Sunday 17 August 2008

Wave power all at sea until tide turns


Richard Wilson

Extract all the wave power you can from the Atlantic coast of Scotland and it would add up to the equivalent of about four nuclear power stations, says David MacKay, professor of natural philosophy in the physics department at Cambridge University. “It’s a very large amount. A ballpark estimate of what is required to get Scotland off fossil fuels is either 10 nuclear reactors, or 10,000 wind turbines.”
In terms of raw power, MacKay estimates that waves approaching Scotland’s coastline represent 30 gigawatts (GW). The tides beneath the surface have even more power — 60GW says MacKay. He calculates that 12.5GW of electrical power could be extracted from tide and wave — almost half of Scotland’s total energy consumption of 26GW.
With the UK government setting a target of 15% for clean energy by 2020 — and the Scottish Nationalist government an ambitious 50% target — the sea can no longer be considered as too challenging in which to work.
So why are we not forging ahead with this technology? The world’s first commercial wave farm has been developed and built by an Edinburgh firm, Pelamis Wave Power. Three of their football-pitch-sized turbines are bobbing about in the Atlantic — but off Portugal, not Scotland.
The government in Lisbon offers enough subsidy to make it commercially viable. The UK government — energy matters are reserved to London — is less encouraging, according to leading scientists.
This is despite the fact that the European Marine Energy Centre, a testing site for wave and tidal power, is based in Orkney. Its presence here, along with the work of our universities, makes Scotland a world leader in research into this vital alternative power source. But we need government help to transform our scientific and technical expertise into a commercial industry.
The UK government set up the Marine Renewables Deployment Fund, with a budget of £42m, to help firms develop projects, but no scheme has yet qualified for a grant. The Scottish government has been more supportive, with all of its £13.5m funding allocated.
Jim Mather, the energy minister, has described marine power as “the heart of our ambitions to develop a vibrant renewables sector”. John Griffiths, a non-executive director of the Orkney centre, is clear where blame lies. “In 1999 everybody was saying that come 2005 we should be moving towards a range of commercial tidal and wave devices. That time has gone and among the things that have held up progress has been a huge emphasis on wind. Some of the inertia has been evident from Westminster compared to the Scottish government. There is a dearth of funding in wave and tidal power.”
Turbines at sea are less controversial than windmills, whose presence has upset many communities. Islanders on Lewis who successfully opposed a giant windfarm have backed a recent application for a wave power station operated by Wavegen, an Inverness-based technology company, and Npower Renewables.
Orkney is to test a number of projects, such as Ocean Power Technology’s PowerBuoy system. Another, OpenHydro’s tidal turbine, was connected to the national grid last May, generating electricity to power up to 100 homes. But progress is slow when financial support is muted.
“The sea is a harsh environment,” says Peter Fraenkel, technical director of Marine Current Turbines, which installed a device in Northern Ireland’s Strangford Lough. Looking like an upside down windmill, the structure has the potential to generate electricity to power 1,140 homes. “The sheer force of fast moving water is horrendous,” says Fraenkel. “It takes modern engineering capabilities to come up with solutions. Marine power subsidies are not as generous as they should be.”
Some say Britain is making the same mistakes as in the early years of wind power. “We don’t have a wind industry because in the early days of wind turbine development it wasn’t taken seriously by government,” says Fraenkel. We did not invest in the technology, allowing Danish and German firms to develop it. Now they are making money across the globe.
Tide and wave power will need government help to become commercially viable. Otherwise they too could be developed abroad, and we will miss the chance of a lucrative industry offering highly skilled engineering and manufacturing jobs.
A man particularly aware of Britain’s neglect of renewables is Professor Stephen Salter, generally regarded as the pioneer of wave power. He invented a device in the 1970s called Salter’s Edinburgh Duck, which could extract 90% of energy from waves. But the UK government withdrew funding from wave power in 1982, many believe because of the influence of the nuclear industry.
“We’ve got a good resource and there was a lot of good engineering in the early days,” says Salter, professor of engineering design at Edinburgh University. “We can make ships, so we should be able to make these.”
Salter wrote an energy review document for the SNP two years ago that suggested previous calculations of the energy potential of the Pentland Firth, the deep body of water that separates the Orkney Islands from Caithness and is renowned for the strength of its tides, were underestimated.
He believes that if turbines can be designed to work on the bottom of the sea bed, 70m down, and be placed close together, up to 20GW of energy could be extracted from the firth.
Yet having spent 35 years in the field, he, too, is dismayed by the lack of drive from Westminster. “Marine power should be getting a different flavour of subsidies because the wind people are now building in such quantity they are getting their price reduction,” he says. “If we just go on the way we are, nobody will do anything except wind. I think there are still people around who don’t want it to work and who want to go to nuclear.”
Britain boasts almost half of Europe’s tidal stream sites — where the underwater currents can be used to drive turbines — and 47% of Eu-rope’s wave resource. Des Browne, secretary of state for Scotland, is robust in his defence of the UK government’s input, arguing that Britain has the “most comprehensive package of support measures for marine energy anywhere in the world.” He says Westminster is determined to commercialise the technology and has committed more than £100m since 2000. This includes the renewables fund that has still to allocate grants to marine projects and the new Energy Technologies Institute, based at Loughborough University.
“Wave and tidal power . . . could be key for sustainable UK electricity generation in the long term, and provide huge commercial opportunities. We want to lead the way, and that’s why we are undertaking a feasibility study on whether to support a barrage or another project to exploit the tidal power of the Severn estuary,” he said.
Griffiths is less convinced. “The government put into research and development for nuclear something like half a billion a year, for about 17 years,” he says. “If they had put 10% of that [into wave and tidal power] every year since 1999, the marine power situation would look different.”