Tidal turbine powers up in Orkney

AK-1000 tidal energy turbine before it is shipped to the European Marine Energy Centre test site in the Orkney Islands
AK-1000 tidal energy turbine before it is shipped to the European Marine Energy Centre test site in the Orkney Islands Photo: Reuters/David Moir

A tidal turbine being tested for use in the world’s first tidal turbine array in Islay on the West coast of Scotland has proved a success in hostile waters off the North of Orkney. Scottish Power Renewables fitted their HS1000 turbine at the end of last year and it has already been hooked up to the grid and is powering the Orkney Island of Eday.

The 1MW machine is weighed down on the seabed 50 metres below the surface of a stretch of water called the Fall of Warness. It has some of the strongest tides in the world with an Atlantic swell colliding with the North Sea. Tides in the area can reach up to 8 knots in Spring tides.

Keith Anderson CEO of Scottish Power Renewables said:

The performance of the HS1000 has given us great confidence so far.

We have already greatly developed our understanding of tidal power and this gives us confidence ahead of implementing large scale projects in Islay and the Pentland Firth.

Surveys have shown Islay and the Pentland Firth, on the South coast of Orkney, to have some of the best potential in the world for tidal energy projects. Those same studies indicate that up to 20% of the UK’s energy needs could be met by tidal energy.

At the moment the development of tidal turbines is hugely expensive – around £3m per megawatt built. However the industry is still in its relative infancy and the advances made in Orkney have the potential to make development of the technology more economic and efficient.

The usual criticisms levelled at wave and wind power have not, so far, been attributed to tidal turbines. Sitting 20m below the surface of the water they cannot attract the criticism of being an eyesore and because the blades move so slowly fish and marine mammals can easily pass between them.

Now that the technology has been proven in tough conditions off the coast of Orkney Scottish Power Renewables plans to start development on the ten turbines they plan to install in the Sound of Islay.

That project will be the first of its’ kind in the world and will provide enough energy to supply Islay’s 3500 homes as well as its’ famous whisky distilleries.

Brendan McCarron from Diageo’s Caol Ila distillery told ITV News:

We’ve been using the same processes to make our whisky since the 1800’s but that doesn’t mean we can’t embrace new technologies in order to make ourselves more efficient and more environmentally friendly.

The global drinks giant produces tens of millions of bottles of Scotland’s national drink on the Island every year and each bottle could soon be branded as having being made using green energy – something which would fit with the company’s corporate green strategy.

One of the main benefits of tidal energy is of course its predictability and reliability. It is possible to calculate the exact amount of energy a tidal turbine will be producing at a certain time of the day, every day of the year. The same cannot be said of wave or wind power.

Map of Orkney area
Map of Orkney area Credit: ITV News

For the residents in Islay that reliability cannot come soon enough. The island is currently supplied by the mainland grid and Hunterston Nuclear power station in Ayrshire. This can make their supply intermittent.

Andrew MacDonald of the Islay Energy Trust said: ‘

We are at the end of the main grid and that means we suffer frequent electricity black outs.

When the tidal project is up and running we’ll have our energy source sitting in our own back yard and the supply will be far more consistent.

Tidal turbine installation at Orkney
Tidal turbine installation at Orkney Credit: ITV News

Some concerns had been raised by local lobster fishermen in Islay about the impact of ten tidal turbines in the Sound of Islay. However they are now in support of the project after being assured that the turbines will not affect the channels where they work.

It’s even hoped the bottom of the turbines could in fact provide attractive nesting areas for lobsters and crabs.

With ambitious targets set by the UK and Scottish Governments for renewable energy it seems the race is on to turn the tidal currents around Britain electric.