|Energy on the crest of a wave
7 May 2004
Quite why a renewable energy company would choose to name its groundbreaking piece of technology after the world's deadliest snake is not clear.
The Pelamis plutarus, to give the yellow-bellied sea snake its proper name, boasts a venom so deadly that medicine has never found an antidote to it.
Yet Ocean Power Delivery (OPD) has developed its Pelamis Wave Energy Converter (WEC) specifically to help preserve future generations of human life.
Designed to harness the vast power of ocean waves for conversion into the electricity that makes the modern world go round, the WEC is an exciting development in the race for renewable energy sources.
Having attracted interest around the globe, this Scottish invention is being tipped as the lead player in this ever more urgent game.
But will Scotland fully exploit this latest in a long line of innovations made here? Or will it be one more Scots invention whose full potential - and profits - are realised elsewhere?
Not so long ago, renewable power was barely clinging to the margins of the electricity-generating portfolio. Today it is taking centre stage.
The energy white paper last year outlined a commitment to reducing carbon dioxide emissions by more than 60 per cent within 50 years.
While few would dispute the merits of this aim, the debate on how to achieve it intensifies by the day.
The wind power industry might seem the obvious candidate to fill the energy gap which would arise if this policy were adhered to. However, some believe it is incapable of producing significant amounts of electricity or reducing emissions.
In addition, wind farms stand accused of blighting the countryside, damaging tourism and posing a hazard to birds and bats.
Spotting wave power’s potential, OPD set up in Leith in 1998 with the aim of developing a way to harness it. Hence the Pelamis plutarus, the invention which industry insiders tip as the most likely winner of the race for the renewable energy crown.
Weighing 700 tonnes, the Pelamis is huge, with a size and shape resembling four train carriages.
The machine is a semi-submerged, articulated structure which consists of cylindrical steel sections linked by hinged joints.
Moored to the ocean floor via a cable at its nose, it swings about according to wave direction. Waves travel down the length of the machine, causing each section to articulate about the hinged joints.
Hydraulic rams at each joint resist this movement, causing them to pump high-pressure fluid to hydraulic motors. These then drive electrical generators.
This power is fed down a cable to a junction on the seabed, connecting it and other machines via a common sub-sea cable to shore.
The Pelamis is not alone in harnessing offshore energy. A number of offshore wind farms are in development around the UK in water less than 10 metres deep. A typical offshore wind project consists of about 30 turbines occupying an area 10km square and producing about 60Mw.
The Pelamis can outstrip that. A wave farm occupying a similar area to a wind farm could provide four to five times as much electricity.
Dr Richard Yemm is the managing director of OPD and the principal creator of the 750kw Pelamis, which is about to undergo trials in Orkney. He says: "Initial wave projects are likely to be smaller in size. For example a 30Mw project would consist of 40 Pelamis machines occupying 1km square and providing electricity for more than 20,000 homes."
The Pelamis already has its fans. Professor Stephen Salter, an expert in renewable energy engineering systems at Edinburgh University, says: "OPD has done an extremely careful set of survival tests, and the crucial thing here is that this machine should survive and produce the electricity that it has been predicted to produce. Of all the wave power devices that have ever been anywhere near the sea I think this is the truest of them all."
So far, the signs are not good. Earlier this month it was announced that OPD has secured a £20 million deal to sell its technology to the Portuguese company Enersis, with the prospect of expanding the deal by a further £80 million. The Portuguese government has awarded Enersis the grid capacity to build a 20Mw wave farm in the Bay of Biscay, and Enersis remains favourite to win 80Mw more from future bids.
The development has sparked fears among supporters of Scottish renewable energy that Scotland may be about to miss out on developing a vital and profitable industry.
Dr Yemm adds: "All of the site development work is now going ahead and we are talking to some Portuguese manufacturers in relation to some components which we may make over there. This really shows that there is an imperative for Scotland and the rest of the UK to get their act together so we can build some here, otherwise the industry will, I’m afraid, end up over there after all the ideas, and money on research and development and lots of DTI grants to prove the technology have been spent in Scotland.
"If no industrial development follows on then it will be a great loss, and that is a fairly stark message for government to listen to."
A factor hampering the industry’s development in Scotland is that UK subsidies for such ventures fall short of those offered in Portugal.
Because wave power is still very much in its early stages of technological development, it requires high subsidies. However it is anticipated that the cost will fall gradually over the next 15 years, eventually making its price competitive with those of conventional energy sources.
Portugal has set a tariff of 20 Euro cents per unit of energy generated (kilowatt hour) from the first 500Mw of wave power, which equates to about 16 pence per unit , approximately five times higher than that available in the UK.
Maf Smith, development manager with Scottish Renewables, says the UK government need look no further than the fate of the wind turbines which now adorn so many hills.
"The Danes saw this and seized upon the wind market with the result that every second turbine sold in the world is made in Denmark.
"We have leading Scottish firms and great expertise, so the resources for the wave and tidal industry are here, but that doesn’t bring the jobs by itself. We need a market framework for the first few projects. The first one of anything is going to be very expensive. But after that costs come down as the scale of the projects increases.
"We need the Executive to give a clear and strong political commitment that marine energy is vital for Scotland and that they are going to put measures in place to make sure the industry is a success here. We also need the UK government to acknowledge that this is will benefit UK plc, not just Scotland, and examine how best they can achieve this.
"Portugal has created the conditions to allow people to come forward and operate and grow in the industry, and that is exactly what we need here."
In the case of OPD’s Pelamis WEC, the clue may be in the name: pelamis plutarus is the most abundant sea snake in the world, with a massive geographic range across the Pacific and Indian Oceans. If the Pelamis WEC can spread like that, Scotland could be in the vanguard of a cash bonanza with the potential to outstrip the wind-energy goldrush sweeping across these shores.