A sea change in harvesting of energy
The footprint in the sea is quite small, so its environmental impact is quite small
OVER THE past few weeks, Martin McAdams has been busy overseeing the completion of the underwater base for Aquamarine Power’s latest creation to harvest the power of the sea in the waters off Orkney, at the northeast tip of the Scottish coast.
“We hope to be putting the machine into operation in the coming weeks – but this depends on the number of gremlins we encounter in the commissioning process,” said McAdams, a veteran of both the ESB and Airtricity.
So far, using technology developed at Queen’s University Belfast, Aquamarine has spent £60 million developing its creations, with the first, the 300KW Oyster I, operating successfully for 6,000 hours over two winters.
The beginning of life for the Oyster 800, producing 800KW, was delayed because “we did not have much opportunity to do a lot of commissioning work because we have had three hurricanes through – the winter has been appallingly bad”.
Wave energy requires patience from its backers. Today, it is three to four times more expensive than offshore wind, which is, in turn, significantly more expensive than fossil fuels and nuclear, even if McAdams argues that the true costs of the last two are hidden.
“We need to perfect the technology that we have got. We believe that we have got a good machine here,” he said in London, during a one-day visit to speak with investors.
“We need to reduce the costs dramatically, but that is not a huge concern for now. “With any new technology the first machines are always going to be dramatically more expensive,” but savings from research and development – “learning by doing” – and economies of scale will come in time, he says.
The Oyster I and an earlier prototype fresh from QUB’s water tanks were built with steel, but the Oyster 800 and its successors will employ glass-reinforced fibres, or reinforced plastics. Instead of weighing 400 tonnes, each will weigh 70 tonnes, or less.
From now on, McAdams says the objective is “not revolution anymore, but evolution”. The Oyster 5000, already being designed, will cost “hopefully between 30 and 50 per cent less” than the model currently being tested, along with being “easier to install and manufacture”.
The principles behind all of them are simple, even if execution is difficult. Each turbine has a flap that moves forwards and back with the incoming and outgoing tides, changing position every 10 seconds on average.
“We don’t make electricity in the water. Oyster pumps high-pressure water and we drive a hydro-electric turbine on land. What we put in the sea is as simple as possible. We use fresh water as the pumping fluid, so even if we had a leak we would be leaking water into the sea, rather than oil.”
Aquamarine’s creations, resting on steel piles driven into the seabed in 15m-deep waters, jut above the waterline. “The footprint in the sea is quite small, so its environmental impact is quite small,” McAdams tells The Irish Times.
Conscious of objections, Aquamarine has spent time explaining itself to Orkney’s locals and those at its other site on the island of Lewes. “The most important thing is to understand the local community, understand the concerns, mitigate them and be sensible about it,” says McAdams.
“We have had very positive feedback in Orkney. We spend as much of the construction money in the local area as possible. Last year, we spent £3 million , everyone from the local photographer to a local civil engineer. We try and give as much to the community as we can.”
On Lewes, Aquamarine plans to have up to four turbines in operation by 2015. In Ireland, it is co-operating with ESB International on the WestWave. “There, we think that should be in a position for a build-out in 2016 – one in Clare, or potentially one in Sligo.”