In 2005 The Manufacturer reported that wave and tidal energy generation might contribute to the energy needs of manufacturers within three years. At the beginning of 2010, the UK had the capacity for the generation of a whopping 0.85MW of wave energy and 1.55MW of tidal stream energy. Tim Brown finds despite the current low output, the sea offers very real promise.
Considering that 2.4MW is only just enough energy to power about 1,500 homes, the take-up of this technology has clearly not yet reached its desired potential. But what is the realistic potential for wave and tidal electricity generation, and is it likely to offer a real alternative to other sources of renewable energy? Despite what would appear to be a slow start, the UK is still leading the world, with the largest installed generating base, a further 27MW having received planning consent and 77.5MW of additional projects in various stages of planning. It must be remembered that wave and tidal energy is a developing industry and, as with any new technology, careful development is key to ensure success.
According to government and RenewableUK, the sector’s leading trade association, the capacity for wave and tidal energy is increasing. Over the next decade the industry is predicted to increase its capacity 100 fold to produce up to 2GW of power by 2020.
The UK has a significant tidal range resource, with the world’s second highest tidal range site located in the Severn Estuary — with a benchmark energy output of 17TWh/yr from a Cardiff-Weston barrage. The other highest resource sites in the UK include the Mersey (1.4TWh/yr), Duddon (0.212TWh/yr), Wyre (0.131 TWh/yr) and Conwy (0.06TWh/yr). Through these — and other — tidal range projects there is an opportunity to potentially provide up to 13% of the UK’s electricity generation from tidal range alone. Despite the potential of these areas, planning arrangements have failed to materialise, with environmental concerns commonly cited as responsible for slowing progress.
On 16 March, however, details of the Pentland Firth and Orkney Waters Strategic Area leasing round were released. The Crown Estate awarded an unprecedented 1.2GW of wave and tidal energy project leases, consisting of six wave energy projects totalling 600MW and four tidal projects amounting to 600MW. The sites were awarded to a number of utilities and advanced technology developers, including Marine Current Turbines (MCT), Pelamis Wave Power, and SSE Renewables Developments — joining forces with Aquamarine and Open Hydro, Scottish Power Renewables and E.ON.
According to Oliver Wragg, RenewableUK Wave and Tidal development manager, the announcement is both welcome and exciting news for the industry.
“The leasing round has exceeded all expectations by awarding 1.2 gigawatts (GW) of project leases, considerably up from the originally scheduled 700 megawatts (MW). This clearly demonstrates that the industry has now reached a stage where it is ready to deliver,” he says.
MCT has secured approval to deploy its award-winning SeaGen tidal current technology off Brough Ness, on the southernmost tip of the Orkney Islands (South Ronaldsay) and north east of John O’Groats. The company plans to have its first phase of SeaGen tidal turbines deployed during 2017, with the whole scheme operational by 2020.
MCT is planning to install 66 SeaGen tidal turbines, each capable of producing 1.5MW, in three phases over a four year period in a site area of 4.3 square kilometres. The Brough Ness tidal array will have a total generating capacity of 99MW: enough power for nearly 100,000 homes.
“The Pentland Firth and Orkney waters are strategically the most important marine energy areas in Western Europe, so we are delighted to have secured approval for a lease by The Crown Estate,” says Martin Wright, managing director of MCT. “I believe that MCT is in a very strong position to capitalise on this significant and challenging opportunity. MCT already has the valuable experience of deploying and operating SeaGen in Northern Ireland’s Strangford Lough, and within the next two to three years we expect to have deployed our first tidal farm in UK waters.” SeaGen is the world leading prototype tidal energy turbine designed and deployed by MCT. It is the largest grid-connected marine renewable energy system in the world, last month exceeding 1000 hours of commercial operation in Northern Ireland’s Strangford Lough. It is the first tidal current energy system in the world to have achieved this milestone. The 1.2MW tidal current turbine, which was deployed in April 2008, has achieved a capacity factor of 66%, and so far delivered more than 800MWh of electricity into the National Grid.
Of course, in order to achieve the transition from research and development to full scale implementation, a significant amount of funding will still be required. Over the last decade the Government has invested around £60m in wave and tidal research and development. RenewableUK has produced a document titled ‘The Next Steps for Marine Energy’ which recommends that the government commits a minimum of £220m in capital support for technology development over the next five years, with the aim of powering 1.4m homes (2Gw) with marine energy by 2020, and producing an annual sector turnover of £900m by 2030.
“There needs to be a greater awareness on the initial investment needs of this industry,” says Peter Madigan, the RenewableUK’s head of offshore renewables. “The Danish government spent £1.3bn to establish onshore wind, which currently brings £2.7bn per year in revenue. A properly capitalised wave and tidal sector could create 43,500 direct jobs and generate a potential £4.2bn per year in revenue for the UK economy.” According to the government’s marine action plan, the UK has a unique opportunity to capture the benefits of this new sector through the entire supply chain; from research and development through to engineering, manufacturing, installation, operation and maintenance. ‘This builds on our maritime tradition, most recently expressed over the past 40 years in oil and gas exploration and currently with offshore wind developments. The development of marine technologies will lead not only to a substantial marine energy generation industry in the UK, but more importantly to a substantial supply chain,’ says the report.
If the UK’s technological lead is maintained, a large part of that supply chain will be based in the UK — resulting in an attractive environment for domestic or inward investment in manufacturing facilities. Development of the domestic facilities will also provide significant opportunity for exports of both technology and knowledge. With regards to employment, in the longer term the potential for jobs arising from the wave industry alone will continue to increase, peaking at 16,000 in the 2040s with about 25% of them supporting UK exports.
Players and plans:
Aquamarine Power and SSE Renewables
• 2013 – Implementation of a 200MW wave farm at Brough Head
Marine Current Turbines
• 2017 – First stage implementation of 66 SeaGen tidal current technology turbines
• 2020 – Completion of SeaGen project with a power generation capacity of 99MW
Pelamis Wave Power
• 2011-2020 – Two separate 50MW offshore wave projects off the west coast of the Orkney Islands. One in collaboration with Scottish Power Renewables and the other with e.ON UK.
• 2011-2020 – A 50MW wave farm site off the north coast of Sutherland being developed by PWP.
