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Islay reaps its tidal power

By Ian Fraser

Published: The Sunday Times

Date:  August 22nd, 2010

The Hebridean island has teamed up with energy giant Scottish Power to tap a reliable source of electricity with underwater turbines

When the MV Eilean Dhiura ferry crosses the Sound of Islay, passengers often think she is heading in the wrong direction. The small roll-on, roll-off vessel has to contend with a fierce tidal current as it makes the journey from Port Askaig, on Islay, to Feolin on the neighbouring island of Jura.

“It is such a fast-flowing piece of water, the ferry has to crab its way across,” said Andrew Macdonald, tidal energy project officer at Islay Energy Trust.

Macdonald has spent years trying to find a way to harness that natural energy, and now Islay Energy Trust has teamed up with Scottish Power to generate tidal power from the sound.

A planning application was lodged last month for a 10-strong array of 1MW underwater turbines, which will generate the power for Islay’s 3,500 residents and all its whisky distilleries, for 23 hours a day. “A lot of hot air has been talked about tidal energy but this project is something tangible that is already bringing real money and real jobs to Islay,” said Macdonald.

“This is the very start of the marine renewables industry, and I’m sure Islay will be able to capitalise on that. Experience gained here will almost certainly bring opportunities elsewhere.”

When the Islay Energy Trust sent a robotic submarine (ROV) into the Sound of Islay in July 2008, it thought it had the waters to itself. The trust had examined various renewable energy sources, including wind power and biomass, but had been unable to find ways to make them work, and so decided to have a serious look at tidal power.

“Within a month Scottish Power was doing the same,” said Macdonald. “We are a small organisation with a voluntary board of eight people. Scottish Power is Britain’s largest renewable energy producer. It was always going to win. So we said, how about working together?”

Scottish Power Renewables, a subsidiary of Iberdrola, the Spanish energy giant, was already heavily involved in the European Marine Energy Centre (Emec) test site off the coast of Orkney. But Keith Anderson, the director of renewables, said the power company wanted to keep its geographic options open.

Scottish Power had examined a number of sites round the coast but was leaning towards Islay. The ROV survey confirmed that the narrow straits had near-perfect conditions. A tidal stream flowing at three metres per second was complemented by a predictable, linear flow. Also, the sound, which runs north-south, is sheltered from high winds and waves.

Scottish Power Renewables and Islay Energy Trust struck a working agreement, with the trust acting as subcontractor to provide local services, including community liaison.

Scottish Power will install the tidal turbines, made by the Norwegian company Hammerfest Strom, in 2012 in a trench running for about 1.5km south from Port Askaig. They are expected to be operational by the following year.

Alex Salmond, the first minister, has often said that Scotland has the potential to be the “Saudi Arabia of marine renewables”. Critics have questioned whether this can become reality.

Obstacles include the need to fund an offshore electricity grid, estimated at up to £10 billion, and whether generous subsidies for renewable power will continue in the climate of austerity.

Tidal power enjoys more generous government subsidies than other forms of renewable energy. Under the renewables obligation scheme, which encourages electricity suppliers to switch from traditional sources, an onshore wind farm receives one Renewables Obligation Certificate per megawatt, while offshore wind farms receive two and tidal projects get three.

The Hammerfest Strom turbines, which resemble stockier versions of wind turbines, will rise 30m from the sea bed. The three blades rotate slowly — 10 times per minute — to minimise danger to sea life.

Hammerfest installed a 300kW prototype off the Norwegian coast in 2003, the first in the world to be connected to a national grid. This has generated electricity with minimal maintenance ever since, giving Scottish Power sufficient confidence to commission last week the first 1MW version for a trial at Emec.

Keith Anderson concedes, however, that some doubts remain over the commercial viability of tidal power. “The aim of the Islay array project is to demonstrate how these machines work together, how they interact on the sea bed, and how they link into the grid,” he said.

“You won’t get to the true commercial reality of tidal power until you get to the next step, which is our project for the Ness of Duncansby.” That 95MW project will see several arrays of up to 20 turbines each embedded in the floor of the Pentland Firth from 2015. Anderson added: “Once you have got to that level, you can make more realistic cost comparisons with other forms of generation.”

Fishermen were initially opposed to the £50m proposal for the Sound of Islay. However, the site of the array will be limited to a narrow stretch of water, where the sea is too deep to fish for crabs. Macdonald added that the trust was discussing possible mitigation with lobster fishermen, including seeding young lobsters elsewhere.

Diageo, the drinks group, has already signed a deal with Scottish Power to take the Islay electricity to four of its distilleries. It believes tidal power is likely to be “more resilient” than existing supplies, which can be disrupted by storms.

  • This article was published in the  energy and environment pages of The Sunday Times business section on August 22nd, 2010. To view it on The Sunday Times website, click here (may require subscription).

Short URL: http://www.ianfraser.org/?p=1699

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1 Comment for “Islay reaps its tidal power”

  1. nice story Ian

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