Ilfracombe-Gower barrage, much further west even than the earlier Minehead-Aberthaw proposals. This was attributed by the study to several calculation elements which were neglected in previous numerical models.

Trans-barrage transport links

It is possible that some types of barrage could be used for transport links between southern England and southern Wales, and more specifically the areas around Weston super Mare and Cardiff but no demand surveys have been carried out to show whether such a link would be useful to commuters or businesses. The east-west position of any future barrage will impact the utility of any transport links across it. Various proposals include a dual carriageway road giving a further crossing in addition to the Second Severn Crossing and the Severn Bridge. The road would have to be taken over the sea locks on a bridge at a height of the Bridge of the Americas (i.e. with a clearance of 61.3 m) if the locks are Panamax-sized.

Some proposals also include a double track railway line across the barrage. A railway would have a longer approach up to a fixed bridge over the locks. The approach would be greatest for non-electrified heavy railway capable of taking freight, slightly less for non-electrified passenger line, and less still for electrified passenger line. There is no electrification presently in the Bristol or Cardiff areas, but this would change with the electrification of the Great Western Main Line. An alternative to a fixed bridge would be a swing bridge, though there is concern expressed at this reducing capacity through the locks and on the railway. However, two swing bridges, one at either end of the lock would mean that one bridge could be kept open to railway traffic at all times. The double track could be reduced to single track at this point without creating too much of a bottleneck, or if double track is required this could be worked around by grade separating the two lines and having double-decked bridges. The line could then be used to partially relieve the Severn Tunnel.

The option for a new fixed rail link has implications for several wider transport proposals. One of the proposed routes for an Irish Sea Tunnel is from Fishguard, which would generate large amounts of extra freight traffic which the current Severn tunnel—already operating at capacity—could not handle. Additionally, a new high-speed rail route has been suggested between London, Bristol, and Cardiff, which faces similar capacity constraints.

If the barrage is built further west, any transport connection would instead link more isolated areas of the Devon-Cornwall peninsula with the cities of South Wales and the ports of Pembrokeshire.




See also


  1. ^ "Severn Tidal Power Feasibility Study Conclusions". Archived from the original on 19 September 2010. Retrieved 25 December 2010.
  2. ^ a b "Energy and Climate Change – Second Report". Parliament UK. Retrieved 21 April 2014.
  3. ^ Energy & Climate Change Select Committee. "MPs say case for Hafren Power barrage scheme unproven". A Severn Barrage?.
  4. ^ Carne, Brian (1995). "Thomas Fulljames 1808–74" (PDF). Transactions of the Bristol & Gloucestershire Archeological Society. CXIII: 16–17.
  5. ^ "Severn Estuary Barrage". UK Environment Agency. 31 May 2006. Archived from the original (PDF) on 30 September 2007. Retrieved 3 September 2007.
  6. ^ Chan, Marjorie A.; Archer, Allen William (2003). Extreme Depositional Environments: Mega End Members in Geologic Time. Boulder, Colorado: Geological Society of America. p. 151. ISBN 0-8137-2370-1.
  7. ^ "Coast: Bristol Channel". BBC. Retrieved 27 August 2007.
  8. ^ "£650 Million barrage plan unveiled". Burnham on 4 March 2006. Retrieved 10 August 2008.
  9. ^ Pavel Aleksandrovich Shishkov (1887–1958) (Biographical information in Russian.)
  10. ^ a b "The Severn Barrage" (PDF). Royal Academy of Engineering. Archived from the original (PDF) on 12 June 2011. Retrieved 10 August 2008.
  11. ^ "How Continuous Power Is Produced By Tide", November 1931, Popular Mechanics article detailed drawing of how unique 24-hour tidal system worked
  12. ^ "Research Report 3—Severn Barrage Proposals" (PDF). Sustainable Development Commission. p. 17. Retrieved 10 August 2008.
  13. ^ "The Severn Barrage" (PDF). Friends of the Earth. September 2007. p. 27. Retrieved 10 August 2008.
  14. ^ Brooke, Gerry (4 August 2008). "Back to the drawing board". Western Daily Press. This is Bristol. Archived from the original on 19 September 2012. Retrieved 12 December 2009.
  15. ^ Bryant, Paul. "History of Severn Barrage proposals". r-energy. Archived from the original on 25 August 2011. Retrieved 8 December 2010.
  16. ^ Tidal power from the Severn Estuary—Volume 1. Energy Paper 46. HMSO. 1981.
  17. ^ Institution of Civil Engineers (Great Britain) (1990). Developments in Tidal Energy. Thomas Telford. p. 3. ISBN 978-0-7277-1571-5.
  18. ^ HL Deb, 7 March 1984 vol 449 cc263-5
  19. ^ McKenna, John (3 October 2007). "Will the new fesibilty study into the Severn Barrage be the first steps towards construction or another false dawn?". New Civil Engineer. Retrieved 12 December 2009.
  20. ^ "Lib Dems back small-scale Severn Shoots barrage proposal".
  21. ^ The Severn Barrage Project: General Report. Energy Paper 57. HMSO. 1989.
  22. ^ Excell, Jon (19 June 2006). "Severn barrage could meet five per cent of UK energy needs". The Engineer. Retrieved 18 September 2012.
  23. ^ a b c d "Energy Review Consultation Response by Severn Tidal Power Group" (PDF). Severn Tidal Power Group. Archived from the original (PDF) on 4 November 2007. Retrieved 8 December 2010.
  24. ^ "Joseph Evans & Sons Ltd".
  25. ^ "Severn reef plan is 'more green'". BBC News. BBC. 26 November 2008. Retrieved 8 March 2010.
  26. ^ a b c d "Tidal Power". Sustainable Development Commission. Archived from the original on 12 May 2008. Retrieved 11 August 2008.
  27. ^ Kinver, Mark (1 October 2007). "Advisers endorse tidal power plan". BBC News. BBC. Retrieved 11 August 2008.
  28. ^ "Engagement report—Public and stakeholder engagement programme" (PDF). Sustainable Development Commission. October 2007. Retrieved 11 August 2008.
  29. ^ "John Hutton calls for open minds on the future of the Severn barrage". BERR. Archived from the original on 24 July 2011. Retrieved 1 December 2010.
  30. ^ "Severn tidal power study could unlock massive renewable potential". BERR. 22 January 2008. Retrieved 8 December 2010.
  31. ^ "Strategic Environmental Assessment". BERR. Archived from the original on 27 March 2009. Retrieved 27 August 2008.
  32. ^ "Severn Tidal Power Q&A" (PDF). Department for Business Enterprise and Regulatory Reform. Archived from the original (PDF) on 30 December 2008. Retrieved 11 August 2008.
  33. ^ Webb, Tim (5 September 2010). "Severn green energy project loses government funding". The Observer. London. Retrieved 10 September 2010.
  34. ^ "Severn barrage tidal energy scheme scrapped by Huhne". BBC News. 18 October 2010. Retrieved 21 April 2014.
  35. ^ a b "New talks on Severn barrage plan from Cardiff to Weston". BBC News. 7 December 2011. Retrieved 19 January 2012.
  36. ^ Hutchinson, Clare (19 October 2010). "'Real cost' of Severn Barrage £34bn". WalesOnline. Retrieved 18 September 2012.
  37. ^ Evans, Bethan (9 September 2012). "Barrage bid to be looked at – again". The Weston & Somerset Mercury. Retrieved 17 September 2012.
  38. ^ OConnell, Dominic (27 March 2011). "Severn barrage awaits the right time and tide". The Sunday Times. Retrieved 18 September 2012.
  39. ^ Shipton, Martin. "Four key figures in Hafren Power resign". Wales Online. Retrieved 8 October 2015.
  40. ^ BBC (26 January 2009). "Shortlist for Severn energy plans". BBC News. Retrieved 5 March 2010.
  41. ^ "Severn Barrage will pay back carbon in less than six months, says study". 2 March 2009. Retrieved 8 March 2010.
  42. ^ "Extending the Operational Life Span of Nuclear Plants". International Atomic Energy Agency. 8 March 2010. Retrieved 8 March 2010.
  43. ^ a b Turning the Tide, Tidal Power in the UK (Report). Sustainable Development Commission. 30 September 2007. pp. 25, 77–79. Retrieved 8 March 2010.
  44. ^ DECC Severn Tidal Consultation Supporting Documents (Report). DECC. 23 April 2009. Archived from the original on 20 April 2009. Retrieved 25 May 2009.
  45. ^ Syal, Rajeev (4 August 2015). "Deal to build UK nuclear plant should be finalised within weeks". Guardian. Retrieved 8 October 2015.
  46. ^ "£14 Billion Tidal Barrage Proposed for Severn Estuary". Earth toys. 28 October 2008. Retrieved 28 October 2008.
  47. ^ "Severn Barrage 'would destroy port jobs'". SouthWest Business. Retrieved 30 August 2017.
  48. ^ A Severn Barrage: second report of session 2013-14, Vol. 1: Report, together with formal minutes, oral and written evidence. The Stationery Office. 2013. p. 35. ISBN 9780215058843.
  49. ^ "The Severn Estuary: Occasional Paper No 13" (PDF). Marine Biological Association. Retrieved 8 December 2010.
  50. ^ "Severn Barrage is not the answer". Press Release. Friends of the Earth. 11 April 2006. Retrieved 11 August 2008.
  51. ^ "Flat Holm—About the island". BBC. 3 April 2008. Retrieved 12 April 2008.
  52. ^ "Steep Holm" (PDF). English Nature. Retrieved 6 September 2007.
  53. ^ "Energy White PaperOur Energy Future—creating a low carbon economy" (PDF). Department of Trade and Industry. February 2003. Archived from the original (PDF) on 17 August 2010. Retrieved 11 August 2008.
  54. ^ a b "Barrage bad for birds". (Environmental Data Interactive Exchange). Retrieved 10 August 2008.
  55. ^ Kirby, R.; Shaw, T (March 2005). "Severn Barrage, UK–environmental reappraisal". Proceedings of the Institution of Civil Engineers 2005: Engineering Sustainability. Institution of Civil Engineers. 158 (3): 31–39.
  56. ^ Collins, M.B., 1987. Sediment transport in the Bristol Channel: a review. Proceedings of the Geological Association 98, 367-383.
  57. ^ Harris, P.T., Collins, M.B., 1988. Estimation of annual bedload flux in a macrotidal estuary, Bristol Channel, U. K. Marine Geology 83, 237-252.
  58. ^ Bradshaw, Ben (15 March 2007). "Speech by Ben Bradshaw MP to the Wave and Tidal Conference of the British Wind Energy Association". Department for Environment, Food and Rural Affairs. Archived from the original on 13 November 2008. Retrieved 11 August 2008.
  59. ^ "A Severn barrage or tidal lagoons? A comparison" (PDF). Friends of the Earth Cymru. January 2004. Retrieved 1 October 2007.
  60. ^ "Tidal Lagoon Power Generation Scheme in Swansea Bay" (PDF). Department of Trade and Industry and the Welsh Development Agency. April 2006. Archived from the original (PDF) on 30 June 2007. Retrieved 1 October 2007.
  61. ^ "Research Report 2—Tidal technologies overview" (PDF). Sustainable Development Commission. October 2007. Archived from the original (PDF) on 11 May 2009. Retrieved 11 August 2008.
  62. ^ Jonathan Ford (15 January 2017). "Tidal power swamped by dubious mathematics". Financial Times. Retrieved 15 January 2017.
  63. ^ "Tidal Fence instead of Severn Barrage".
  64. ^ "IT Power to lead Severn Tidal Fence Consortium with potential alternative to the Severn Barrage".
  65. ^ "Severn tidal 'fence' idea floated". BBC. 16 July 2008.
  66. ^ "Severn Embryonic Technologies Scheme". Archived from the original on 21 November 2010. Retrieved 25 December 2010.
  67. ^ "SMEC Technology Basic Principles". Retrieved 25 December 2010.
  68. ^ Atkins, R Rainey. "Technical Note: The optimum position for a tidal power barrage in the Severn estuary, Reference CJ0040.6680/TN-001r3" (PDF). Atkins. Retrieved 20 May 2012.
  70. ^ Brooker, Christopher (25 August 2012). "The tangled tale of Lord Deben and a dodgy Severn barrage". Telegraph. Retrieved 5 September 2016.
  71. ^ a b Jones, Gareth (2 June 2006). "Experts disagree on river barrage". BBC News. Retrieved 6 April 2010.
  72. ^ " – John Penrose".
  73. ^ "UK Parliament – Early Day Motions By Details".
  74. ^ "".
  75. ^ "The Webb log: Time to put some energy into power from the Severn".
  76. ^ "House of Commons Hansard Debates for 4 Feb 2003 (pt 5)".
  78. ^ "Byron Meets with Chancellor over Tidal Lagoon". Retrieved 21 November 2016.
  79. ^ a b Estuary energy plan makes waves, The Guardian, 26 April 2006
  80. ^ "Concern over Severn barrage plan". BBC News. 11 April 2006. Retrieved 6 April 2010.
  81. ^ "Severn Barrage—Gwent Wildlife Trust".
  82. ^ "The Severn Estuary a very special place".
  83. ^ Jones, Gareth (27 May 2007). "Monbiot attacks Welsh energy plan". BBC News. Retrieved 6 April 2010.

External links

British Energy Efficiency Federation

The British Energy Efficiency Federation (or BEEF) was founded in 1996 by the United Kingdom Government to provide a forum for consultation between existing industry associations in the energy sector.

David Ord

Sir David Charles Ord (born July 1948) is a British businessman.

Department of Energy (United Kingdom)

The Department of Energy (DoE) was a department of the United Kingdom Government. The Department was established in January 1974, when the responsibility for energy production was transferred away from the Department of Trade and Industry in the wake of the 1973 oil crisis and with the importance of North Sea oil increasing.

Following the privatisation of the energy industries in the United Kingdom, which had begun some ten years earlier, the Department was abolished in 1992. Many of its functions were abandoned, with the remainder being absorbed into other bodies or departments. The Office of Gas Supply (Ofgas) and the Office of Electricity Regulation (OFFER) took over market regulation, the Energy Efficiency Office was transferred to the Department of the Environment, and various media-related functions were transferred to the Department for National Heritage. The core activities relating to UK energy policy were transferred back to the Department of Trade and Industry (DTI).

The Department of Energy was a significant source of funding for energy research, and for investigations into the potential for renewable energy technologies in the UK. Work funded or part-funded by the DoE included investigations into Geothermal power and the Severn Barrage

Energy Retail Association

The Energy Retail Association (ERA) was a trade association which promoted the interests of electricity and gas retailers in the domestic market in Great Britain, formed in 2003. In April 2012 it merged with the Association of Electricity Producers and the UK Business Council for Sustainable Energy to become Energy UK.

Flat Holm

Flat Holm (Welsh: Ynys Echni) is a limestone island lying in the Bristol Channel approximately 6 km (4 mi) from Lavernock Point in the Vale of Glamorgan. It includes the most southerly point of Wales.

The island has a long history of occupation, dating at least from Anglo-Saxon and Viking age. Religious uses include visits by disciples of Saint Cadoc in the 6th century, and in 1835 it was the site of the foundation of the Bristol Channel Mission, which later became the Mission to Seafarers. A sanatorium for cholera patients was built in 1896 as the isolation hospital for the port of Cardiff. Guglielmo Marconi transmitted the first wireless signals over open sea from Flat Holm to Lavernock. Because of frequent shipwrecks a lighthouse was built on the island, which was replaced by a Trinity House lighthouse in 1737. Because of its strategic position on the approaches to Bristol and Cardiff a series of gun emplacements, known as Flat Holm Battery, were built in the 1860s as part of a line of defences, known as Palmerston Forts. On the outbreak of World War II, the island was rearmed.

It forms part of the City and County of Cardiff and is now managed by Cardiff Council's Flat Holm Project Team and designated as a Local Nature Reserve, Site of Special Scientific Interest and a Special Protection Area, because of the maritime grassland and rare plants such as rock sea-lavender (Limonium binervosum) and wild leek (Allium ampeloprasum). The island also has significant breeding colonies of lesser black-backed gulls (Larus fuscus), herring gulls (Larus argentatus) and great black-backed gulls (Larus marinus). It is also home to slowworms (Anguis fragilis) with larger than usual blue markings.

Franco-British Nuclear Forum

The first meeting of the Franco–British Nuclear Forum was held in Paris in November 2007, chaired by the Minister for Energy and the French Industry Minister. The working groups are focusing on specific areas for collaboration. A follow-up meeting on the issue in London was planned for March 2008,[1] but did not take place.[2]

Geoffrey Binnie

Geoffrey Morse Binnie FRS FEng (13 November 1908 – 5 April 1989) was a British civil engineer and writer particularly associated with dams and reservoirs.Binnie was the third generation of his family to enter civil engineering (his grandfather was Sir Alexander Binnie, and father William Binnie). He was educated at Charterhouse School, Trinity Hall, Cambridge and Zurich University. On graduation, he became a pupil of Swiss engineer Dr Henry Edward Gruner, working on a hydro-electric scheme, Seruf-Niederenbach, in the Alps, and then on a larger project, Albbruck-Dogern on the River Rhine.He joined the Binnie & Partners firm of consulting engineers in 1931. From 1932–1936, he worked on the 88m high Jubilee Dam in Hong Kong, the then highest dam in the British Empire. Upon his return to the UK, he worked on the construction of Eye Brook Reservoir at Corby, Northamptonshire. In 1939, he was appointed a Partner in the family firm.During World War II, he served in the Royal Engineers. After the war, he worked on various water supply projects in the UK and overseas, including the Kalatuwawa Dam, near Hanwella, which supplies water to Colombo in Sri Lanka. Other major projects included:

Dukan Dam, on River Tigris, Iraq

Mangla Dam, on the Jhelum River, Pakistan, today still the world's 16th largest dam.

the W. A. C. Bennett Dam, part of the Peace River Project, British Columbia, CanadaBinnie retired in December 1972, but remained active on various committees concerned with dams and barrages, including the Severn Barrage Committee from 1977–1979. He also researched the history of water and dam engineering; his first book Early Victorian Water Engineers was published in 1981, and in 1987, his second book, Early Dam Builders in Britain was published.

Hafren Power

Hafren Power (formerly Corlan Hafren) was a tidal energy business formed to promote construction of a Severn Barrage between Wales and England.

List of tidal power stations

This page lists most power stations that run on tidal power. Since tidal stream generators are an immature technology, no technology has yet emerged as the clear standard. A large variety of designs are being experimented with, with some very close to large scale deployment. Hence, the following page lists stations of different technologies.

New Electricity Trading Arrangements

New Electricity Trading Arrangements (NETA) is the system of market trading arrangements under which electricity is traded in the United Kingdom's wholesale electricity market as of 27 March 2001. The arrangements provided that parties could trade off their imbalances close to real time.

Opus Energy

Opus Energy Limited supplies gas and electricity to businesses across the United Kingdom. It purchases electricity from wind, solar, hydro, and anaerobic digestion generators, and provides support to develop energy-generating sites. It is headquartered in Northampton, United Kingdom with an additional office in Oxford.

Regal Petroleum

Regal Petroleum plc is a petroleum company based in London with assets in Romania, Ukraine, Greece, and Egypt. It was founded by Frank Timiş in November 1996, and is listed on the London Alternative Investment Market.

Score Group plc

Score Group plc is an international engineering business based in Peterhead, Scotland.

Severn Estuary

The Severn Estuary (Welsh: Môr Hafren) is the estuary of the River Severn, the longest river in Great Britain. It is the confluence of four major rivers, being the Severn, Wye, Usk and Avon, and other smaller rivers. Its high tidal range, approximately 50 feet (15 m), means that it has been at the centre of discussions in the UK regarding renewable energy.

Severn Tidal Power Feasibility Study

Severn Tidal Power Feasibility Study is the name of a UK Government feasibility study into a tidal power project looking at the possibility of using the huge tidal range in the Severn Estuary and Bristol Channel to generate electricity.

On 22 January 2008, the Government launched the feasibility study. The study, previously led by the Department of Business, Enterprise and Regulatory Reform (BERR) is now led by the new Department for Energy and Climate Change and includes representation from the Welsh Assembly Government and the South West Regional Development Agency.

Previous reports on tidal power in the Severn did not—and did not aim to—provide a detailed analysis of all tidal range technologies. This feasibility study aims to consider all tidal range technologies, including barrages and lagoons. The focus is on tidal range technologies as this is where the energy potential in the Severn Estuary is the greatest, as opposed to 'tidal flow' which is the current in moving tidal waters. The tidal range in the Severn Estuary is the second highest in the world and can rise as much as 14 metres, meaning it has the potential to generate more renewable electricity than all other UK estuaries. This could create up to 5% of the UK’s electricity, contributing significantly to UK climate change goals as well as European Union renewable energy targets.The Government is carrying out the feasibility study to look at all the costs, benefits and impacts of a Severn tidal power scheme. The study, often incorrectly called the Severn Barrage, looks at all tidal range technologies—including barrages, lagoons as well as other technologies. A decision whether the Government will support the scheme or not will take place after a second public consultation in 2010. It was decided after much debate that the scheme would be closed forever and that this would not be brought up in future discussions to save time.The first consultation of the feasibility study was launched on 26 January 2009 and closed on the 23 April 2009. It looked at the scope of the Strategic Environmental Assessment, the issues the feasibility study considered and the shortlisted schemes up for more detailed analysis in stage two.

Severn crossing

Severn crossing is a term used to refer to the two motorway crossings over the River Severn estuary between England and Wales operated by Highways England. The two crossings are:

Severn Bridge (Welsh: Pont Hafren)

Prince of Wales Bridge (Welsh: Pont Tywysog Cymru), until 2018 known as the Second Severn Crossing (Ail Groesfan Hafren).The first motorway suspension bridge was inaugurated on 8 September 1966, and the newer cable-stayed bridge, a few miles to the south, was inaugurated on 5 June 1996. The Prince of Wales Bridge (Second Severn Crossing) marks the upper limit of the Severn Estuary. From 1966 to 1996, the bridge carried the M4 motorway. On completion of the Second Severn crossing the motorway from Aust on the English side to Chepstow was renamed the M48. The Second Severn Crossing was officially renamed the Prince of Wales Bridge on 2 July 2018.

The two Severn crossings are regarded as the main crossing points from England into South Wales. Before 1966 road traffic between the southern counties of Wales and the southern counties of England had either to travel via Gloucester or to take the Aust Ferry, which ran roughly along the line of the Severn Bridge, from Old Passage near Aust to Beachley. The ferry ramps at Old Passage and Beachley are still visible.

Until 17 December 2018, tolls were collected on both crossings from vehicles travelling in a westward direction only; the toll for small vehicles was £5.60. The Severn Crossing reverted to public ownership on 8 January 2018, run by Highways England.

Thomas Fulljames

Thomas Fulljames FRIBA (4 March 1808 – 24 April 1874) was an architect active in Gloucestershire, England, in the first half of the nineteenth century. As diocesan surveyor from 1832 until 1870, latterly in partnership with Frederick Sandham Waller, he designed, reconstructed or extended a number of churches in Gloucestershire.

He is known for designing the Gloucester Court of Probate (1858) in the Gothic style. He also designed a barrage across the River Severn, which was never built. He built Foscombe house for his own use in Ashleworth, Gloucestershire, which has been classified as a grade II* heritage building.

UK Power Networks

UK Power Networks is a distribution network operator for electricity covering South East England, the East of England and London. It manages three licensed distribution networks (Eastern Power Networks PLC, South Eastern Power Networks PLC and London Power Networks PLC) which together cover an area of 30000 square kilometres and approximately eight million customers.

In 2014 UK Power Networks was awarded £25 million from the electricity regulator Ofgem's Low Carbon Networks Fund for the Low Carbon London project. In 2011 it was awarded £6.7 million by Ofgem for another project, Flexible Plug and Play, which is researching new ways, technical and commercial, to connect renewable energy to the distribution network in Cambridgeshire.

As well as the three distribution arms UK Power Networks also operates UK Power Networks Services Holdings Limited, which develops and maintains electrical networks for clients including London Underground, Heathrow and Stansted airports, Docklands Light Railway and Canary Wharf.

Western Power Distribution

Western Power Distribution is the trading identity of four electricity distribution companies - WPD South West (operating in South West England), WPD South Wales (operating in South Wales) and WPD Midlands (operating in East Midlands and West Midlands). All of the companies act as the distribution network operator for their respective regions, and are registered in Bristol, England. Western Power Distribution serves approximately 7.7 million customers over its combined distribution areas.

Western Power Distribution is a subsidiary of the American utility corporation PPL.

It should not be confused with WPD, a wind farm company in north-western Europe, or Western Power Corporation, an electricity distributor in Australia.

Power stations

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