PETER BROWN, EnergyCurrent.com, February 16, 2009
On a Monday morning in May last year, the Atlantic tide set a turbine in motion on the seabed off Orkney, and the energy captured was connected to the national grid. It was, said Jim Mather, Scotland’s Minister for Enterprise, Energy and Tourism, a “massive step forward”.
The amount of electricity generated may have been tiny, but for marine engineers the significance was huge. Their industry had stopped paddling and started to swim.
For small companies trying to get wave or tide devices off the drawing board and into the sea, many problems lie in wait. All turbines, whether they sit on the seabed or float, must withstand that once-in-a-century wave that could be a thousand times more powerful than the average. Conditions vary with the seasons and the seabed. A device that works in a fjord might not function in a firth. Rigorous, long-term testing is therefore vital.
“There are parallels with wind,” says Alan Mortimer, head of renewables policy at Scottish Power. “Many different types of turbine were proposed in the early Eighties. They boiled down to a small number of successful concepts. The same needs to happen with marine devices, but the difference is that they need to be full- size just to be tested.
“To get a reasonable number of prototypes into the water costs millions. What these small companies need is capital support.”
That, however, is hard to find. The Wave and Tidal Energy Support Scheme (Wates), which put GBP13.5 million into promising technologies, is now closed. Last year the Scottish Government offered the 10m Saltire Prize for a commercially viable scheme, but the Institution of Mechanical Engineers (IMechE), in its recent report Marine Energy: More Than Just a Drop in the Ocean?, called on the Government to provide another 40m.
This would go towards schemes to be tested at EMEC, the European Marine Energy Centre, which has two supported sites, with grid access, at Orkney. It was there that an Irish company, OpenHydro, made the grid breakthrough last year. “It’s desperately important that we grasp the nettle now,” says William Banks, IMechE’s president. “We have the micro-systems in place and I’d like to see them developed to the macro stage. However, unless we do that step by step, we’ll be in trouble.”
An estimated 50 teams are working around the world on marine energy. The danger is that Britain, and Scotland in particular, could lose the race, even though, as Alex Salmond, Scotland’s First Minister, says, “Scotland has a marine energy resource which is unrivalled in Europe.”
Scotland has a quarter of Europe’s tidal resources and a tenth of its wave potential.
Around 1,000 people work in Scottish marine energy, but that figure could billow. “You’re talking about an exercise that could transform the marine industry into something equivalent to oil and gas,” says Martin McAdam, whose company, Aquamarine Power, is growing fast.
Among his rivals in Scotland are AWS Ocean Energy, based near Inverness, with Archimedes, a submerged wave machine; Hammerfest UK, which wants to develop three 60MW tidal sites and is working with Scottish Power; Pelamis Wave Power, who are based in Edinburgh; and Scotrenewables, based in Orkney, who are currently developing a floating tidal turbine.
Politicians need to be educated about marine energy’s potential, says Banks. Indeed, IMechE has highlighted the need for sustained political leadership if what many see as the biggest problem – that of the grid – is to be solved. Why bring energy onshore if it can’t then reach homes?
“Grids were built to connect large power stations to cities. Now you’re going to have electricity generated all over the countryside. It’s a huge challenge,” says McAdam.
“We have had meetings with Ofgen and the national grid companies and we’re outlining the need to have grids to support at least 3,000MW of energy by 2020. That is definitely possible.” McAdam adds: “A European undersea grid is also being promoted and we’re very supportive of that.”
Such a system would help to overcome a frequent objection to renewables – their fickleness. If waves were strong in Scotland, Finland or France could benefit, and vice versa.
Another challenge is the cost of installation. “At the moment we’re competing with oil and gas for boats,” says McAdam. “We need to move away from using heavy-lift, jack-up vessels.” The answer might be devices that can be floated into position and then weighted down.
The race between suppliers is speeding up. Permission for a 4MW station at Siadar, off Lewis in the Western Isles, has just been granted to Wavegen, based in Inverness, and Npower Renewables. It could power about 1,500 homes, creating 70 jobs.
Among the success stories are the three 140-metre, red tubes developed by Pelamis (named after a sea serpent) which already float off the northern Portuguese coast at Aguadoura. More Pelamis turbines are to be installed at EMEC, along with Aquamarine’s wave device Oyster.
Oyster is basically a giant flap which feeds wave energy onshore to be converted to electricity. It has already been made, at a former oil and gas plant at Nigg, north of Inverness. A high- pressure pipeline was completed in December and a hydro-electric station will be installed this spring. In the summer, Oyster will finally be bolted to piles hammered into the seabed.
Unlike wave energy, tidal power needs a channel between two land masses – and in the roaring Pentland Firth, between Caithness and Orkney, Scotland has what has been called “the Saudi Arabia of marine power”, Europe’s largest tidal resource. To exploit it, a GBP2 million contract to build Aquamarine’s tidal power device, Neptune, was awarded last month. It will be tested at EMEC.
Elsewhere, SeaGen, an “underwater windmill” developed by a Bristol company, has just generated 1.2MW near the mouth of Strangford Lough, Northern Ireland.
But the most controversial of Britain’s tidal energy schemes is, of course, in the Severn Estuary, where a barrage could provide around 5% of Britain’s energy. Environmentalists fear irreparable damage to marshes and mudflats, but the Government is known to prefer the barrage to other, smaller options. The decision it takes next year is sure to be eagerly watched in Scotland.
Somewhat overshadowed by the Severn plan is Wave Hub, a project to build a wave-power station 10 miles off St Ives, on Cornwall’s north coast, using both Pelamis and a sea-bed device developed by ORECon of Plymouth. An application to create a safety area around it has just been submitted, part of the meticulous planning that precedes any marine trial.
“We have to have environmentalists looking at the impact on fisheries, flora and fauna,” says McAdam. “And we have to be completely open with the communities we’re going into. But most people realise that climate change and energy security are real things. We want to minimalise our environmental impact and give the country a means of isolating itself from the volatility of oil and gas.”
In theory, marine energy could generate a fifth of the UK’s electricity needs, but that would require a multitude of stations. Bill Banks believes nuclear power will be needed. “But we also need a variety of renewables,” he says. “Marine will take its place along with bio, hydro and wind energy. It’s available, it’s there at the moment, and if we get our act together I think we can lead Europe. We need a synergy of activity.”