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Rejection of Severn tidal barrage provokes response

Engineering firms have hit out at the government’s rejection of plans to build a tidal barrage across the Severn Estuary.

One group of companies even claims to have a plan to deliver the barrage for almost half the government’s project cost and without significant public investment.

A government feasibility study released today concluded that a barrage between Somerset and South Wales would cost £34.3bn and investment in other low-carbon schemes would represent better value for money.

Chris Huhne, secretary of state for energy, said: ‘The study clearly shows that there is no strategic case at this time for public funding of a scheme to generate energy in the Severn Estuary. Other low-carbon options represent a better deal for taxpayers and consumers.’

This included the option of smaller projects such as a lagoon across Bridgwater Bay (£17.7bn estimated capital cost) or the Shoots barrage (£7bn) further upstream, which the study concluded did not offer cost or energy yield advantages over a single larger scheme.

However, Corlan Hafren, a consortium of firms, including Halcrow Group, Ove Arup & Partners and KPMG, has put forward an alternative analysis of the potential costs of the barrage.

‘Our cost estimates are closer to £17bn or £18bn, which is a hugely different sum,’ Halcrow director Ben Hamer told The Engineer.

‘Our independent studies show the cost of electricity is going to be comparable with offshore wind and cheaper if you add in the intermittency factor of wind.’

He said the relatively low-tech engineering required to build the barrage meant it was not as risky as the government was predicting and this meant the official cost estimate was too high.

The government report said the project would be unlikely to attract the necessary private investment in current circumstances.

Severn Tidal Power Group, another consortium, including Balfour Beatty and Taylor Woodrow, agreed with this analysis, saying the decision had left the project ‘in limbo’.

‘The upfront costs of getting planning consent are very high and planning consent can be withheld at the secretary of state’s decision at a very late stage,’ the group’s spokesman, Roger Hull, told The Engineer.

‘I can’t see any private sector company spending large amounts of money to push forward planning consent. After consent is in place, that might be a different matter.’

But Hamer said Corlan Hafren had spoken to a ‘raft of investors’ and expected sources, including venture capital firms and pension funds, to be interested in different aspects of the project, depending on the risk level.

‘Importantly they need to be given the right signals that if this were something they were to invest in, government would support it through political mechanisms, albeit we understand they’re not in a position to support financially,’ he said.

Tom Foulkes, director general of the Institution of Civil Engineers (ICE), welcomed Corlan Hafren’s report as ‘innovative forward thinking’.

‘However, government’s role in this austere environment remains vital,’ he added. ‘It must help unlock private investment through the provision of a clear long-term road-map, fit-for-purpose regulatory framework and a democratic, efficient planning system.’

While ruling out the barrage in current market conditions, the Department of Energy and Climate Change (DECC) also said it wants half of the 59GW new generating capacity needed by 2025 to come from renewable sources, particularly wind.

The other half is being left open to nuclear and carbon capture and storage (CCS) options but without specific targets. Despite reiterating its policy of no public subsidy for nuclear energy, the government has confirmed eight potential sites for new nuclear power stations and ruled out three others.

Launching a further consultation on its draft energy National Policy Statements, DECC also announced the regulatory justification of new nuclear reactor designs by Westinghouse and Areva, and set out more detail on requirements for clean-up by new nuclear developers.

Huhne said: ’I’m fed up with the stand-off between advocates of renewables and of nuclear which means we have neither. We urgently need investment in new and diverse energy sources to power the UK.

‘We’ll need renewables, new nuclear, fossil fuels with CCS and the cables to hook them all up to the Grid as a large slice of our current generating capacity shuts down.

‘The market needs certainty to make this investment happen and we are determined to clear every obstacle in the way of this programme.’

Foulkes of the ICE said the government would need to significantly ramp up progress if it wanted half of new generating capacity to come from renewable sources by 2025.

He said: ‘Government will need to focus [on] supporting the development of the supply chain and skills base to support this growth, as well as eliminating the lingering obstacles to private investment.’

A consortium of UK engineering firms is proposing a barrage across the Severn Estuary that could, it is projected, harness tidal energy to generate double the output of a nuclear power station. Click here to read more.

Readers' comments (9)

  • This was hardly surprising given that in reality the wind and tidal power schemes have failed to deliver anywhere near their projected outputs. This has led to them being very expensive, and an expense bourne by the taxpayer. When the feed in tariffs are reduced we will see very expensive electricity from these sources, a cost which will be bourne by industry and domestic consumers.

    Considering the current economic situation of the UK, and much of the manufacturung world, it is not economically viable. When we compare our industrial costs to those of emerging nations they are massively expensive, and any cost to industry is not advisable. By reducing industrial overheads, we can at least narrow this gap, and hopefully develop new industries with reasonable overheads which can compete more favourably.

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  • The critics of the governments rejection are right, this is a project that is quite conventional in its goals, so loading the costs as 'risky technology' doesn't make sense.

    Perhaps if the government said yes they would approve a suitable plan but it's up to the private sector to finance it.

    Be nice to see a predictable and reliable source of green energy for a change!

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  • If we are to have renewable sources of energy, as we must have, then tidal should be at the top. It is the only form which delivers totally predictable output, year after year. Wind is totally unpredictable, solar PV even more so and grossly inefficient to boot, and any form of micro-generation far too expensive to make any impact. It will be down to private industry to 'save our bacon', and rightly so. Perhaps they will then be able to export their technology and get some income for the country!

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  • No matter whether we think this is a good thing or not it would appear that the government may be using spurious figures to validate policy. I wish I could automatically see this as the engineering companies having an equal probability of being in error or the governments figures being an "honest mistake" but I'm afraid that I cannot. If engineering is to be allowed to flourish then we must find a way of taking the government to task. This is something that has become more and more apparent to me reading these newsletters from The Engineer over the past month or so. Surely there must be someone who reads these who is in a position to form a lobbying group?

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  • Surely the important thing about the Severn Barrage is how small the energy output would be for the environmental damage it would do.

    It could supply 5% of our electricity - not bad you might say, but our total energy is 8 times this, so it could only supply 0.63% of our total energy needs.

    It is not true to say, as S. Martin does that wind power has not delivered its projected output

    It is also worth noting that our total nuclear capacity at present produces only 2% of our total energy needs, so there is not much point looking there either to solve 100% of our energy problem.

    Could I point Peter Langridge in the direction of "Without Hot Air" where he will see the calculation that shows the amount of tidal energy around the UK is far too small to provide our present total energy needs, not to mention being vey expensive.

    It is not true as S. Martin asserts that wind power has not delivered its projected output. I assume he is referring to the fact that wind turbines only produce electricity 30% of the time. This is in fact by design. A wind turbine could be built to work 50% of the time, but it would so large, the gain would not be worthwhile. A 30% availability is the "sweet spot" that gives the lowest-cost electricity.

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  • S Martin: What "tidal power schemes have failed to deliver"? The only one I know of: La Rance - would someone please do a benefit-cost analysis over those years of service? The nearest analogy for the Severn Barrage tidal power is the great hydro-electric schemes of the 50's and 60's. Likewise, it would be good to see how they trade off after around fifty years (and still going).
    Tidal power is absolutely reliable, but varies daily. If two-way turbines are used, this smooths some of the peaks, the rest is overall management of the 5% of the electrical grid requirements (from the Severn estuary). And an end to the completely uninformed scare stories (including from the BBC) about its effects.

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  • The Governments own figures clearly show that both wave and wind power have failed to meet even 50% of their projected output. Considering returns and investment figures were based on these figures, the country has been left an expensive legacy.

    PV systems are another issue well documented as they based their projections on maximum output of their systems. In the UK this only averaged 7% of their projected maximum output due to our weather.

    This is the reason Labour chopped the spending on both wind and wave power. This does not consider those turbines closed down by local pressure because of the excessive noise in operation.

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  • A sad day for engineering

    Brian Pollard, but doesn't without hot air include the severn barrage in all its calculations as a slam dunk obvious under all scieneros.

    The technology is not risky at all compared to off shore wind. Provides potential for some power storage.

    Its also a nice bit of world leading engineering that would put britian at the front. 5% of UK electricity is a HUGE number its covering the South Wales and Bristol consumption with green power.

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  • UK plc needs to plan it’s energy needs to be both self sufficient in energy and requires a guaranteed supply of electricity so that the ‘lights in the UK don’t go out’ AND we also need realistic expectations.
    Looking ahead we know that long term we cannot rely on imported oil and gas as costs will continue to rise and, in the case of gas, we will be held to ransom by Russia on price and in peak demands we will find ourselves with diminished supplies as central Europe will consume the gas before it arrives here. As a result fuel prices will be driven up by a combination of extraction costs and Russia wanting a ‘market rate’ for it’s gas costs combined with government taxes on motoring sold politically to the public on the basis of being ‘green taxes’. More important coal and oil are too valuable as raw materials for the chemical and plastics industries to burn as fossil fuels.
    The future will see electric cars with hydrogen fuelled cars either powered with a hydrogen fuel cell (already used on buses) or an hydrogen fuelled internal combustion engine. (proven 1960’s technology – proven as part of the US Sun City project on a US military base assessing how we would live with nuclear fusion generated electrical power – the nuclear reaction occurring in the sun, hence the Sun City project harnessing the power of the sun). Joint European Torus is working towards containing the fusion reaction of joining heavy hydrogen (Deuterium and Tritium) atoms to form a short lived alpha particle (Helium nucleus) and a neutron particle. Whether battery or hydrogen gas powered such cars will need a significant increase in electrical power generation to charge batteries or generate hydrogen by the electrolysis of water.
    The Sun City project also established that people in ‘Sun City’ did not want to heat their homes by electricity or cook by electricity but wanted to cook and heat their homes with gas so that water was electrolysed to produce hydrogen gas in the home and used for both cooking and heating.
    It is clear that in future electricity will form a significantly greater share of our energy needs and we will have to significantly increase our electricity generation to meet demand 24 hours a day in a cost effective way and that means a combination of nuclear power operating under constant load and energy storage systems that can produce electricity on demand when required by the national grid.
    Wind power, especially land based wind turbines, cannot meet that need and it is neither cost effective or green. At best land based wind turbines can turn a generator under load for 20% (approx 5 hours a day with 3 hours a day of usable power) of the time whilst sea based turbines can turn a generator under load for 25% of the time – neither in a predictable manner for national Grid managers. As a result, the national grid has fossil fuel power stations steamed up (i.e. burning fossil fuel) to guarantee electric power when the wind isn’t strong enough!! They are not green as the concrete used in their foundations generates immense amounts of CO2 causing the greenhouse gas they are supposed to be there to prevent and need massive taxpayer subsidies to build AND consumer subsidies to install national grid lines to collect the power when producing and to subsidise the running costs.
    Tidal power water turbines with bi directional turbines which can turn a turbine under load for 85% of the time with clock work precision as we can predict the times when tides rise and fall and we know the water turbines have insufficient flow at turn of tide as there is no flow at turn of tide and they cant rotate under load for a short time either side of the turn of tide. Turning under load 85% of the time means water turbines can produce their full load for 20.4 hours a day and their output is predictable and hence beneficial to National Grid planning. Furthermore, as water has a greater mass than air, the water turbines do more work than a wind turbines.
    Returning to the problems of the National Grid – Power demand varies during the day in a predictable manner with peak demands between 4pm and 6pm when people arrive home and workplaces and shops still open - AS electricity can not be stored on the grid we have to use off peak electricity (Economy 7 cheap tariffs) or lose it unless we store it at night to release as electricity at peak demand time during the day. Batteries are too expensive and inefficient, fuel cells are being developed to do this efficiently and cheaply with the man made hydro-electric schemes being the most efficient – generate electricity during peak demand and pump water uphill on off-peak ‘economy seven’ electricity at night. ‘Joined up thinking’ the CEGB did before privatisation when electric power generation and distribution came under the CEGB in England and Wales and the SSEB in Scotland.
    Land based Hydro-Electric power depends on water availability and is lost during a drought as happened in Mindanao between January and may this year with rotating power cuts for 2/3rds of the day. That said, the UK doesn’t have much in the way of natural hydroelectric power resources with dams built for drinking water storage unlike the Hoover Dam built for power generation. However, I assume we have some scope for converting existing major reservoirs such as Kieder Water into a an upper lake emptying it into a lower lake at peak demand to generate electricity and pumping it back at night under low demand to use again the next day. Not commercially viable with power generation, the National Grid and distribution being undertaken separately – Hence, the reason why the Power Generators are developing fuel cells for storage.
    The problem with both wind and tidal power is that power they generate is intermittent BUT at least tidal power is predictable meaning the National Grid can plan for it whilst wind power is unpredictable and needs back up generating capacity. At present this is done keeping the boilers of conventionally fired steam turbines on steam so that, as required by the National Grid, the steam will be admitted to the steam turbines to rotate the generator shaft and generate electricity. AS SUCH, wind turbines do not reduce fossil fuel usage and green house gas emissions they way the Greens and the renewable Energy Manufacturers and Investors wanting our Tax Payer £’s Sterling would have us believe whilst career politicians Kow Towing to green leaning voters and following EU Diktat don’t understand the issues they are deciding as they are technology illiterate.
    Even worse than the wasted fossil fuel energy keeping boilers steamed up to provide back up power generation is the extensive damage being caused to steam turbine plant used for back up power – Steam turbines and gas turbines are designed for continuous operation at temperature and can withstand very high numbers of dynamic fatigue cycles at elevated temperature but are not resistant to the Low Cycle Thermal Fatigue caused cycling the turbine from ambient temperature to operating temperature and back to ambient temperature caused by each stop/start cycle. I have worked with NEI, GEC, Alstom and Siemens in Power Generation for 26 years and worked in the gas turbines industry for 21 years. A small Industrial gas turbine for CHP and remote power applications can run at 18.000 RPM and endure 1.08 million dynamic fatigue cycles for in excess of 100,000 running hours (11.4 years continuous operation) enduring 108,000 million dynamic fatigue cycles over 100,000 running hours BUT the rotor can only withstand 200 cycles low cycle thermal fatigue – just 200 stop starts.
    In addition to their direct subsidies, the CO2 generated by making wind turbine towers, mainly the concrete foundations, and the additional costs to thermal power generators caused by the National Grid is wearing out conventional steam turbines through low cycle thermal fatigue decades before the end of their designed dynamic fatigue life and the CO2 generated to replace such thermal energy generation plant.
    Returning to water turbines, water turbines are not subject to low cycle thermal fatigue as they do not undergo thermal cycling meaning ‘stored energy’ water turbines can be constructed with two artificial tanks or lakes with water pumped to an upper tank or lake with off peak electricity to store in the water as potential energy during periods of low electricity demand and converting the potential energy in the water by releasing the water through a water turbine to generate electricity on demand.
    The kinetic energy in wind cannot be stored to drive a wind turbine to produce electricity when required BUT, as for water turbines, a wind turbine can be used to store the kinetic energy of wind to pump water to a higher level and store its energy as the potential energy of water stored at a higher level. Potential energy that can be released through a water turbine to generate electricity on demand.
    It relatively simple for a wind and tidal power tidal power system to give power on demand – they need to be partnered by batteries, fuel cells or stored energy water turbines to give electric power on demand to the National Grid.
    In the case of wind power generating electric power for an average of 20% to 25% of the time, the answer is to store all the power in a stored energy water turbine system with two tanks, one above the other. The wind turbine would drive a pump to pump water to the upper tank rather than produce electricity directly and a control system to release the water to flow back to the lower tank through a direct feed water turbine to generate electricity on demand. Will this be done – Not unless politicians legislate for it.
    In the case of Tidal Flow water turbines capable of generating a predictable quantity of electric power for 20.4 hours a day it would require the off peak electricity produced by the installation to store water in a high tank to release through a direct flow turbine to seamlessly complement the tidal flow water turbines by producing electricity either side of tide change when the flow through the tidal flow water turbines cannot rotate them under load to produce electricity.
    Finally – The best of all renewable energy sources from a ‘green prospective’ is timber biomass with fast growing trees like Paulownia Elongata. Paulownia Elongata is the fastest growing hardwood tree with an ignition temperature of 400 deg C making it highly resistant to forest fires. The salient points to note are:-
    ? It grows at up to 31 feet a year and a hectare can crop 150 cubic metres of saleable timber ($41,250 saleable value) every 5 years.
    ? It grows back from the roots every time it is harvested (no replanting costs)
    ? It roots are deep growing and can be grown in on ground with polluted top soils and can be used to recover such soils.
    ? It produces copious quantities of leaves that can be used for feed for livestock.
    ? It produces purple flowers and can produce honey production – the honey is much favoured in south east Asia.
    ? The tops, branches and off cuts from the saw mills can be used for firing biomass turbines (wood burning boilers)
    ? Carbon negative and can be grown as a carbon offset.
    It is carbon negative as only part of the CO2 used in photosynthesis to grow the tree is burnt as biomass because:-
    ? The leaves can be eaten as animal feed, collected for composting or left as they fall to fertilise the top soils meaning the carbon taken from the atmosphere to produce the leaves is permanently removed from the atmosphere.
    ? The carbon in the 150cubic metres of timber harvested every 5 years is also is permanently removed from the atmosphere.
    Only the carbon in the wood in the tree tops, branches, bark and timber mill off cuts is returned to the atmosphere as CO2 when burnt in the biomass furnace to produce steam for electrical power generation:-
    ? Investing in wood burning boilers and and harvesting every 5 years as a combined timber/biomass plantations is carbon negative AND will reduce pressure on rain forest hardwood forests reducing the decline of the rain forest.
    ? Investing in wood burning boilers and harvesting every year biomass plantations is carbon neutral.
    In either case wood burning boilers will produce the dependable power generation output the UK needs.

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