Dear Environmental Audit Committee,

Technological Innovations and Climate Change: Tidal Power

Thank you for the opportunity to our share views on tidal energy.

The RSPB agrees that the UK has significant potential for offshore power generation. However urgent action is required to our response to climate change does not deepen the ecological emergency. This means ensuring the right renewables technology in the right places with enough space for nature. Unfortunately, the current trajectory of offshore renewables deployment risks irreversible wildlife losses and we are concerned that poorly planned tidal could increase the threat, jeopardising both nature and net zero. 

We agree with the EAC’s determination that tidal technology is at the early stages of development and therefore welcome consideration on related issues when determining the role of these renewables in the UK’s commitment to be net zero by 2050. In particular, we note the potential for significant ecological issues and cumulative impacts from all forms of tidal technology and recommend thorough investigation before decisions regarding large scale commercial deployment are made. The range of ecological impacts which can arise from tidal development include collision (stream), disturbance (i.e. noise and/or human activity that causes birds to move away) habitat loss, and loss of access to preferred foraging areas. Due to the impact of tidal technology on coastal processes and sediment, the potential scale of impact may be far reaching extending beyond country boundaries.

In order to facilitate the decarbonisation of our energy systems through marine renewables, we recommend radical and coordinated changes to how we plan energy infrastructure and use our sea space. These changes require urgent action from UK Government in conjunction with devolved administrations and the sector. In this submission we set out these priority changes, identifying specific steps which we strongly recommend the UK Government and devolved administrations progress during the early 2020s:

  1.                                      Government strategic and spatial marine plans which prioritise climate and nature, address environmental impacts at the outset and direct renewable infrastructure to the most suitable locations and facilitate the UK’s energy transition.
  2. Research and monitoring must be mobilised to provide a robust evidence base on how wildlife uses our seas and interacts with renewables technology.
  3. Conservation to secure the long-term recovery and resilience of nature. Renewables infrastructure development is not occurring in isolation. Alleviating the wider pressures on nature is an essential component of reconciling ambition for increased renewables and the associated threats to nature.  For example, given the continued decline of UK seabirds, and the drivers to achieve Good Environmental Status, it is clear we need a major recovery plan for seabirds, prioritising direct action to halt and reverse the continuing decline and increase population resilience. This should include the completion of a well-managed network of Marine Protected Areas (MPAs), fisheries management (forage fisheries and bycatch) and a rolling programme of island restoration.

The RSPB would welcome the opportunity to meet with EAC representatives to explore our concerns and recommendations as part of ongoing efforts to support a timely and sustainable energy transition. We would be very happy to provide additional information on specific cases if helpful.


Yours sincerely,


Helen Quayle
Policy Officer


A Response from the RSPB to the Environmental Audit Committee inquiry into Technological Innovations and Climate Change: Tidal Power



The RSPB is the largest conservation organisation in Europe, with more than 1.2 million members, over 2,000 employees and around 12,000 volunteers. It has over 200 nature reserves across the UK, wild havens where everyone can get closer to nature and home to 80 per cent of our rarest or more threatened bird species. The RSPB also works internationally and is a leading player in BirdLife International, a partnership of conservation organisations working to save nature across the world.


The RSPB and tidal energy

The RSPB supports urgent action to tackle the climate and nature emergencies. Decarbonising energy is a vital part of efforts to reach net zero. However urgent action is required to ensure action on climate change does not deepen the ecological emergency. This means ensuring the right renewables technology in the right places with enough space for nature. This is vital to remove the jeopardy the current approach places on nature and net zero.

The RSPB has had strong engagement in tidal casework including Mostyn/Mostyn Energy Park, the Colwyn Bay tidal lagoon and the Severn barrage. Here we draw on our experience from these and other more recent cases as well as our knowledge of seabirds, the challenges currently facing other marine renewables technology and our ambition to support a sustainable and timely energy transition.


A climate and ecological emergency

Decarbonising energy is a vital part of efforts to reach net zero targets and requires increased deployment of renewable technology. However, the current approach to planning offshore renewables jeopardises nature and net zero. Action on energy and net zero must be integrated with nature to provide joint solutions to the climate and ecological emergencies.

The much-needed expansion of renewable energy must be delivered in harmony with nature; the right technology in the right place with enough space for nature. Emerging technologies such as tidal stream and floating wind have the potential to be the right technology if efforts to find the right places and alleviate the wider pressures on our marine environment are put into place.


The UK’s seabirds

The UK is home to internationally important numbers of seabirds (around 8 million), including 90% of the world's Manx shearwaters, two-thirds of its great skuas and a tenth of its puffins. These birds rely on the UK’s shores and seas to nest and rear their chicks. Unfortunately, seabirds breeding in the UK have declined in abundance and experienced frequent, widespread breeding failures over the last two decades. These declines are the result of climate change and increasing pressure from human activities. Unfortunately, poorly planned offshore wind is adding further pressure and without urgent changes to how we deploy this technology we risk irreversible wildlife losses. All additional energy infrastructure from must be considered in this context of cumulative impacts and increased competition for sea space. To ensure a sustainable and timely energy transition, urgent action is needed.


Tidal energy

Tidal range developments are by their nature significant interventions in the coastal environment with potential for profound changes to physical, chemical and biological processes.  An understanding of their ecological effects depends on understanding their effects on the way they change the geomorphology, hydrodynamics and sedimentology.  This is unlike other forms of marine energy which can be built and commissioned incrementally. This may be a potential route for tidal stream pending progress in the necessary technology to make adaptive management feasible and sustainable.


Tidal barrage

Tidal barrages have long been proposed as a way of harnessing the large tidal range of parts of the west coast of the UK, particularly on the Severn Estuary which has one of the biggest tidal ranges (difference between low and high tide) globally. Conventional barrages and lagoons work by building an impoundment to create a difference in water level across the structure to power turbines.  They can be used to generate energy on rising tide, the ebbing tide or both depending on how they are configured. The greatest potential for tidal range energy overlaps with many of our most important wintering bird sites – e.g. Solway, Morecombe Bay, Mersey, Wyre, Dee, and Severn Estuaries.


Significant projects would be very large-scale interventions in coastal and estuarine systems with profound environmental effects which may extend beyond country borders.  Significant ecological impacts would likely include:

An example of conflict between wildlife and tidal ambition is the Severn Estuary. Its mudflat and saltmarsh habitats are natural carbon stores that support over 80,000 wintering waterfowl and wading birds. In its waters are 110 species of fish including seven migratory species which are internationally important not just in the Severn but in the designated rivers that flow into it.

Our written evidence to the Welsh Affairs and Business, Energy and Industrial Strategy Parliamentary Committees in 2018 (annex 4) included the following:

The DECC Severn Tidal Power Feasibility study and the Welsh Government’s Habitat Regulations Assessment both found that compensation for a large scale tidal lagoon would be very challenging. We note that in the absence of reliable and adequate compensation it may not be possible for even a single large scale lagoon to comply with environmental standards. A fleet of lagoons would be even more challenging. On the evidence currently available it is questionable whether significant tidal lagoon developments can be delivered in compliance with environmental legislation.

Whether or not SBTL proceeds, more innovative forms of tidal range technology may be under development with potential for lower cost and lower environmental impact. Finding a better tidal range technology may be the only solution to realising the potential in a way that is environmentally sustainable. This was outside the scope of the Hendry Review. We see the need for Government to encourage or undertake a review of emerging and innovative tidal range technologies. The DECC Severn Tidal Power Feasibility Study of Embryonic Technologies should be re-visited and extended to cover any newly emerging concepts. This should include consideration of different lagoon configurations, turbine technologies and other concepts.

We question whether current lagoon technology can be scaled up as envisaged by the Hendry Review while still protecting our marine and coastal wildlife. Evidence shows that a fleet of tidal lagoons will have large scale and complex wildlife impacts. The Welsh Government’s own assessment of a policy supporting multiple tidal lagoons around Wales could not rule out adverse effects on 70+ of the most highly protected wildlife sites (SPA, SAC and Ramsar). This includes sites in all four countries of the UK and some in France and the Republic of Ireland highlighting the importance of co-operative approaches across geo-political boundaries.

The economics of conventional tidal lagoons and barrages is relatively well understood these being established technologies. Consequently, the potential for reducing costs through widespread adoption is much more limited than for more innovative technologies.  This was acknowledged by the Hendry Review which suggested that committing to a suite of tidal lagoons might result in cost reductions of only 10%. Tidal lagoons and barrages have in no way followed the cost reduction success of other renewables including fixed offshore wind, onshore wind and solar. Tidal projects have significantly high upfront capital costs and while they may operate for a long time, operational costs are only low if they operate as claimed[1].

In 2018, Westminster Government determined that tidal lagoons are not good value for money and announced that it would not support any of the programme of six lagoons promoted by Tidal Lagoon Power (TLP) including Swansea. In many ways this reinforced the position of the previous Westminster Coalition Government, who concluded the 2006-10 review of Severn tidal power by saying that there was no strategic case for government to support a tidal power project and it would not reopen the debate unless or until the strategic context changed (i.e. if the need grew or the cost of technology reduced). Since then the debate has reopened and closed again.


Tidal stream

Tidal Stream energy requires a strong tidal flow. Areas with such conditions have higher nutrient concentrations. As a result, they also attract lots of marine wildlife. The potential impacts to seabirds from tidal stream energy devices include collision, disturbance (i.e. noise and/or human activity that causes birds to move away - displacement), habitat loss, and loss of access to preferred foraging areas (displacement). These impacts can cause both lethal or sub-lethal effects, such as death due to being struck by moving parts or reduced breeding productivity through displacement from feeding areas.

Mathematical modelling is currently the most commonly used approach to assess the risk of collision of marine animals with tidal stream devices. However, little validation of the modelling techniques or the assumptions that underpin them has been carried out due to the lack of empirical data and urgent research is needed in order to do so. Monitoring and research are vital to increase our understanding of how wildlife interacts with, and is impacted by, tidal devices. This evidence base would provide much needed clarity on how and if this technology can be deployed, increasing certainty for developers and investors. However, the necessary monitoring techniques are in their infancy and need to be further developed and their effectiveness tested.

Adaptive management (sometimes called ‘learning by doing’) has been proposed as a way of enabling developments to proceed in the absence of certainty.  This approach envisages that feedback from monitoring could be used to adjust or stop development. However, without the necessary and acceptable level of monitoring and research, adaptive management cannot be delivered and should not be used to justify potentially ecologically damaging developments. To determine whether tidal stream energy is an ecologically sustainable option for phased commercial scale development, governments, statutory bodies and industry need to adopt a cautious approach.

As highlighted, further research to develop monitoring techniques and to build the evidence base is needed. Following this, technologies could be tested at an appropriate scale, in well-sited demonstration sites. The RSPB recommend a pause on commercial deployment at scale until we have learnt (from initial phases in a Demonstration Zone) whether, where and how tidal stream resource can be used.

The RSPB’s Energy Vision

The RSPB’s 2050 Energy Vision Report published in 2016 shows how a transition to sustainable energy can be made in harmony with nature. This depends on the choice of technologies and on proper consideration of environmental impact in their siting and design. This found that we can meet our energy and carbon targets with less risk to wildlife and nature than with large scale tidal lagoons. But tidal range energy remains a compelling idea. With partners we published the Severn Vision which includes a goal of developing in harmony with nature, tidal renewable energy. The challenge then is whether there could be a solution that is value for money and environmentally sustainable.

The technical report envisages that it would be unlikely that any shore to shore barrage could be deployed in an ecologically sustainable way. It considered that tidal lagoons might be possible without significant ecological risk depending on the location calling for a precautionary approach until the impacts are better understood.  Should this tidal lagoon technology be progressed, a phased deployment is recommended to gather an evidence base prior to large scale development.


Cumulative impacts – an offshore wind example

Offshore wind can impact seabirds in a variety of ways during construction and operation. These include collision, disturbance, direct habitat loss, blocking important flight pathways (barrier effects) and loss of access to preferred foraging areas (displacement). Ultimately these impacts, individually or cumulatively via multiple windfarms and other activities and developments, contribute to increased mortality and reduced breeding success for globally important populations.

The threat of cumulative impacts on seabirds from offshore wind has been acknowledged across the sector and by the UK Secretary of State.  We have assessed the population impact of built and consented offshore wind turbines and found that they can pose considerable risk to threatened species such as kittiwake, which is predicted to experience a 21% decline from collision impacts alone. This is of even greater concern set in the context of existing seabird declines, which for kittiwake have been particularly devastating: since 1986, the UK kittiwake population has fallen by 70% due to declines in breeding success and survival[2]. Without urgent changes to the way we plan this technology and manage our seas, the threat will increase with each new offshore wind development in our seas.

Tidal is indeed a very different technology, but the situation in our seas is critical. Each new pressures from development increases the threat to nature and must be considered in this context.


The RSPB’s overarching recommendations marine renewables

In addition to the technology specific points raised above, we have overarching recommendations for the upscaling and accelerating of renewables deployment. In an increasingly busy marine environment, space must be made for the right renewable technology; both in terms of the physical space needed for infrastructure (including cabling) and in relation to the interrelated pressures threatening our marine environment. It is the view of the RSPB that the sustainable and timely development of low carbon renewables will only be possible if informed by evidence-based, strategic, government led marine planning which prioritises and integrates climate and nature objectives and is delivered alongside coordinated action to restore and ensure the resilience of our shores and seas. Our recommendations are therefore set in this context but do recognise that there are steps which can and should be progressed by TCE in the early 2020s. These steps would improve the trajectory of offshore wind and – if mobilised in time – have the potential to minimise the ecological impact of reaching 2030 targets. 


  1. Research and monitoring

One of the significant challenges to upscaling and accelerating offshore renewables deployment (tidal stream and floating wind) is the absence of a robust evidence base. The lack of data on marine species and impacts creates uncertainty, which increases consenting risk and the potential for project delays. Nature and the energy sector would both benefit from increased certainty achieved through new research programmes and – in the short-term – making the best possible use of existing monitoring mechanisms and data. 

1.1 Mobilising new research and monitoring

Research and monitoring must be mobilised at scale to provide a robust evidence base on how wildlife uses our seas and interacts with renewable technology. Significant evidence gaps remain in relation to the year-round distribution of seabirds across UK waters and in relation to foraging behaviour during the breeding season (i.e. where they go) as well as – for example – dispersal between colonies and juvenile survival. These evidence gaps must be filled to increase certainty and identify the least damaging areas for offshore wind development. Research and monitoring also needs to be utilised to address cumulative impacts on marine wildlife, including robust research in to whether viable compensation measures exist for those species and habitats most likely to be adversely impacted. Such work should also consider other marine wildlife and habitats, including cetaceans and fish and should receive priority support through initiatives such as the Offshore Wind Evidence Change Programme (while wind focused, there may be evidence which is transferable to offshore renewables more widely).

1.2   Existing data and standardised monitoring of development

In addition to launching new research programmes, efforts should be made to make the best use of existing data sets. A primary source of information on seabirds is held by developers themselves and the requirements for this are set by the appropriate authority. To help address uncertainty in the short-term we suggest:

-          TCE and planning bodies seek to make better use of the existing data by increased and timely sharing. This could include a commercially sensitive release and pooling of developer data.

-          Giving serious consideration as to how leasing and consenting conditions could be amended in future to support enhanced used of existing data, including agreeing on the standards of data collection and analysis to facilitate increasingly robust assessments and comparisons

We also strongly urge the use of existing seabird tracking studies (please see section 2.4) to inform TCE and planning bodies consideration of ecological constraints and the identification of sensitive areas where there is a much higher risk to nature from offshore renewables development. This is highly relevant to ambitions for tidal expansion in Wales.

1.3 Adaptive management

Robust monitoring techniques are urgently needed to understand how tidal stream devices affect wildlife. Once these monitoring techniques have been developed, small initial phases of the proposed development could be used to find out whether the technology can be deployed at commercial scale with consideration given to our points raised above.


  1. Strategic marine planning 

To deliver on 2050 net zero targets, decarbonisation must be supported by a strategic and spatial view of how increased renewables infrastructure, other marine uses and nature can be accommodated in increasingly busy waters. While Scotland has recently adopted a new Sectoral Plan, marine planning in England and Wales does not take a strategic spatial view and is therefore limited in its ability to tackle climate change by supporting an energy transition in harmony with nature. In England, marine plans – even those more recently in draft during 2020 – make no reference to net zero and fail to identify or make any assessment new areas for renewables expansion. Marine planning in Wales similarly lacks strategy and specifics. The absence of strategic marine planning jeopardises the UK and devolved administration’s environmental commitments and net zero.


2.1 Government led strategic planning

All offshore and coastal renewable energy deployment must be informed by evidence-based strategic plans which prioritise and integrate climate and nature and are led by the relevant government. These new plans should support accelerated deployment by addressing environmental impacts from development at the outset and direct renewable infrastructure to the most suitable locations. To deliver the necessary energy transition, marine plans should consider and assess all uses of our seas to optimise delivery on priorities and maximise co-location.


In the interim period, TCE in England and Wales – must deepen their consideration of biodiversity and seek to optimise seabed space for sustainable offshore renewables. This should include collaboration with stakeholders to identify the best possible routes to delivering technology already in the pipeline for 2030 and prioritising seabed space for decarbonising in harmony with nature. Failure to act now will have ramifications for deployment in the 2030s and beyond.


2.2 Addressing ecological impacts to de-risk investment

The CCC have highlighted the significance of private investment in delivering the recommendations of the 6th Carbon Budget. The current approach to planning renewables technology essentially defers tackling ecological issues to the project level locking developers into sites with unresolved environmental impacts and risking delays to projects at various stages of planning including in relation to meeting the Habitat Regulations tests. This is relevant to tidal which seeks to operate in the same sea space without a robust evidence base and, given the scale of development and existing threats, is likely to face the challenges of cumulative impacts and compensation.

We have now permanently entered a phase where we will have to address both the need for and, critically, how best to compensate for the damaging impacts of offshore wind on seabirds and other marine wildlife. Getting this right is vital if we are not to leave the impacted species and habitats worse off as a result of poorly implemented or inappropriate compensation. Compensation must address the ecological requirements of the impacted species or habitats, be properly secured and implemented, with effective monitoring. Compensation for seabirds is however a huge challenge. It remains completely untested and unproven. Planning and consenting systems which operate project by project increase developer competition rather than establishing a level playing field which could facilitate joint problem solving and the delivery of compensation at a strategic ecosystem level.


The aim should be to use the robust, evidence-based approach to strategic planning described above to ensure decisions on future deployment genuinely avoid damaging impacts on marine wildlife and thereby the need to compensate at all. This is the best way to ensure future offshore wind is carried out in harmony with nature.


2.3 Offshore transmission networks

The current approach to designing and building offshore transmission was developed when offshore wind was a nascent sector and industry expectations were as low as 10GW by 2030. In the context of increasingly ambitious targets for offshore wind and aspirations for tidal development, constructing individual point to point connections for each project may not provide the most efficient approach and could become a major barrier to delivery given the considerable environmental and local impacts, particularly from the associated onshore infrastructure required to connect to the national transmission network. The consenting of all infrastructure and activities must be considered within one transparent and strategic planning system. Such an approach would provide routes for increased efficiency, colocation and reductions in environmental and societal impacts.

The RSPB considers that continued use of individual point-to-point, or radial, links may not be the best outcome for consumers in the future as generating capacity increases. Retaining this approach is also likely to increase pressure on coastal connection points with both social and ecological implications.

2.4 Space for nature

In 2020, the RSPB’s scientists produced new maps identifying, for the first time, the location of marine hotspots for some of the UK’s most threatened seabirds, based on tracking data from kittiwakes, guillemots, razorbills and shags from UK colonies during the breeding season. The largest single marine SPA in the UK – the Outer Thames Estuary SPA – covers an area of 3,924 km2. However, the new analysis shows that many hotspots are larger than this, and under some of the mapping techniques exceed the total area covered by all current marine UK SPAs. The mapping reveals the importance of the Scottish coast (particularly the East coast) for kittiwakes, guillemots and razorbills. Important hotspots for these species were also found around the Pembrokeshire coast (Wales), Rathlin Island (Northern Ireland) and the Yorkshire coast (England).

The results highlight the importance of large areas of UK waters for breeding seabirds demonstrating the urgent need to extend the protection and effective management of these areas, alongside strategic, spatial marine planning and standardised industry-level regulations, to protect wide-ranging seabird species particularly in the context of increased efforts to decarbonise energy generation in UK waters.


3. Conservation to secure the long-term recovery and resilience of nature

Alleviating the wider pressures on nature is an essential component of reconciling ambition for increased renewables deployment and the associated threats to nature. Collaboration and investment is needed from governments, TCE and industry to to support the delivery of meaningful conservation at scale if ambitious and accelerated renewables deployment is to be achieved.


3.1 Reversing seabird declines and boosting resilience

Given the continued decline of UK seabirds, and the drivers to achieve Good Environmental Status, it is clear we need a major recovery plan for seabirds, prioritising direct action to halt and reverse the continuing decline where we can, increasing population resilience and investigating the reasons for declines where it is unknown. This should include:

3.2 Nature-based solutions

Transforming the deployment of offshore energy and associated infrastructure can also contribute to the delivery of net zero by preventing damage to coastal and marine ecosystems which – while healthy – can be extremely efficient carbon sinks. Important habitats for storing carbon in our seas and shores include saltmarsh, mudflats, seagrass beds and subtidal sediments.  These essential, nature-based solutions can be extremely efficient carbon sinks – if undamaged by development and other human activities. Increased pressure on the seabed and coasts, including multiple point to point transmission networks, could be alleviated through a more strategic approach which optimises use of our sea space for climate and wildlife including nature-based solutions.


4. Collaboration and innovation

Fundamental to achieving renewables deployment at scale in harmony with nature – including successful demonstration projects – is increased collaboration. A sustainable energy transition must be facilitated by improved collaboration between stakeholders and governments, between UK government and devolved administrations and between the UK and other countries including across the North Sea and on a global scale. This in turn will aid plan making, research and development and a joined-up approach to conservation.


Recommendations for the EAC

The RSPB strongly supports the EAC’s efforts to inform the UK’s low-carbon energy mix through the Technological Innovations and Climate Change inquiries. We would like to take this opportunity to highlight some areas which the EAC may wish to consider for investigation in 2021.


Improving the trajectory for offshore energy

Offshore energy can be a UK success story. But to be an essential part of building an economy that works for climate and nature and efforts to reach net zero, the conflict between infrastructure expansion and cumulative impacts must urgently be addressed. Acting on these recommendations will improve the pathway for accelerated and sustainable deployment of the right technologies in the long-term and has the potential to deliver benefits in the short-term if mobilised in time (i.e. for tidal stream to inform developments currently under consideration, for offshore wind to inform Round 4 in England and Wales,). This is vital to remove the jeopardy the current approach places on nature and net zero and to support the investment and innovation needed to make emerging technologies part of the future energy mix.

December 2020


[1] Sedimentation - whether sediments behave as modelled and predictions about level of (additional) dredging that is required prove accurate.

[2] Hayhow DB, Ausden MA, Bradbury RB, Burnell D, Copeland AI, Crick HQP, Eaton MA, Frost T, Grice PV, Hall C, Harris SJ, Morecroft MD, Noble DG, Pearce-Higgins JW, Watts O, Williams JM The state of the UK’s birds 2017. The RSPB, BTO, WWT, DAERA, JNCC, NE and NRW, Sandy, Bedfordshire.