The Orkney Isles are a fascinating place: Europe’s best preserved Neolithic village, home of “the best whisky in the world”[i], and host to “the world’s first and only accredited wave and tidal test centre for marine renewable energy“[ii]. The European Marine Energy Centre (EMEC), is found in Stromness, and, unbeknown to most mainland Brits, is playing a major role in helping Scotland lead the international race to harness the power of the sea.
The town of Stromness, home to the European Marine Energy Centre.
Following a 2001 recommendation by the House of Commons Science and Technology Committee, EMEC was set up by a group of public sector organisations in 2003. Its main goal was, and is, to accelerate the development of marine energy converters in the UK, by providing grid-connected test sites and support services. Today EMEC has 14 test berths, spread across two areas, as well as two further “nursery” sites for testing scaled-down prototype devices. In 2012 EMEC became financially self-supporting, a true vindication of its existence. Developers from all over the planet are using EMEC’s services, and all 14 of its test sites are occupied. EMEC has six wave energy test sites in the waters off Billia Croo, on Orkney’s West Mainland, and eight tidal energy test sites in an area known as the Fall of Warness, off the Island of Eday.
Ocean Power Delivery’s “Pelamis P2” undergoing trials at EMEC’s Billia Croo test site.
The beauty of these test berths is that developers can avoid the costly and time consuming processes of securing permission from the Crown Estate (who owns the sea-bed around the UK), establishing a grid connection, which can take over a year, and installing subsea cables. Furthermore, EMEC has a huge bank of data going back over a decade, which describes the sea state and allows developers to predict the loads their devices will be subject to; EMEC has expertise in delivering and recovering devices to their berths; they can assist with design issues, and in general they can share their vast experience gained through having witnessed and assisted numerous developers in going through the process of deploying new marine energy converters.
Without EMEC, the rate of development would undoubtedly be significantly slower. EMEC’s current clients include the following:
Wave Energy Developers
1. Established in 2005 and based in Edinburgh, Aquamarine Power’s “Oyster” consists of a giant arm attached to the sea-bed; the device swings back and forth in the waves, and pumps high pressure water through a shore based hydroelectric turbine.
Aquamarine Power’s “Oyster” wave energy converted being installed at Billia Croo, Orkney.
The first 800kW mark-II Oyster was grid-connected at Billia Croo in June 2012, and after successful trials Aquamarine Power is currently working with Scottish and Southern Energy to develop a 40MW wave farm off the Island of Lewis, and a further 200MW wave farm in Orcadian waters; a hugely positive development to come out of EMEC (although some stakeholders do object to such large scale occupation of the sea-bed).
2. E-On, a multinational utility provider, purchased a Pelamis “P2” wave energy converter in 2009, marking the first significant investment in wave power by a major company. The Pelamis device was developed, and is being perfected, by Ocean Power Delivery, also based in Edinburgh. It is the brainchild of Richard Yemm, a former student of Professor Stephen Salter – the godfather of wave power – famous for inventing Salter’s Duck in the 70’s. The Pelamis wave converter consists of five sections which shift and rotate in the waves. Each movement forces high pressure fluid through a turbine housed within the device, which in turn spins a generator. The device is almost 200m long and weighs approximately 1,350 tonnes[iii]. E.On has secured permission from the Crown Estate to develop a 50MW Pelamis P2 wave farm to the North of Stromness, which would incorporate up to 66 devices.
3. Scottish Power also installed a Pelamis P2 in spring 2012, and this device is now operated alongside E.On’s P2. In a rare collaboration between rival energy providers, Scottish Power and E.On have agreed to share the learning and experience gained throughout their sea trials. Scottish Power has also secured permission to install a 50MW wave farm in the waters off Marwick Head, Orkney.
4. Seatricity is a relatively recent British entry into the wave power industry. Their device incorporates several floats, rising and falling with the waves. Each float operates a pump which forces seawater through a shore based hydroelectric turbine. By using several floats and pumps, each shore based turbine can generate a peak output of 1 megawatt. Having completed successful trials in the calmer waters off Antigua, Seatricity had planned to install their first device at Billia Croo during 2012. This has been delayed by various manufacturing issues, but 2013 should see their device up and running.
Seatricity’s wave energy converter harnesses the sea’s energy via the waves’ interaction with numerous floats, each connected to a pump on the seabed.
5. Vattenfall, Europe’s sixth largest producer of electricity, has recently secured the rights to one of EMEC’s test berths, and they too will be testing the Pelamis P2 come 2014. With a refined version of the device under development, Vattenfall will benefit from the testing currently being carried out by E.On and Scottish Power. If the EMEC seatrials go well, Vattenfall has plans to develop a 10MW wave farm off the coast of Shetland.
6. WELLO OY is a Finnish company that has been developing wave power devices since 1976, making them one of the elder statesmen of the industry. In 2008 they settled on the “Penguin” model, and have now developed a 500kW prototype. The Penguin is unique in that it utilises a flywheel; a highly efficient method of accumulating and temporarily storing kinetic energy. The asymmetric hull heaves and rolls in the waves, with each movement accelerating a heavy weight mounted on an internal axle. The same axel turns a generator, with the electricity being exported via a subsea cable.
Cut away diagram of Wello Oy’s “penguin”; the red weight rotates and drives a flywheel and generator as the device pitches in the waves.
In January 2013 the device was returned to Riga, Latvia, for upgrades and maintenance, and is expected to return to EMEC in May 2013. With no moving parts exposed to the elements, this device may have distinct advantages over the likes of the Pelamis and Oyster.
Tidal Energy Developers
1. Norwegian company Andritz Hydro Hammerfest is a global equipment supplier to the hydroelectricity industry. In December 2011 they successfully deployed their 1 megawatt tidal turbine at EMEC’s Fall of Warness site. Their device is a sea-bed mounted 3-bladed turbine, which works in the same way as a wind turbine. The designers opted for rugged simplicity over maximum efficiency, with a fixed turbine orientation: This means the turbine must be installed in the correct alignment for the local tides, and that any variation in the tide’s direction of flow will lead to a reduced output. Thankfully, most sites have a consistent orientation of flow; 180o shifts between the ebb and the flow simply drive the turbine in the opposite direction.
2. Founded in Australia, but now with head offices in London and Singapore, Atlantis Resources claim to be “the leader in marine power” (debatable!), and began testing their tidal turbine in Australia as far back as 2002. After further tests in Singapore, including tow-tests, the Atlantis AR1000 turbine is now undergoing trials at the Fall of Warness, with the Orkney tides providing the toughest test to date. The turbine sits on a 1,300 tonne gravity base, and stands 22.5 metres tall.
Atlantis Resources’ “AR1000” tidal turbine being prepared for installation.
Atlantis has secured a deal to supply turbines to the Meygen Project; a joint venture between Morgan Stanley and International Power, which ultimately aims to install a 398 megawatt wave farm in the Pentland Firth, just South of Orkney. This is a hugely ambitious project, and the infrastructure required in the North of Scotland – harbours, supply vessels, staff, offices – would have a significant effect on the local economy, but also perhaps on the environment.
3. Dutch company Bluewater Energy Services specialises in offshore storage systems, but has now branched out into tidal energy. Bluewater manufactures a floating support structure for tidal turbines. Their device works with a range of turbines, and can boost their performance by positioning them closer to the surface where the energy density is higher. Testing in Orkney is in conjunction with Italian turbine manufacturer Ponte di Archimede.
4. When they’re not busy making motorbikes, Kawasaki have found the time to develop a pretty respectable 1 megawatt tidal turbine. Their solid, yet orthodox, sea-bed mounted device will be tested at EMEC in 2013/14, with component testing presently being carried out in Holland. Kawasaki are using a number of UK companies to assist in the design and manufacture of their device, and are considering our shores for the assembly and fabrication of the finished article.
5. Dublin-based OpenHydro was the first developer to use the tidal test site at the Fall of Warness.
The strength of Orkney’s tides is clearly visible as the sea rushes past OpenHydro’s test turbine, raised for maintenance, at the Fall of Warness.
Their unconventional, open-centred turbine was installed in 2006, and was the first tidal turbine to be grid connected in Scotland. Uniquely, their turbine is mounted on steel piles and can be raised out of the water to facilitate maintenance or for protection from heavy seas.
6. Founded in 2002 by a former student of the International Centre for Island technology in Stromness, ScotRenewables Tidal Power Ltd has successfully developed and are testing a 250kW prototype tidal turbine. Their device is different to other turbines in that as opposed to being sea-bed mounted, the machine consists of two turbines attached to a floating structure. This feature, combined with the turbines’ ability to retract into a horizontal position for towing, allows for easier maintenance and repair; the device can be towed back to port quickly and easily, avoiding the need for expensive on-site maintenance (subsea work involving divers is exceptionally expensive). Additionally, the device is mounted on a universal ball-and-socket style mooring which allows it to swing into whichever direction the tide flows. ScotRenewables are currently designing a two megawatt turbine, which is on course to be the most powerful turbine ever produced.
7. Bristol-based Tidal Generation Ltd was established in 2005, but became a subsidiary of Rolls-Royce in 2009, and is soon to be passed on to Alstom, a multinational company specialising in the transport of energy. TGL installed a 500kW prototype turbine at the Fall of Warness in 2010, and are currently working on a 1 megawatt device. Their machines are mounted on a tripod which is secured to the seabed by drilling and piling. Importantly, the nacelle (main body of the turbine) rotates on the tripod to meet the oncoming tide, and is buoyant, which allows it to be towed to and from the site for installation or maintenance.
8. Finally, Voith Hydro is a subsidiary of the Voith Group, a German company which manufactures around a third of all hydroelectric turbines and generators. In a joint venture with international electricity supplier RWE Group, Voith will be installing their first 1 megawatt tidal turbine at the Fall of Warness in 2013.
As you can see, EMEC’s clients are a fairly international bunch. This is great news for Scotland and the UK. EMEC is helping to establish a reputation for marine energy expertise, which should be self-propagating; as more investors come to Scotland, the local knowledge pool will grow, as will our reputation. Scotland already has a greater number of wave and tidal energy devices being developed and tested than anywhere else in the world. Supportive businesses such as the presence of dynamic positioning vessels (for installing moorings and cables), harbour facilities, fabrication yards and staff training facilities, which couldn’t find enough business elsewhere, should thrive in the North of Scotland.
As Neil Kermode, EMEC’s managing director put it: “If you go to any oil town in the world, there’ll be somebody from Aberdeen there, doing business, making money and bringing wealth back to Scotland. In the future I believe you’ll go to marine towns […]and there’ll be a link back to Orkney. People will know where it is on the map, will know people who’ve been here and they’ll have an affinity with us.” Neil’s claim is evidenced by various international agreements; EMEC recently signed a memorandum of understanding with Incheon Metropolitan City in South Korea, to provide technical assistance with the design, construction and operation of a tidal energy testing facility. Similar agreements are already in place with the Ocean University, China, the Ocean Energy Association of Japan, the Pacific Marine Energy Centre in Oregon, and Canada’s Fundy Ocean Research Centre for Energy. That’s pretty impressive global coverage for a town of just over 2000 people!
Kermode goes on to say that EMEC’s international clients “recognise we are the experts. We’ve been treated with great courtesy and respect in all these overseas locations and they genuinely value what’s going on in Orkney. They welcome the fact that we come in and say we’re willing to help and would like to build a long-term relationship. I think that’s really helped the reach of Scotland plc into these countries as we’re seen as bringing a quality offering.” So long as we don’t indulge in any laurel-resting, Scotland stands to make both a healthy profit and a healthier still contribution to reducing global carbon emissions. The World Energy Council has estimated that the Earth’s oceans have the potential to generate approximately twice our current electricity demand, or about two million megawatts[iv].
The beauty of tidal power is that it can be accurately predicted months in advance, unlike wind energy. This means its contribution to national grids is far more useful, and tidal energy farms in different parts of the country, subject to different tidal states, can be used to provide a smooth power curve. Wave energy sits somewhere between wind and tidal power, with sea states being highly forecast-able, but not predictable. As a tip-of-the-hat to realism, however, let’s take the UK as an example: In 2011 the UK generated 368 terawatt-hours, or 368 million megawatt-hours[v]. Just for the sake of argument, let’s assume we are going to generate all of this energy from tidal power (and we’ll ignore the storage and peak load issues): With 8760 hours in a year, that’s 42,000 one megawatt tidal energy converters working flat out. But tidal energy converters have a typical load factor of 27%[vi] (wind turbines vary from around 25-45%, depending on their location), so it turns out we would need over 155,000 devices in our seas. Let’s be optimistic and say that development at EMEC and elsewhere quickly leads to an industry standard of 3 megawatt devices. That would reduce the requirement to 52,000 devices.
Sounds like a lot? It is – there are currently less than 3000 large wind turbines in the UK[vii]. So while the seas may have the potential to meet our electricity requirements, the practicalities of achieving this are more than a little uncertain. That said, there are genuine plans and preparations being made for the installation of 1,600 megawatts of marine energy capacity in Orkney waters by 2020. With a 27% load factor, these would generate 3.8 terawatt-hours of green electricity each year; 1% of our national demand from a trail-blazing project in one small corner of the country, and enough to supply electricity to almost half a million homes.
Artist’s impression of a Pelamis wave farm.
Marine energy is still at an early stage, with the current situation being likened to wind power twenty years ago; many different devices are being developed and tested, with no clear winners yet. When the best designs and materials become clear, several things will happen; one or two designers will make a lot of money, economies of scale will evolve in the manufacturing of components, and governments around the world will (hopefully) provide enticing incentives for the now-proven technology. The potential is there to generate a huge amount of energy from the oceans, with certain pros and cons over wind power, (e.g. predictability and cost respectively), but the practicalities and level of objections from other sea-users will pose significant problems. In the meantime, a small group of islands off the north of Scotland continues to punch well above its weight in terms of international significance, and we can all watch in wonder as they help to lead the world towards a cleaner, more sustainable future.