Let's start a European tidal lagoon industry

Seeing is believing. The concept of the Tidal Lagoon Swansea Bay can only be understood if you see it before your eyes, so before you read any further, take a look at the project film (at the bottom of this page).

As you can see in the film, the Tidal Lagoon Swansea Bay is an ambitious project. It involves building a six-mile U-shaped wall which includes a 250 metre long turbine unit housing 16 turbines of 20 MW each, harnessing the huge tidal range off the Welsh coast. The lagoon would also be used for cultivating fish, sports events and cultural displays.  The total investment would be in the region of £1 billion. It would be a world’s first.

So how realistic is it?

Vision
Wave and tidal power have long been a promise of the future. They include a range of different techniques at different stages of development. Wave power is still in its infancy. Tidal stream power, in which underwater turbines are used to harness the power of moving water, has also yet to be demonstrated at scale.  The UK, Canada and the US are planning tidal stream demonstration projects in the next few years.

The tidal barrage on the other hand – a dam-like structure in which a turbine is used to generate electricity as the water moves in and out due to tidal forces – is  a mature technology. The La Rance barrage in northern France has been in operation since 1966.

Ocean Energy Europe, the trade association promoting both wave and tidal power (plus technologies to generate power using differences in temperature and salinity of seawater), estimates in a 2013 Vision Paper that there could be no less than 100 GW of  ocean energy off Europe by 2050. That would basically take care of all of our electricity needs! The European Commission has embraced the industry’s vision.  But it is still just a vision.

Wildlife
The current reality is a little different. The UK government offers wave and tidal projects a “strike price” (a guaranteed price) of £305/MWh, the highest of any renewable energy sources (offshore wind gets £155/MWh, onshore wind £95/MWh), but few projects have materialised. According to a new report from Bloomberg New Energy Finance, by the end of the decade global installations of tidal stream and wave power will amount to no more than 148 MW and 21 MW respectively. “Tidal stream and wave power companies continue to face huge challenges”, says the report.

A number of wave power companies have failed or are faltering. In the UK there is only one small tidal stream device in place – the 1.2 MW SeaGen owned by Siemens and Marine Current Turbines in Northern Ireland.  However, just last week, on 21 August, it was announced that the Scottish government is giving £20.5 million, and the UK government £10 million, to MeyGen to begin development of a 398 MW tidal stream array in the Pentland Firth, off the north coast of Scotland, the largest tidal stream project in the world. The grants are for phase one, construction of 6MW. Scaling this up will require further financial support from public bodies.

First Minister Alex Salmond said that Scotland could be the Silicon Valley of marine renewables.  In response, UK Energy and Climate Secretary Ed Davey said: “The project…shows what can be done when the UK and Scottish Governments work together to provide a lasting benefit for the people of Scotland.”. There is an obvious political impetus behind the current support for MeyGen. Whatever the result next month of the Scottish independence referendum, the same level of support cannot be guaranteed.

The Bloomberg New Energy Finance report does not cover tidal range power, but progress in this sector has also been slow. Debate in the UK has centred around the Severn Estuary, between England and Wales, which has the second highest tidal range in the world (after the Bay of Fundy in Canada). There have been discussions about, and committees on, using the Severn to generate electricity since 1925.  But nothing has been done.

The Severn barrage has had strong supporters, but also strong opponents. The Severn estuary is rich in wildlife and has many important habitats.  It would be extremely challenging to construct a barrage without infringing the EU Habitats Directive and Wild Birds directive. The current UK government said that it would be prepared to consider a barrage, but without subsidy. So no financial support level for tidal range projects has been announced.

Cheaper
However, building a barrage is not the only way to use tidal ranges to generate electricity. It is also possible to build a lagoon, and then use the incoming and outgoing tide to turn turbines in the lagoon wall. Lagoons can be located to avoid the most sensitive habitats, so are more flexible than barrages.

What is the potential of tidal lagoon technology, how much does it cost and what would be its environmental impacts? These questions are difficult to answer with any certainty, since no tidal lagoon has yet been built, anywhere in the world.

The 320 MW Swansea Lagoon, for which Tidal Lagoon Power has submitted a planning application to the UK government , would generate a similar amount of electricity to a 140Mw offshore wind farm. That’s smaller than existing and planned offshore wind projects. But Swansea would be a pilot – and the UK pilot for offshore wind was just 4Mw.

If the pilot works as anticipated, the company plans to build several more in UK waters: in the Severn estuary, off north Wales and off north-west England. These lagoons’ capacity would total 15 GW, generating renewable energy at entirely predictable times.

Even the first lagoon would be much cheaper to construct than the first tidal stream plant. It would require a support level of £168/MWh, compared to the offered £305 for tidal stream. The lagoon support would be slightly higher than the level of support currently offered to offshore wind (£155). But future lagoons would be larger, and increased scale would require a lower level of financial support. A March 2014 report by consultants Poyry calculates that the first three lagoons would require a volume-weighted average support level of £111/MWh – well below the current level for offshore wind and only just above the level for onshore wind.

The Swansea Bay project is not only relevant for the UK. Tidal lagoons have the potential to make a significant contribution to Europe’s economy as well as to its climate and energy policies. Countries like France and Portugal could also use tidal lagoons. The supply chain could be European. And the technology could be exported to China, India, South Korea, Canada and the US.

What impact would tidal lagoons have on wildlife? Nobody knows exactly, because one has not been built. The UK’s Sustainable Development Commission published a good report on tidal energy in 2007. Having assessed the large impacts of a Severn barrage on fish, birds and habitats, this report points out that solid evidence on the biodiversity impact of lagoons will only be available once a lagoon is built, so it encourages the UK government to get one built.

Support
Tidal Lagoon Power has carried out an extensive Environmental Impact Assessment (EIA) for its Swansea project, running to 4,000 pages . This notes that “the project site does not overlap any ecologically protected sites designated for marine features, [but] there are two sites that support birds which feed in the intertidal areas…In addition to this, there are a number of important ecological features within Swansea Bay as a whole.” The EIA finds that the project will not have significant effects on any of these.

Harbour porpoises and grey seals could be disturbed during construction, but the company will follow official guidelines to minimise such disturbance. The Lagoon will not physically block access to the mouths of any rivers. There will be no major impact on shellfish (which have declined seriously in Swansea bay already) or other fish species. On birds, the EIA notes that the project would result in the loss of intertidal and subtidal habitat which is used by several coastal bird species for foraging and roosting, but alternative habitats are available to birds within Swansea bay. The company will avoid construction during the main wintering bird period (October-March), and also provide new fish spawning grounds.

A tidal lagoon in Swansea bay would have the added benefit of reducing the risk of flooding in the city of Swansea. This, together with the proposed new sailing and watersports facilities, may be why the proposal was supported by 86% of the 2,600 residents who responded to the statutory consultation questionnaire which the company distributed in July/August 2013. Such a high level of public support is very unusual for any proposed new development in the UK.

Private investment will be used to develop the tidal lagoon. Equity shareholders in the development phase include the local community, Tidal Lagoon Power management, high net worth individuals and corporations (including Good Energy). Local businesses are very supportive. At a public planning hearing at the city’s Brangwyn Hall in July,  Robert Lloyd Griffiths of the Institute of Directors (Wales) said the idea was “innovative and influential” while Tony McGetrick of Tourism Swansea Bay said that most of the group’s 400 members were “overwhelmingly in favour” of the lagoon. Only Swansea University raised some critical questions about the project.

In my view, we have here a proposal for a new technology which would improve energy security, help control climate change, create a new sector in Europe’s energy industry and which local residents actually want in their back yard. The European Commission, and the British government, should not let this opportunity pass.

Stephen Tindale is an associate fellow at the Centre for European Reform.