Large turbine would allow fewer machines in plan

A powerful new wind turbine which is set to hit the market could allow Viking Energy to cut 30 machines from its windfarm plan without reducing the amount of electricity it would generate.

Shrinking the 150-turbine grid by 20 per cent could help pacify many opponents of the scheme and others who back the windfarm concept but baulk at its sheer size.

The new turbine being developed by Vestas is anticipated to be rated at 4.5MW, a significant 900 kilo­watts greater than the Siemens 3.6MW machine which Viking Energy had pencilled in as the most suitable for its project.

Viking Energy project officer David Thomson confirmed that if the new model becomes commer­cial­ly available soon it could be factored into the company’s forthcoming review of its windfarm proposal – the so-called addendum to its planning application which will try to address the many concerns raised about the proposed windfarm, particularly regarding the number and size of the turbines.

Mr Thomson said: “Part of the consideration of the review of the overall design includes what are our current turbine parameters. We’ll look at what Vestas come with but it may, or may not, have a bearing on what we actually have. It may present another option which we don’t have today and didn’t have a year and a half ago.” He added: “It still only becomes an option. It doesn’t automatically become the chosen replacement.”

The nature of the changes set to be floated in the addendum remains something of a mystery at this stage, Viking Energy having given itself until the turn of the year to table its compromise proposals. Mr Thomson said even Viking Energy did not have the answers yet as it investigates how to react to the mass of feedback from public and official bodies.

Other factors which could allow Viking to reduce the size of the windfarm include any significant fall in the price of turbines and – crucially – the still-unresolved issue of transmission charges which, if substantially reduced as a result of pressure on the electricity regulator Ofgem and National Grid, would require less power to make a profit, translating into fewer turbines on the hills.

Viking Energy only learnt about the new, more powerful, turbine at a trade show last month and Mr Thomson said Vestas had been “a bit coy” about giving out details of its yet-to-be-launched product. However, it has previously spoken about developing a 4.5MW turbine. News of Viking’s interest in the new machine emerged during the recent windfarm tour in central Scotland, which the company organ­ised for the local media and a small group of councillors, community councillors and representatives of public bodies.

There are even larger turbines already on the market. German company REpower makes 5MW machines, two of which have been used in Scotland on the experimental Beatrice offshore project in the Moray Firth, next to the Beatrice oil platform. REpower is now working on a 6MW machine for offshore use.

The 5MW machines are not considered by Viking Energy to have a proven record yet. They are also a colossal weight. As windfarm supporter Bob Spanswick of con­struction barge operators Delta Marine said, the nacelle of the 5MW turbine weighs 350 tonnes, requiring a 1,000 tonne crane to lift it into place, compared with a 120 tonne nacelle for the turbines cur­rent­ly proposed by Viking Energy.

Although the new Vestas turbine may also be larger scale than the proposed Siemens 3.6MW machines, Viking has already allow­ed for extra height in its planning application by specifying its maximum turbine height at 145 metres to the tip of the blade. If the 3.6MW machines were eventually chosen they would not necessarily have to stand quite so high.

Mr Thomson said: “We built that 145m envelope deliberately to let us accommodate potentially more powerful machines. This could be an example of someone coming forward with something that con­veniently fits into our envelope. But it’s only a possibility.”


Get Latest News in Your Inbox

Join the The Shetland Times mailing list to get one daily email update at midday on what's happening in Shetland.