Energy and Climate Change CommitteeWritten evidence submitted by the Renewable Energy Association, Ocean Energy Group (SEV66)

The Renewable Energy Association (REA) welcomes the opportunity to submit evidence to the Energy and Climate Change Committee for the new enquiry into a Severn Barrage. The REA represents British renewable energy producers and promotes the use of sustainable energy in the UK. The membership is active across the whole spectrum of renewables, including wave and tidal, electric power, heat and transport fuels. Members range in size from major multinationals to sole traders. There are over 800 corporate members of the REA, making it the largest renewable energy trade association in the UK.

The REA’s main objective is to secure the best legislative and regulatory framework for expanding renewable energy production in the UK. The Association undertakes policy development and provides input to government departments, agencies, regulators and NGOs.

In order to cover sector-specific issues, a number of so-called “Resource Groups” have been set up. The Ocean Energy Resource Group (OEG), comprising more than 100 individuals, covers wave energy and tidal energy. The primary focus of the Group is the progress of energy conversion device and array development to prove the capability and survivability of full-scale projects, and the legislative measures required to support and finance projects in order to bring them to commercial fruition.

The proposed Cardiff-Weston barrage scheme is of fundamental interest to the OEG and may have wide-ranging impacts on development of the tidal energy industry in the UK, as well as the renewable energy sector as a whole. This response to the ECCC enquiry was formulated following discussions at a number of meetings of the OEG and includes input from the REA’s experts across the whole spectrum of the renewable energy sector.

The UK Tidal Energy Resource

In 1997, the Marine Foresight Panel reported: “It has been estimated that if less than 0.1% of the renewable energy available in the oceans could be converted to electricity, it would satisfy the world demand for energy more than five times over.”

The UK possesses 50% of Europe’s tidal energy resource (10–15% of the global resource). Exploitation of both tidal stream and tidal head energy offers significant benefits to the UK, through the supply of a clean, renewable and secure source of energy and by contributing to the UK’s 2020 targets for reduction in carbon emissions.

General Comments on the Severn Tidal Power Feasibility Study

The REA welcomes the opportunity to submit evidence to the ECCC enquiry into a privately financed Severn Barrage scheme. We are pleased that the government will reconsider this option for exploiting the UK’s unique and significant power resource in the Severn Estuary—on the same order of magnitude as a conventional power station—while at the same time recognising the challenges of mitigating social, economic and environmental impacts of such a project.

We believe that large renewable energy projects, such as a Severn tidal barrage, must become part of the energy mix if the UK is to achieve its ultimate target of an 80% reduction in carbon emissions by 2050. However, it is vital that the government maintains a long-term view, continuing to support and encourage all other forms of clean energy technology. We are concerned that the government may become complacent once such a large scheme has been consented, ignoring the fact that the 15% target by 2020 represents only a staging post to a contribution way over 15% by 2050.

Evidence on specific topics to be addressed by the enquiry

1. What contribution could the Cardiff-Weston Barrage make to UK energy security and climate change objectives?

As documented in the feasibility study funded by DECC in 2008–10, a barrage crossing the Severn estuary from Brean Down, near Weston super Mare to Lavernock Point, near Cardiff would have an estimated capacity of over 8.6 GW—twice that of the UK’s largest fossil fuel power plant—and could generate nearly 5% of UK’s current electricity demand.

The 2020 renewable energy target of 15% requires deployment at an unprecedented rate, so the sooner the UK can accelerate development the better. Renewable electricity only makes up around 8% of current electricity production and will require a four-fold increase by 2020 in order to make the necessary contribution of 30% to the energy mix, as estimated by DECC1.

However, set against this is the fact that even if the largest barrage were to be completed—and it could be counted towards the UK meeting its 2020 target, even if not completed—this still leaves the bulk of the renewables target to be met. The target is mandatory and the Government cannot afford to take its eye off the ball.

2. What risks and opportunities could it pose with regard to flooding in the Severn estuary, and how might any risks be mitigated?

The REA understands that the potential for flooding may be reduced in the Severn estuary behind the barrage, but there is a danger that coastal flooding may be increased on the seaward side.

3. What risks and opportunities could it pose to wildlife and habitat in the Severn estuary, and how might any risks be mitigated?

It is widely accepted that global warming is the greatest environmental challenge currently facing the human race. The REA believes that the benefits of a tidal barrage for mitigation of climate change would outweigh negative impacts on environmental conservation, although within that proviso, we also believe that all available measures should be applied to reduce harm to the environment.

The documented environmental impacts of a Severn barrage include the loss of bird habitat (mud flats uncovered at low tide) and consequent changes to the existing ecosystem, erosion by waves generated within the impoundment area and reduced suspended sediment load, leading to problems with upstream sedimentation.

Much data on the behaviour of marine mammals and their interaction with turbines continues to be generated through the ongoing monitoring programme for the Seagen tidal power station in Strangford Lough. Although this is a tidal stream (rather than a tidal head) installation, the data is very relevant to the impacts of rotating machinery on marine wildlife. The evidence after three years of monitoring is that no major impacts on marine mammals have been detected.2

An interesting beneficial impact of marine construction for wildlife was noted by members of the REA’s Ocean Energy Group during a trade mission to New Zealand in 2009. The walls of a fish farm in Marlborough Sound provided an attractive haul-out site for marine mammals.

4. What lessons can be learned from the successful development of La Rance tidal barrage in France and other tidal power projects?

The REA understands that the road traffic benefits offered by the barrage across the Rance in northern France were not taken into consideration prior to construction, although they are now widely recognised by the local and tourist population. A number of parties have suggested that the possibility of a Severn Estuary road crossing over a barrage should also be considered.

Both the Annapolis Royale and Rance barrages incorporate a visitor centre, attracting tourists and hence revenue to the region. We believe that this should be taken into account for the social and economic impact assessments of the Severn barrage scheme.

The Rance barrage has provided a safe area for marine leisure activities (e.g. dinghy sailing and kayaking) on the upstream side, which is enjoyed by the local population.

The Eastern Schelde storm surge barrage is a useful analogue for predicting the physical and geological impacts of a barrage in the Severn Estuary. A presentation on this subject was given by Roger Morris of Natural England at the REA’s WATTS conference in 2008. Further information is presented in his paper.3

5. What risks and opportunities could it pose to local employment and community, and how might any risks be mitigated? In particular, what are the consequences for current ports, fishing and aggregate extraction industries in the estuary?

The REA is not qualified to comment on this question.

6. Would the project require support under the proposed new Contracts for Difference mechanism? If so, approximately what level of strike price would be required to make the project economically viable? 

Under current legislation, a tidal barrage of over 1GW in capacity would not eligible for ROCs and the REA agrees that the RO is not an option for a large barrage, given the long term nature of the support needed and the finish of the RO in 2017. However, there is no logic behind excluding it with respect to eligibility for a CfD and we are pleased that the ECCC enquiry will explore this issue.

It is important that the electricity output is subject to the same market forces as other electricity, in order to encourage generation at peak times so that integration with the grid is facilitated. Similarly it is desirable to reduce the cost of capital. Therefore a tariff mechanism that pays a premium over wholesale prices, rather than an absolute tariff, is preferable.

We do not currently hold information about the level of strike price that would be required to make the project economically viable, but if the REA is invited to give oral evidence to the ECCC Committee, we will consult our membership and provide an approximate strike price.

7. How does the company plan to engage and consult the community in the development of the project?

The REA has no information on this subject.

8. Are the proposals in breach of EU legislation, and if so how will this be addressed?

The most contentious issue for any proposed tidal barrage across the Severn estuary is that of environmental impacts on a site protected under EU legislation, because much of the estuary and surrounding mud flat is part of the Natura 2000 network of EU protected sites. The EU Habitats Directive prohibits projects which have an adverse effect on features of the site, unless:

No viable alternative is possible.

Imperative Reasons of Overriding Public Interest (IROPI) is demonstrated.

There is certainly no viable alternative in the UK for a barrage scheme on the scale of a Severn barrage and in view of concerns about climate change and the EU renewable energy targets, arguments in favour of IROPI may well prevail. However, there would still be a requirement for environmental compensation and mitigation measures. If these are considered by the Statutory Nature Conservation Bodies to be inadequate or if they are too expensive to implement, hard decisions must be taken regarding the relative priority of environmental concerns on a global scale (ie mitigation of climate change) and the protection of local features. It is important to bear in mind that in the longer term, global warming may well destroy the beneficial effects of local conservation measures.

9. Are any other proposals for tidal power projects in the Severn estuary currently under consideration?

Pulse Tidal Ltd has been granted an Agreement for Lease of a tidal stream site off Lynmouth, N Devon. The impacts of a barrage on this project must be considered.

The REA believes that other projects are being considered for the Severn estuary, in particular tidal lagoon projects. We do not have further details at present but will investigate if requested to present oral evidence to the ECCC Committee.

10. What could be the wider international implications of the scheme for UK engineering and UK low-carbon industry?

No comment.

11. Further comments

The REA remains concerned about the financial and environmental risks of the Cardiff—Weston barrage and believe that a prudent way forward would be to build a small barrage initially, to assess the costs and monitor the environmental impacts, before progressing to a larger barrage.

One way to overcome this dilemma would be to first build a small barrage elsewhere (for example on the Mersey or Solway Firth) and conduct a thorough, practical evaluation of the social, financial and environmental impacts. If the impacts were deemed to be acceptable, a large barrage could be built on the Severn Estuary, utilising the full tidal head resource.

December 2012