Bright Future for Scottish Tidal Energy

The local interest organisation is working full time with supporting the tidal energy project.

TEXT and PHOTO Charlotte Boström

Tidal water has existed longer than mankind. Nevertheless it is unexposed for commercial use so far. Now big money is being put into projects to make Scotland world leading in the ancient renewable energy.

Compared to other renewable energy sources tidal power has many advantages. Unlike wind and wave power it is very predictable and it is possible to make exact calculations of how much energy the tidal streams will generate.

Another advantage is that the devices are completely impossible to see above the water surface since they are placed on the seabed. Therefore artefacts do not destroy a beautiful view.

Very Expensive

But there are reasons why tidal energy not has been utilized on a commercial scale yet. It is all about the money – it is not financially profitable. The technology is so far expensive, the devices are huge and the low efficiency has not been interesting for investors.

Fraser McCreadie on Hammerfest Strøm.

Company on the Rise

Hammerfest Strøm is a pioneer in the tidal power business. They are developing the devices in the Scottish sound of Islay. If everything goes according to plan this will become the biggest tidal power station ever to be installed into a national grid.

Hammerfest Strøm installed a tidal turbine into a national grid in Norway last year, which is the only successful experiment for commercial use so far.

Research and Development

“Special to us is that we use a ballast weight on the devices, then they do not have to be drilled down in the seabed and thereby they are easier and cheaper to install.

We also work on getting down the frequency of maintenance work which will lower the costs,” Fraser McCreadie says, managing director on Hammerfest Strøm in Glasgow.

The company now runs experiments with tidal devices in Pentland Firth in the north of Scotland. The devices in the sound of Islay will be much bigger and therefore an important test for Hammerfest Strøm.

The Fight Against the Costs

The biggest obstacle for tidal power on the energy market is the price. It is yet far from competitive with fossil fuels or renewable energy from wind or hydro. The main task for Hammerfest Strøm is how to bring down the costs for the electricity.

The tidal devices will be installed outside Port Askaig on Islay.

The plan is to install the tidal devices outside Port Askaig on Islay.

There is Hope

Fraser McCreadie estimates that the tidal energy price will be on the same level as wind within ten years.

“Scottish Power Renewables and Norwegian Statoil are our biggest investors. But the climate on the energy market is changing, and big companies are showing more interest in becoming shareholders in marine energy,” he says.

This is due to more research and development and the fact that the oil price will rise since the global oil resources are running dry. That, combined with the predictability of tidal streams can bring the price down in the future.

Tidal Energy in Scotland
> Scotland has approximately 25 percent of the tidal energy resources in Europe according to a report from the Scottish government.
> According to the advisory organisation Carbon Trust tidal water can produce up to ten percent of the UK electricity demand.

The Technology

Image: Hammerfest Strøm

> The idea of a tidal energy turbine is very similar to a wind turbine. Every device has a capacity to generate 1 MW during peak flow and no electricity during slack water, which corresponds to the electricity consumption of 500 UK households per year.
> In the sound of Islay they will be put on the seabed 50 meters under the surface. The total height from the base to the top of the blade is about 30 meters. According to the Maritime and Coastguard Agency (MCA) this will not affect the boat and ferry traffic in the area.
> The tidal turbines have to be taken up for maintenance approximately every five years. This is a costly and complicated process and the goal is to extend the need of maintenance to ten years.

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