Renew On Line (UK) number73
|Extracts from NATTA's journal
Renew, Issue 173 May-June 2008
|Welcome Archives Bulletin|
2. Wave and Tidal- ‘slow progress’
Lots of wave and tidal projects are currently under test at various scales, many of them queuing up at EMEC in Orkney. But also down south. Trials of Essex-based Trident Energy’s wave generator off the Suffolk coast are following tests on a small model. The company said the trial would be conducted about 5 miles off Southwold and would run for a year. It added that the eventual full-scale wave farm platform will probably be located further out to sea where their was more wave energy. The Trident system uses direct energy conversion rather than mechanical gearing, hydraulic or air compression systems to run a motor. The wave motion captured by floats placed in the sea which directly drive a linear generator- the bobbing action moves the armature coils though a stator thus electromagnetically inducing a current. They say this should make it cheaper and easier to maintain.
However, a new report from the Government’s Renewables Advisory Board (RAB), looks at progress with developing and demonstrating wave and tidal stream power and says that that, whilst the long-term prospects remain promising, progress has been slower than hoped. A key concern is that the governments support scheme, the £42m Marine Renewables Deployment Fund (MRDF), has not yet actually provided any support, because no projects have been able to meet the eligibility criteria- they must have three months successful operation at sea before they can get funded. The RAB report makes dismal reading, in effect trying to explain this away: ‘the MRDF is fundamentally a sound scheme. It, in itself, is not a failure, but the R&D process has failed to supply the technologies that the MRDF was established to support.’ So the scheme is fine it’s just the technology isn’t yet ready!
The reasons offered are that ‘The technical challenges, particularly of operating in a marine environment, are great and perhaps more difficult than originally expected. Also, there has been some over-optimism in the industry, leading to raised expectations. R&D projects are taking longer and costing more and have not yet established the current cost of energy of wave and tidal stream.’ The result is that ‘projects have not yet reached the point where they are ready for demonstration in a fully commercial environment’, although ‘some technologies are expected to achieve this within the next year’.
RAB conclude that the MRDF was in effect started too soon, but they do not suggest it be scrapped- although it might be improved to make it more accessible when devices are ready. The governments decision to provide double Renewable Obligation Certificates for marine renewables was welcomed, as reflecting an awareness that costs will be higher and more support was needed than had earlier been expected. But the basic message is that it will all take longer than hoped. The three month eligibility rule was defended as necessary to ensure viable projects, and the MRDF’s offer of a mix of capital grants and revenue support, rather than just capital grants, was seen as important to reward successful devices. The RAB appendix however does mention Scotlands £13m Wave and Tidal Energy Support Scheme, launched in 2006, which has simply offered capital grants- £10m so far to 9 projects. But it notes that, like the MRDF, Scotlands independent Marine Supply Obligation has yet to get going- it’s been set at zero awaiting commercial projects. See p.4 RAB concludes that despite the slow progress, ‘the UK is still regarded as the world-leader in this field’ and it suggests some improvements to R&D support to help speed things along- it notes that the MRDF has already provided £6m for the Wave Hub off the N. Cornwall coast, and talks of better collaboration with academic research, like the Supergen Marine initiative. One of the aims of new Energy Technology Institute is to accelerate marine renewables. Let’s hope they can get things moving.
Tidal Power review
While small projects are to get double ROC’s (see Section 3 below), large tidal barrages and lagoons in the Severn will be looked at in a new BERR feasibility study which will analyse the potential environmental, social and economic impacts of the possible projects. It will enable the Government to decide whether and on what terms it could support a tidal power project. BERR says ‘One of the possible technologies, a Severn Barrage, would harness the power of the Estuary using the proven technology of a hydro-electric dam, but filled by the incoming tide rather than by water flowing downstream. Such a project, as the recent report from the Sustainable Development Commission confirmed, has the potential to generate some 5% of UK electricity from a renewable British source.’
Secretary of State John Hutton said: ‘The potential scale of this project, and the impact it could have for both securing energy supplies and tackling climate change is breathtaking. The Severn Estuary has some of the best tidal potential in the world and could more than double the current UK supply of renewable electricity, and contribute significantly to targets for renewable energy and CO2 emissions reduction. We must understand the cost and the impact that a project of this scale could have, not least the environmental, social and economic effects. But the need to take radical steps to tackle climate change is now beyond doubt. Tough choices need to be made. We must consider all our low carbon energy options.’
Finance & Environmental Assessment
The study will include a Strategic Environmental Assessment, and will last ‘about 2 years’, concluding with a ‘full public consultation’ in early 2010. The study will be a carried out by a cross-Government team, also involving the Welsh Assembly and the SW Regional Development Agency, with ‘expertise from a number of organisations and engaging stakeholders and the public at large’. Building on the work of the Sustainable Development Commission and earlier studies, the new study will:
* assess in broad terms the costs, benefits and impact of a project to generate power from the tidal range of the Severn Estuary, including environmental, social, regional, economic, and energy market impacts;
* identify a single preferred tidal range project (which may be a single technology/location or a combination of these) from the number of options that have been proposed;
* consider what measures the Government could put in place to bring forward a project that fulfills regulatory requirements, and the steps that are necessary to achieve this; and,
* decide, in the context of the Government’s energy and climate change goals and the alternative options for achieving these, and after public consultation, whether the Government could support a tidal power project in the Severn Estuary and on what terms.
Lagoons and Barrages
The feasibility study will consider barrages and lagoons, but not tidal stream technologies. BERR notes that technologies ‘must comply with a wide range of environmental legislation, including the EU Habitats and Wild Bird directives. The Severn Estuary is of National, European & International nature conservation significance- and so has been afforded the corresponding levels of legal protection. It is designated as both a Ramsar Site and Special Protection Area (SPA) under the EU Habitats Directive and is in the process of being designated as a Special Area of Conservation (SAC). The Estuary also comprises a series of Sites of Special Scientific Interest (SSSI).’
Metrotidal Ltd has proposed a 4.75 sq.km tidal lagoon in the Thames estuary, coupled, in a £2-4bn project, with a tunnel crossing and tidal surge barrier between Medway & Canvey Island.
Welsh Tidal Farm
Npower Renewables and Marine Current Turbines (MCT) have formed a new company, SeaGen Wales, to develop a 10.5 MW tidal farm using 7 of MCT’s 1.5MW SeaGen turbines, sited in 25 m deep open sea in the Skerries area off the coast of Anglesey, N. Wales, where there is a 5.4m tidal range and a 3.19 m/s mean spring current. The £20-30m project could be operational in 2011, assuming consents are forthcoming.
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