“ The Scottish government wants Scotland to be the first country to successfully deploy a wave or tidal energy farm”.
COVER STORY
“ The Scottish government wants Scotland to be the first country to successfully deploy a wave or tidal energy farm”.
for Energy Systems is also at the forefront of research into marine power technology.
“ The Scottish government has set world-leading targets for the development of renewable energy, including [ sourcing ] 100 % of Scotland’ s electricity consumption from renewables by 2020”, Anne MacColl, chief executive officer of SDI, told BCCJ ACUMEN.
“ This is driving innovation and entrepreneurship across a number of renewable energy technologies, including wave and tidal energy”, MacColl said.“ The Scottish government wants Scotland to be the first country to successfully deploy a wave or tidal energy farm”.
The Intergovernmental Panel on Climate Change has estimated the world market size for wave energy at 8,000 – 80,000TWh per year. The top end of this estimate is five times the current global energy consumption.
In the UK, the technically and economically recoverable resource has been estimated to be 50 – 90TWh of electricity per year, or 14 – 26 % of current UK demand.
Given that Scotland accounts for 25 % of Europe’ s tidal-energy and 10 % of its waveenergy resources, the potential is vast.
With funding in place, the next step will be to move from research and development to commercialisation of this renewable energy source.
Pelamis was established in 1998, when a support mechanism was set up by the British government to help promote marine renewables.
“ At that point, I recognised that this support could be the opportunity to prove that wave power is more than just a good idea and had the potential to be a commercially viable method of generating electricity”, Richard Yemm, founder of the firm and inventor of the Pelamis design, told ACUMEN.
“ Through the work completed over the past 15 years, we are confident that the Pelamis system is the best and most advanced wave energy technology in development”, Yemm said. His firm is focused on bringing the Pelamis wave energy converter to the commercial marketplace.
“ Right now that means demonstrating the technology, enhancing its performance— while reducing costs to become competitive with other renewable sources of energy— and developing suitable sites at which wave farms could be deployed”.
Yemm’ s device consists of five sections linked by universal joints that permit flexing in two directions. The machine floats, semi-submerged, on the water surface and faces in the direction from which the waves are coming. As waves pass along the length of the machine and the sections bend in the water, the movement is converted into electricity via hydraulic power take-off systems housed inside each joint. The power is then transmitted to shore along subsea cables.
The machine operates in water depths greater than 50m and typically is installed 2 – 10km off the coast. The device is rated
at 750kW and, on average, one machine will provide sufficient power to meet the annual electricity needs of approximately 500 homes.
Pelamis already has set some world records for marine energy including, in 2004, the first export of electricity from an offshore wave energy converter to an inshore grid network. Then, in 2008, it delivered the world’ s first multiple machine wave farm to Portugal. However, Yemm admitted that it has not always been plain sailing.
“ Developing wave power technology is not an easy task and some of the learning processes naturally show you what doesn’ t work, rather than what does”, he said.
“ We’ re over 15 years into the development of Pelamis, including building a total of six full-scale, gridconnected machines. And so, thankfully, we’ re now at a stage of proving and enhancing components and features. Pelamis technology already works; now we need to make it better and cheaper”.
EMEC, established with funding of around £ 30mn, plays a critical part in that research and is capable of simultaneously testing 14 tidal and wave-energy designs.
The centre’ s Billia Croo test site was selected because it has some of the greatest wave-energy potential in Europe, with an average wave height of 2 – 3m. The highest wave recorded there was 17m.
EMEC’ s second main test site is at the Fall of Warness, chosen for its highvelocity marine currents, which can reach 8 knots in the spring tides.
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