The Crown Estate controls leasing of the seabed for offshore windfarms around Scotland.  There are ten exclusivity agreements for offshore windfarms in Scottish territorial waters (waters within 12 nautical miles or approximately 22km of the coastline), two large zones for offshore wind development in Scottish offshore waters (beyond 12 nautical miles), one deep water demonstrator project and one operational offshore windfarm in the Solway Firth.  For a map of these developments, please see The Crown Estate’s website here.

The Argyll Array site covers an area of approximately 360km².  Within this site, the exact area which we will apply for permission to build upon will depend on further site investigations to determine any environmental, social or technical constraints.

The Argyll Array site has the potential to generate anywhere between 500MW to 1800MW of clean green energy - enough to power 270,000 to 1,000,000 households.  The final MW capacity to be built will depend on the area for which permission is granted, as well as technical constraints (e.g. electrical grid connection limitations).

The number of turbines proposed has not yet been decided.  This will depend on the maximum capacity (MW) of the site for which permission is granted and the maximum power of the turbines to be installed.  If 6MW turbines were used, 100 would be required for each 600MW of the project, or 300 for all 1,800MW.  A common turbine being installed around the UK in 2010 is a 3.6MW turbine, in which case 500 would be required to generate the same 1,800MW.

The Scottish wave and tidal resource is huge, but the technology has to catch up to the maturity of wind technology. The exclusivity ScottishPower Renewables has with The Crown Estate is for investigation of the potential for a wind farm only. 

A number of permits are necessary to develop an offshore windfarm in Scotland.  We intend to submit our application for all permits in first quarter of 2012.  We shall present the results of assessments to relevant consultees including the Tiree public in advance of finalising the application for permission.

The Scottish Government has committed to determine applications for renewables developments within nine months in cases where there is no public inquiry.  Marine Scotland, a new Scottish Government department, will now play a large role in the permitting of offshore wind in Scotland.  It aims to streamline the consenting procedure for these developments.

The Scottish Ministers will make the final consenting decision for the Argyll Array offshore windfarm.  Permission for certain onshore elements of the project may be determined by Argyll and Bute Council.

If the Argyll Array project receives consent, it is expected that construction would commence in 2015.  However, this date is dependent on the time taken to prepare for and receive permission to build the project.

In the current system, ScottishPower Renewables would not be permitted to build, own or operate the electrical connection from the project to the national transmission system.  This would be done by an ‘Offshore Transmission Operator’ (OFTO), the identity of which would be determined after a 12 – 18 month tendering process run by Ofgem.  For more information on Ofgem, please see here.

Although ScottishPower Renewables cannot build the connection, we do intend to apply for planning permission for the connection infrastructure (i.e. for a cable route and AC/DC converter stations), and then, if we are successful, to transfer any such permissions to the OFTO.  However, under the current regulations the OFTO could choose not to use these permissions.  If the OFTO does so, they would still have to seek planning consent in the usual manner for what they intend to construct. 

Given the distance to the Scottish national transmission system, it is likely that the electrical connection will be by high voltage direct current (HVDC) and a mixed onshore/ offshore route.

This date is dependent on the time taken to prepare for and receive permission to build the project, as well as the time taken to construct the project.  Construction will be over several years but power would be exported to the grid as turbines are installed and commissioned. It is hoped that the windfarm would be fully operational by 2018.

If the project receives consent, construction is hoped to commence in 2015.  By this time, ScottishPower Renewables expect there to have been advances in offshore wind turbine technology.  Taking this into account, the current expected range of turbine power outputs is 3.6 to 10 MW, with associated tip heights 130 to 200 metres (from sea level to tip of the highest blade).  The tip of the blade is relatively small, and from a distance, the nacelle at the top of the tower is a larger visual reference.  These would be at a height of 80m to 115m.  The Skerryvore lighthouse off Tiree is 52m high, and the width of its tower at the narrowest point (just under the light) is similar to the width of turbine towers.  Tilley the Tiree community turbine has a 55m hub height and a tip height of 77m.  However, as Tilly has the benefit of a hilll about 20m above seal level, for comparison purposes this turbine has an effective hub height and tip height of 75m and 97m, respectively, above sea level. 

The manufacture and installation of the project is a £5.4 billion opportunity for industry.  The infrastructure required to manufacture, install and operate the project is additional opportunity.  The ongoing operations and maintenance will require a long term suite of local services and expertise as the project design life will be 20 – 25 years.

A range of economic opportunities would result from the project.  These include work in the following fields: environmental and technical surveys, vessel hire, windfarm construction, windfarm operations and maintenance, port/harbour improvements, onshore office/warehousing/domestic housing construction, cable laying and wind turbine/foundation manufacture. 

ScottishPower Renewables expect this work to be spread across companies and individuals throughout the UK and abroad.  However, we expect that a number of operations and maintenance jobs will be created on Tiree itself.  This number will depend on a range of factors, currently being investigated, including the size of the windfarm and the operations and maintenance strategy. 

One might expect a team of 100, from technicians and vessel captains to warehousing staff to be required to manage the operations of a 300 turbine project.  Additional services would be needed from industry for specialist ad hoc work and repair of components.

We will be undertaking a thorough consultation process throughout the development of the Argyll Array site.  There will be direct communications with the maritime and fishing industries to determine potential impacts and, where necessary, agree mitigation solutions.  During construction, appropriately sized exclusion zones will be sought to manage the health and safety of all concerned.  During normal operations the only navigation restrictions will be at the physical location of the foundations and a 50m safety zone around each.

The turbines will have a 20 to 25 year design life but much of the infrastructure could be for more than that (subsea cables).  A technical evaluation will be undertaken towards the end of the turbine life, and a replacement programme may occur, facilitating generation of clean power out to 50 years or more. Many of Scotland’s hydro electric projects are 50 and 60 years old now due to an adequate maintenance and replacement programme.

Section 105(2) of the Energy Act 2004 requires the Secretary of State to approve a project’s decommissioning programme in advance of construction taking place.  Best practice currently requires all elements of the windfarm posing visual, sea-use or environmental impacts to be removed.  In addition a financial security arrangement is agreed to ensure there will be sufficient funds to facilitate the decommissioning.

Well sited windfarms do not pose a significant threat to birds. To date, there have been no major adverse effects on birds associated with windfarms in the UK. An article in the journal ‘Nature' reminds us that the greatest threat to wildlife in the UK is climate change; the RSPB predicts that without a comprehensive network of renewable energy sources, climate change is predicted to detrimentally affect most species within the UK.

There is no evidence to suggest that windfarms have a negative effect on tourism.  In fact, the opposite is often found to be the case and many developers of onshore windfarms have been asked to provide visitor centres next to their sites.  A MORI poll in Scotland carried out in 2002 showed that 80% of tourists would be interested in visiting a windfarm. 

A 2008 study into the economic impacts of windfarms on Scottish tourism (‘The Economic Impacts of Windfarms on Scottish Tourism’, Scottish Government 2008), found that tourist impressions of windfarms remained positive, with 39% of respondents stating that windfarms had a positive effect on the landscape and only 25% stating that windfarms had a negative effect on the landscape.  However, it should be noted that these studies were in relation to onshore wind projects. 

The 2008 Scottish Government study notes the lack of published work on the impact of offshore windfarms on tourism, but highlights a case study from Nysted in Denmark.  Visitor numbers at the Nysted camping site have increased over the last ten years despite the fact that it is situated on the coast with a view to a large offshore windfarm.   Additionally, Nysted Tourist Information has been arranging boat trips to the windfarm since 2003, and these have seen considerable interest. 

Yes.  Windfarms do not emit carbon dioxide but instead provide clean and renewable energy, unlike conventional power stations, which emit 170 million tonnes of CO₂ each year.  If we are to meet legally binding government targets of cutting these figures by 80% by 2050, then we need a source of energy that does not produce carbon dioxide.

The average onshore wind farm in the UK will pay back the energy used in its manufacture within six to eight months.  The Argyll Array is likely to take a little longer but over its life will still pay back multiples of its energy input.

In extremely rare circumstances, some interference to analogue TV reception is possible.  The UK switch to a digital television signal, to be completed in 2012, will reduce impacts further.  As the Argyll Array is not situated between a transmitter and TV viewers it will not affect their signal quality.  Neither will it affect any signals received from a satellite.

In the UK, wind turbines produce useful power for 70-85% of the time.  The comparison of total power output over a year, compared with the scenario of a turbine operating at full power for the full year, is termed a capacity factor.  Typically in the UK this is 27% though it may be as high as 50% in very high wind areas.

Measured in terms of mechanical efficiency, a wind turbine is over 40% efficient whilst a coal fired power station is about 38% and a typical internal combustion engine is 20-25%.  A 1MW wind turbine will produce 1 MW of electricity at its rated wind speed (perhaps thirty miles per hour).  Were it to be 100% mechanically efficient it would have produced 2.5MW.  However Betz' law says that you can only convert less than 16/27 (or 59%) of the kinetic energy in the wind to mechanical energy using a wind turbine.

For further technical details please refer to http://guidedtour.windpower.org/en/tour/wres/betz.htm

This is unlikely.  It is possible to stand underneath a turbine and hold a conversation without having to raise your voice.  The evolution of windfarm technology over the past decade means that mechanical noise from turbines is almost undetectable, with the main sound being the aerodynamic swoosh of the blades passing the tower; noise levels from windfarms are on a par with rural background noise.

Any planning permission for a windfarm would contain a planning condition to ensure that noise levels are controlled to an acceptable level.

The Royal Institute of Chartered Surveyors have undertaken studies to assess if there is an effect on house prices due to the construction of a windfarm.  In general the survey shows that the largest drop in house value is at the time of the planning application, as is the case with any major development.

House prices appear to recover after the windfarm has been constructed.  Detached houses have been shown to have the most immunity to decreasing prices.

This survey can be read here.

In general, the cheapest electricity in 2010 is from efficient new gas fired plant.  Onshore wind energy is one of the cheapest forms of renewable energy but in general is more expensive than gas fired plant. Offshore wind is relatively more expensive than coal or nuclear, due to the larger civil engineering input plus methods/ limits for access.  Energy from the wind is likely to become cheaper in the future as the technology develops, and the fuel itself - the wind – will always remain free, sustainable and not subject to foreign politics.

In October 2009, OFGEM, the UK energy regulator, published major research (Project Discovery - Energy Market Scenarios) examining four possible energy scenarios to 2020. They concluded that in the longer term electricity prices must increase in real terms, due to our ever increasing reliance upon imported gas from eastern Europe and Russia.

But they found that a strategy to develop low carbon forms of generation (a balanced mix of nuclear and renewables) not only helped to tackle climate change, but was by far the cheapest option for UK consumers - in fact reducing increases by 2/3rds compared with an alternative scenario.

Renewable UK are in the process of updating various factsheets.  Links to relevant ones will be added to this FAQ sheet as they are available.

No turbines will be any closer than 5km to the coastline.