UK EYES WAVES AND TIDES

Wave and tidal power -which will win?
Dave Elliott, December 19, 2009 (Environmental Research Web)

"Wave power and tidal current turbine technology, if successfully developed, could supply the UK with about 20% the electricity it needs and possibly much more. The…USA could generate 10% of its electricity from wave and tidal schemes.

"Wave power was the initial leader- the UK launched a R&D programme in the 1970…[but] lost a couple of decades following the withdrawl of government funding for most of the work in 1982 and for the remainder in 1994. Work on Tidal power was also halted…Now however, all three options, wave, tidal current turbines and tidal barrages, are back on the agenda, with the UK still being in the lead, just."

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"Tidal current turbines seem to have the edge in many ways. [W]ith wave energy you are trying to extract energy from a chaotic interface…[W]ith tidal flows, a few metres under the sources, you have nice laminar flow and a more stable environment…[T]here are reputedly 150 or so tidal projects at various scales under tests around the UK…[S]ome full-scale systems are now in place - notably the 1.2 MW Seagen tidal turbine in Strangford Loch, Northern Ireland…A 10MW tidal farm is now planned off Anglesey…[M]any others [such as Open Hydro, Pulse Tidal, Lunar Energy, Proteus, Triton, Cygnet devices] are in line… at the European Marine Energy Centre Tidal Test Site (EMEC) in Orkney…There are many more projects emerging elsewhere in the world…

"But wave energy is not out of the race. The leader is the UK developed Pelamis wave snake system- a 2.2MW version of which was installed in Portugal [but met minor hitches]…[N]ew ideas for wave energy are emerging [from companies such as Orecon, Aquamarine and Tidal Energy Ltd and Green Ocean Energy has] a new wave unit designed to be attached to an offshore wind turbine tower…Progress is also being made on the novel Danish Waveplane concept…"

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"Even so it’s certainly not always straight forward to develop new ideas. For example, the UK’s Trident Energy has been deploying its novel linear motor based wave device for testing off the Suffolk coast at Southwold, but its 20kW demonstration device sank when being taken out to sea…[T]here is still inevitably a major focus on large tidal barrages, if nothing else because of their scale -like 11mile long 8.6GW barrage proposed for the Severn estuary…[and] barrages elsewhere in the UK, including the Mersey, Solway Firth, the Wash and the Humber.

"[T]he potential elsewhere is also large- especially for tidal…South Korea’s theoretical tidal resource [is] 1000 GW, and they have some ambitious projects underway or planned, including nearly 2GW of tidal range projects and 100MW of tidal current turbines…[Wave] projects [are] underway around the world, including a range of tethered buoy systems, and in the UK work is in now underway on the £42m Wave Hub project 10 miles off the coast of North Cornwall. The seabed ‘socket’ can take up to four devices at any one time for field testing…That could speed up the development wave power."