David Fowler reports on TIGER, an ambitious European project that promises to put the UK at the forefront of the tidal energy sector
Renewable energy in the shape of wind and solar power provides an increasing share of the UK’s energy mix, reaching 40% in the third quarter of last year. So far, however, tidal power has not made significant inroads into the market.
Over the next three years, the Anglo-French Tidal Stream Industry Energiser Project, or TIGER, is aiming to demonstrate that tidal stream energy is a maturing technology which, with a revenue support mechanism to allow significant deployment, could reduce its costs to a competitive level with nuclear power.
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Last autumn the €46.8m (£38.9m) project was awarded €28m (£23.3m) from the European Interreg France (Channel) England programme to install up to 8MW of generating capacity at a number of sites around the south coast of England and the north of France. The award makes it the biggest ever Interreg project.
The programme seeks to gain experience in installation, operation and maintenance of tidal power, demonstrate cooperation with an Anglo-French supply chain, and disseminate the results to help accelerate the commercialisation of tidal stream energy.
Tidal stream energy generates electricity from tidal currents using structures resembling underwater wind turbines, as opposed to tidal range energy projects such as La Rance in France and the proposed [scrapped] Swansea tidal lagoon, which use dams or barrages to impound water and then control its release through turbines.
The TIGER consortium was assembled and is being project managed by the Offshore Renewable Energy Catapult, which has a regional office in Hayle, Cornwall. ORE Catapult sector lead for wave and tidal energy Simon Cheeseman explained that the withdrawal of government subsidies in 2018 left tidal power deployment in limbo. “The UK is at the forefront of wave and tidal technology development, but in the UK there’s no revenue support mechanism to enable developers to provide competitively priced electricity,” he said. “Tidal power has to compete in Contracts for Difference auctions but it’s not competitive because it hasn’t got the scale.”
Renewable UK has been lobbying for the reinstatement of some sort of revenue subsidy. In 2018, ORE Catapult published a report, Tidal Stream and Wave Energy Cost Reduction and Industrial Benefit, which set out how tidal power could meet three tests for the viability of new forms of renewable energy set out in the government’s clean growth strategy. These are that it should have a clear cost reduction pathway; that the UK could develop world-leading technology in a global market; and that it would reduce carbon dioxide emissions.
The report argued that costs would be driven down by “learning through doing” – gaining genuine experience of installation and operation; and from economies of scale; standardisation of components; working with the supply chain to reduce costs; and innovation offering improved performance. This would provide increased confidence in the technology to bring down the cost of capital and insurance.
The learning through doing aspect is important. Because tidal power equipment has to be installed, operated and maintained in the sea in areas where currents are strong, “the costs, risks and difficulties rise exponentially”, said Cheeseman. Though test rigs can be set up on land, eventually systems need to be tested in the water.
The report also made the point that the investment in the sector would bring an economic boost to coastal communities where traditional industries such as fishing had declined.
“In the report, we were able to demonstrate a clear cost reduction pathway, once we reached 1GW of deployment, to take tidal stream energy to £90/MWh, which would be competitive with nuclear,” he said,
Being competitive with nuclear could be significant. Tidal power is unique among renewables in being predictable. Tides and current flows are published in advance. “As a developer, if you put a turbine in the English Channel, you can calculate with a high degree of accuracy what you will get out of it,” Cheeseman said.
The cost reduction pathway has been widely acknowledged, and TIGER was developed as a way to demonstrate it. In France, the sector faced similar difficulties and there was scope for synergies. In the UK, councils and Local Enterprise Partnerships around the south and east coasts of England as far as Norfolk were interested in investing in the technology. ORE Catapult became involved to pull together a consortium (see box) and continued as project manager.
The UK side is structured around the Marine Energy Council, which brings together all the leading tidal and wave power developers, and as part of TIGER is hoping to create a French equivalent.
The overall objective of the project is to provide evidence that tidal stream energy can take the first steps along the cost reduction curve; to develop a UK/France supply chain, and to work with it to identify critical areas where cost reductions are necessary. These include blade design and manufacture; pitch control systems; subsea cables and connectors; installation methods; and improvements in overall system reliability.
Interreg is keen to see installations at different sites, both tidal channels and headlands, and with different types of turbine. Accordingly, the project will demonstrate floating devices as well as large and small turbines fixed to the seabed, and more novel devices such as that developed by Swedish company Minesto, which resembles a small aircraft or glider with a propeller/turbine. Tethered to the seabed, the glider travels in a figure-of-eight pattern, pushing the turbine through the water at a relative speed faster than the underwater current. This allows it to operate in low tidal flows where a horizontal axis turbine would be inefficient.
Because the Interreg programme is due to end in March 2023, the sites chosen had to be already operational, or close to gaining consent.
In the UK the Ramsey Sound site, off Pembrokeshire in Wales, is being revitalised. It was the site for Tidal Energy Ltd and was a fully-fledged generating site until its Delta Stream turbine developed problems and the company went into administration. As part of the project, TIGER will be removing the turbine and examining the reasons for its failure.
The site will be operated by Cambrian Offshore South West; a new turbine of potentially up to 1MW will be installed but a decision has yet to be made about its type.
Also in the UK, potential sites in the Solent region are being examined.
In France, Paimpol-Bréhat is an EDF Hydro owned open-sea test site where a turbine was installed and tested last year by Hydroquest. The site will be upgraded to accept a broader range of turbine technology. It is expected that a 100kW Minesto glider will be installed as part of the TIGER project.
At a new site in Morbihan, Brittany, French turbine developer Sabella working with Morbihan Energie will install and operate two 250kW turbines. Sabella regularly installs turbines for testing on the French island of Ushant.
At Raz Blanchard, north of the Channel Islands, Hydroquest aims to complete consenting for a 10MW pilot turbine farm. Normandie Hydrolliene, a joint venture between Edinburgh-based SIMEC Atlantis Energy and the regional development agency AD Normandie, will also aim to complete consenting for their 1.5MW horizontal-axis three-bladed turbine as the first phase of a commercial tidal project of between 5 and 20MW. Atlantis’s MeyGen project in Orkney went operational in 2018. Hydroquest will install a vertical blade turbine, allowing comparison of installation, maintenance, power generated and cost of operation.
The UK’s Orbital Marine Power, which has been testing its turbines at the European Marine Energy Centre in Orkney, will look at tailoring its design and the economics of deployment at the different TIGER sites.
In general, installation of the turbines does not require major construction operations. The seabed-mounted type stand either on steel gravity structures or simple piled foundations, and the driveline and generating equipment are preassembled and contained in a nacelle. An export cable takes power to the shore, where some horizontal drilling under the beach for the cable is required.
Installation challenges arise because the turbines have to be installed where currents are strong, so most work has to be done at slack tide, which lasts only 30-40 minutes. Offshore work will be done by remotely operated subsea vehicles to avoid the use of divers, but they can only work at low tidal velocities. Further development of installation and support vessels that can operate in shallow waters with high flows is another area to be investigated with the supply chain.
Numerous academic partners in the consortium will be evaluating the data emerging from the project and measuring the performance of the installations. The results will be disseminated by ORE Catapult through a series of workshops, conferences and reports.
In addition to demonstrating the technology’s maturity for the UK market, the TIGER project is also hoping to open up export markets, particularly for off-grid island communities which currently depend on diesel generation.
Tidal power has had false dawns in the past, but Cheeseman is confident the project will succeed, not least because of its broad-based nature involving some of the leading developers, engaging with a knowledgeable supply chain and expert marine energy academics from universities in the two countries.
“We’ve got the cost reduction curve broadly accepted,” he said. “We’ve got the technology. It’s all been tested at independently so we know it works. This is about collecting hard evidence to support a cost strategy and putting it into practice.”
Consortium Partners
TIGER comprises 18 partners from across the UK and France spanning turbine developers, ocean energy demonstration sites, research organisations, as well local and regional authorities.
UK partners:
- Offshore Renewable Energy Catapult (Lead Partner)
- SIMEC Atlantis (in a joint venture with French regional agency AD Normandie)
- Orbital Marine Power
- Minesto AB
- QED Naval
- Cambrian Offshore South West
- Universities of Exeter, Manchester, Plymouth
- European Marine Energy Centre (EMEC)
French partners:
- Sabella (in a joint venture with French regional development agency Morbihan Energie)
- EDF Hydro
- SEENEOH
- Hydroquest
- Bretagne Development Innovation
- Universities of Le Havre, Bretagne South, Caen Normandie
Great untapped potential – now need 10 000 hrs or so of regular operation to gain valuable experience supplying the grid.
At last! UK tidal is well overdue for some attention (and funding!)
Tidal power is one of the obvious renewable energy, and finding the most efficient and cost effective form to demonstrate it must be found as quickly as possible. It is interesting to see how governments can come up with billions, and even trillions of dollars as a result of measures to combat the Corona pandemic, yet have been very slow to assist new technologies trying to develop renewable energies which would provide low cost electric power.
Look at all those Scottish sea lochs, just waiting for tidal power installations. Seems like there is massive potential for clean power to me in this technology. I guess it has its challenges, though!
It’s an interesting dichotomy – installations want to be where tidal flow is strongest but installation and maintenance is most difficult in those areas.
Some sort of specialised support vessel is going to be essential to making sea-bed models viable.
Another in a long line of ‘techno-push’ schemes lobbying for government funds. The ‘Defence’ industry showed the way, followed by the ‘Arts’ industry, and the Great British Public is now wising up and is asking awkward questions.
So, stand by for energy subsidies to be dropped as a result of Corvid, as people’s homes become places of work, and the subsidies now make up 40% of domestic electricity bills!
IF these .alt generation schemes are to be economically worthwhile rather than subsidy-farms, either they have to find a market for their intermittent products, or they have to co-invest in storage to produce dependable products.
In summary, the government should subsidise storage schemes, and NOT generating schemes.
@ TonyN:
The seeds of degeneration were sown with the privatisation of the CEGB. Splitting up the power industry into specialised (pseudo market) sectors is economic theory gone berserk. Any ‘market pull’ policy (FiTs, RoCs and CfDs!) is determined by neoliberal politicians and their ignorant consultants. The only intelligent structure for a natural monopoly is vertical integration.
Yes, the elephant in the room is energy storage. Without it, we’ll never be able to install functional RE capacity to generate electricity, flexibly and sustainably, at low cost (La Rance?). How did the government incentivise an energy storage ‘market’? There isn’t one! Instead, they ‘invented’ a dysfunctional Capacity Market, which gave money to FF generators.
Market-rigging governance is the worst of all worlds. (Historically, the CAP! Currently, Hinkley Point C.) Investment can only be informed by the science if policy-makers have an understanding of the problem! R&I is the knowledge-seeding essential, but ideology set up a money-making monopoly – National Grid – that re-invests absolutely nothing in energy storage research, simply because an ill-conceived Act of Parliament relieved them of any responsibility! Directors and managers are proud of their risk-aversion – that’s how they enrich themselves and their shareholders.
Any designs with little or no ‘commercial’ viability are dead in the water, if politicians claim that the state has no business getting involved in the provision of vital infrastructure – energy and water supply, health services, flood defences, rail/road bridges/tunnels etc. In the specific case of marine renewables, CO-location of wind, wave and TIDAL with Before-Generator Energy Storage (i.e. No HV technology at sea. All installations pump water ashore.) is THE essential design premise. Anything else creates an inefficient and expensive legacy of intermittent, variable OVER-capacity. (compounded by inflexible nuclear power!)
By definition, disruptive innovation has no ‘market’ to incentivise investment. Worse than that, the incumbent industries will fight tooth and nail to stop any novel, competitive products getting help from government agencies. That’s the inevitable effect of neoliberal ‘state-aid’ rules, when wrongly applied (technology neutral) to industrial research. Winners can only be picked from an objective, scientific proof-of-concept programme, divorced from business vested interests. Electricity storage is a false premise. We should concentrate on energy storage, to the exclusion of ‘other’ options.
“If a British Arpa could reduce the cost of carbon capture by two or three orders of magnitude, the impact on the climate crisis would be radical.” What a dumb comment! The vested interests are counting on the continued use of FF! You decarbonise industry by FIRST decarbonising electricity to produce green hydrogen – then CCS is superfluous and a waste of money.
Technology push is the only way to fuel progress and prosperity, but risk-averse oligopolies will always conspire to extract a ‘good’ profit and plough next to nothing back into real R&I.
Recommendation 4.6 – p61 of The Lambert Review. 2003:-
https://www.ncub.co.uk/index.php?option=com_docman&view=download&alias=81-lambert-review&category_slug=publications&Itemid=2728
4.55 Private investment is difficult to attract into proof of concept funding, precisely because the potential of the technology cannot be known before this preliminary work has been done.
Spot on TonyN. -Pumped-storage could be available from a Bristol Channel Barrage in North Devon/West Somerset around Minehead to Wales.
Suggest two tidal lagoons to start with terminating in Caissons holding somre of the turbines and protecting against ship damage with another one between so sliding vertical gates could control tidal surge such as inundated Gloucestership some years ago [“£2 billion insured losses, £2 billion uninsured”]
if a way of preventing sea level rise cannot be found, then eventually the lagoons would be infilled and the barrage brought up to 80 metres. So Caissons could be built to 80 m at the start. Sliding gates – vertically into sea bed. Dredged material used for self-stabilising micro-porous bages under new beaches to save on rock armour. Long slow scour-free beaches have amenity value.
etc etc.
Has the time arrived again for the UK to think seriously about Tidal Energy via the Bristol Channel Barrage?
Serious Electricity availability on a regular time frame.
Reduced inner coastal Flooding issues.
Potential for improved Communication with a Bridge Roadway from Somerset to Wales.
Less dangerous and less costly than Nuclear Power investment.
Do we have a modern day Brunel to build this facility for us?
I worry about the effect on the route of the Gulf Stream if tidal flow in and out of the Bristol Channel and up the Irish Sea is made ‘difficult’. The Gulf Stream might easily ‘decide’ to ‘flip’ it’s route to avoid the UK altogether!
“The huge promise of offshore wind is underscored by the development of floating turbines that could be deployed further out at sea. In theory, they could enable offshore wind to meet the entire electricity demand of several key electricity markets several times over, including Europe, the US and Japan.” The theory is wrong, since an over-capacity of variable RE will never meet and match variable demand without game-changing energy storage and integration with (flood defences) tidal range infrastructure.
No marine renewables (wind/wave/tidal) should be deployed without integral energy storage and the only viable engineering premise for that is the elimination of HV equipment at sea. Ofgem said the use of single radial links from wind farms to land – the basis of the UK’s world-leading offshore wind growth so far – won’t be “economical, sensible or acceptable.”
“Wave and Tidal Energy” designs that don’t have both energy storage and wind turbines are a false premise and a waste of time, money and engineering talent. Marine renewables (aside from tidal lagoons/barrages!) should all float and pump water ashore, through Before-Generator Energy Storage, so that the HV plant (hydro generators and electrolysis) is all built on dry land.
https://renews.biz/59508/irish-welsh-marine-energy-opens-demo-call/
https://renews.biz/59382/1m-to-cut-wave-energy-costs/
“deliver technologies that can produce power reliably.” That would be energy storage then?!
Another example of the blind leading the blind. UK industry can do so much better than this:-
https://renews.biz/59505/french-engineers-form-chinese-floating-team/
CIMC Raffles marketing director Fu Qiang said: “Dolfines has developed a light and passive semi-submersible platform for a large spectrum of floating wind applications.” This has no future.
There is no FOW platform, anywhere in the world, that is fit for its purpose. They must use VAWTs, harvest wave power (and any tidal stream), pump water AND store energy – period.
The first/only infrastructure project for this government is the Aberthaw-Minehead Barrage.
This is a nowhere technology. If the goal is to get the cost competitive with nuclear power – still the most expensive source of electric power there is and which has never been commercially competitive with dispatchable renewables (every nuclear power plant built is still receiving government support), why are they even bothering?