Scotland's Renewable Energy Blog

SPR organised a party from the No-Tiree-Array group to visit to Barrow-in-Furness to view the various off-shore Arrays  in Morecombe Bay

The report produced afterwards by Rob Trythall is reproduced here in full with permission and with no additions or alterations.

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Clare Jones, Sophie Isaacson. Iain MacInnes ,and myself were the party organized by SPR to visit to Barrow-in-Furness 25-28 Sept. This was to view the various off-shore Arrays  constructed, or being constructed, in Morecombe Bay, off Walney Island.

 Summary:-

 Visual  Impact:-

Day Time :
Massively negative.  The ‘Row’s of  London Gherkins‘ analogy is apparent.

Night Time :
At night, the Array resembled an oil refinery operating at night.Each turbine looked like a light-up Xmas Tree. This is a “major” Tiree issue. (Marine Scotland Scoping Opinion p19)

 Erroneous Visualisations:
 SPR visualizations shown in June 28 SPR’s Public  Information  Day were based on an unlikely turbine  foundation type .The probable foundation type is a 4-legged jacket structure which adds       significantly to the negative visual impact. Subject to tide etc this structure rises to about 15-20m above sea level

 Construction Issues :
Anchoring foundations ,and cabling, present considerable technological challenges,still to be overcome.

 Sound:
Audible sound in operation would appear not to be an issue, but will be an issue during construction.

 Employment Benefit :
The jury is still out.

 Barrow vs Tiree:
No comparison…..no contest !!!

Array Location:-

These Arrays are:-

(1)Barrow Offshore /30 X 3 MW turbines / Area 10 sqKm / closest 7 km  offshore/one offshore  substation

(2)Walney 1 and 2 / 2×51(102)X 3.6 Mw Turbines / Area 73 sqKm /closest 14.4km-furthest 24 km offshore /max blade tip to sea level approx 150m/2 off-shore substations

(3) Ormonde/30×5 MW turbines  /Area 8.7sqkm/closest 9.7Km furthest 14km off shore / max blade tip height approx 160m/one offshore substation.

(Note : Ormonde’s turbines are the largest “proven technology”  turbines deployed offshore. These turbines ( upgraded to 6/6.5MW) are the current proposed  ‘model- size ’  for Tiree Array, if consented.)

 
Walney Array(closest turbine 14.5km)

Reportage /Background:-

 DAY 1

But first we had fun getting off Tiree! Monday’s plane was full, so SPR booked us on Sunday’s ferry to link with the evening train to Glasgow. On Sunday it was blowing a hoolie, the ferry just made it into Tiree, and after a rough trip, entered Oban Bay, over an hour late, making catching the Glasgow train an intangible concept.. but we got there … hi-jacking a lift from Andy Wright!!

DAY  2

Monday morning we were picked up by Morna Cannon and Ralph Thornton of  SPR . First stop was Whitelee, outside Glasgow, SPR and  Europe’s largest windfarm is located on Eaglesham Moor just 20 minutes from central Glasgow. The windfarm originally 140 turbines, is under expansion to 215 units, over 80 sqkm, to generate 593 MW.

Whitelee is SPR’s UK control centre. Tiree Array, if consented, will be controlled from Whitelee. I found the windfarm an overwhelmingly, ugly, invasive intrusion upon open moorland. The visibility was superb with Tinto,the Galloway Hills, Arran and Goatfell  in clear sight. Winds were light

Whitelee

Thence on to Barrow via the M74.  It is 5 years since I was last on this stretch of the M74.  Current, and future, intensive windfarm development dominates. An outcome of the Scottish Government’s s 2005 report on ‘The economic impacts of wind farms on Scottish Tourism’ was apparent. One of this report’s major propositions is ‘displacement theory’. This can be articulated as follows:-transiting a windfarm area can provoke negative tourist reactions, particularly with regard to visual impact, but once transited, these negative reactions may diminish as an issue for the tourist transitee.

Developers will always offer displacement theory ie the capacity to move on, or get away from sighting turbines, as a premis to avoid mitigating negative visual impact. Displacement theory cannot, and does not, apply to Tiree tourism

Barrow:

Barrow in Furness is an industrial town. The town has a population of approx 55000 and its immediate hinterland approx 75000 . Its current unemployment rate is 4.1% compared to England’s national rate of 3.8%. Approx 3000 people are claiming job-seeker’s allowance. Major employer’s, include BAE at its nuclear submarine construction yard, Kimberley Clarke’s Paper Mill, Centrica’s gas fired power station. Morecombe Bay is the UK’s most significant off shore gas field with various rigs, and installations scattered around the Bay,some within the Arrays.

 The Ormonde Array is a unique concept, it is a ‘dual-fired’  Array ie when its wind turbines are not generating at full capacity, its gas turbines kick-in, to maintain load into the Grid.

 The Port of Barrow imports wood-pulp, and exports granite/limestone /aggregate. It is the home port for vessels transporting Japanese nuclear waste to the Sellafield Nuclear re-processing plant. The port has a draft of 7.5m maintained by lock gates. The tidal range in the channel is 10m/the tidal range offshore is about 8m

Beyond the port,in sight, is Heysham Nuclear power station, with the Lancashire coast, and Blackpool Tower in stark relief ,stretching into the distance.

Entering Barrow, the only sight of the off shore turbines was a short glimpse passing the Kimberley Paper Mill. To sight the Arrays, one passes over the Barrow estuary, a depressingly ugly, muddy, creek to Walney Island. It was only after crossing over the bridge to Walney Island, and to within 100m of the promenade, that any off-shore turbines could be sighted.

(View from aerial view-point over  BAE’s nuclear submarine  yard. The buildings in foreground are  51m high. The turbines in the background are approx 150m high/ 15km distant )

Walney Island ,pop approx 13000, is flat low lying, scrub, with a rocky foreshore still with its abandoned cracked sewage outlets in place,leading to a brown, and not too clean beach. The only semblance of any tourist industry,was a rundown caravan park. On closer examination it proved to be a static caravan site.

Upon our arrival, the immediate contrast between on shore and offshore wind farm development was apparent. This indicated that the  capacity to mitigate or minimise visual impact of an offshore windfarm is near as damn it, ZERO.  Ormonde Array’s first  row of 5MW turbines was 9.7km offshore. To use current patois, the turbines  ‘were right in your face’ !! Unlike on shore, at Whitelee, where undulating re-forested moorland offered some potential to mitigate visual impact.

The Barrow-Walney area is not pretty…it is not Tiree!!

It is possible to live, and go about one’s daily life, in Barrow-Walney, without sighting a single turbine, let alone an Array!  The contrast with Tiree is stark. SPR’s visualizations of Tiree Array show clearly that Tiree’s topography makes it impossible for anyone on Tiree to live, and go about one’s daily life, without sighting significant sectors of the proposed Array. This will be exacerbated at night time.

In the wind farm turbine debate, the developers will always offer ‘displacement  theory’ ie the capacity to move on or getaway from sighting turbines, as a methodology to mitigate negative visual impact. Displacement theory cannot apply to Tiree.

Re the Arrays: (a) The Barrow Array was a distinct entity, separated from the Walney and Ormonde Arrays.

(b) The 3 Arrays in immediate view, Ormonde /Walney1 /Walney2 combine to have a higher density of turbines than would be the case with the Tiree Array. Ormonde( 30 turbines in 8.7sqm)  is positioned in front of Walney1 and 2  (132 turbines in 73 sqkm) plus 30  in 8.7 sqkm.

(c) There is a gap, approximating to twice the Ormonde Array between it ,and the Walney Array, consequently the area of visual impact is therefore is 73 + 3×8.7 = 99 sqkm

(d) Combined Array is  162 turbines  in 99 sqkm.

(e)  Tiree array proposed 320 turbines in 362 sqkm.

The turbine ratio of these 3 Arrays is 1.6 compared to 0.88 for proposed Tiree, as proposed . The combined Array’s turbine density, in this small sector of the Arrays, was twice the turbine density of the proposed Tiree Array.

The furthest 3.5 MW turbine (a smaller unit than planned for Tiree) at 24 Km was clearly visible.

The closest Ormonde turbine (5MW) was 9.7km off-shore compared to 5km proposed for Tiree Array.

Note : Ormonde’s turbines are the largest “proven technology”  turbines deployed offshore. These turbines ( upgraded to 6/6.5MW) are the current proposed  ‘model’  for Tiree Array if consented.

Ormonde under construction

As with Tilley the turbines had greater, and lesser visual impact, depending on the time of day, and the prevailing light conditions.

Day 3:

Visit to DONG’s s construction site and offices. DONG ( Danish Oil and Natural Gas) is the developer of  Walney 1&2. (Note this was the construction site and not the O&M Base).

SPR confirmed from the outset that  “The construction and assembly on Tiree of windturbines , offshore substations ,offshore convertor stations or their respective foundations is ruled out …” ( SPR Scoping Request  Aug 2010) . This visit was very useful as it gave an insight into construction issues which will have a considerable input to some of the outcomes of Tiree Array, if consented. It highlighted the contrast between the developer planning, supervising , and controlling, via individually appointed  subcontractors, every aspect of the construction, as opposed to appointing one contractor on a turn-key basis. This contrast is apparent from the current threatened delay to the Greater Gabbard offshore wind farm as a consequence of a £300m million dispute between the developers (SSE and RWE npower) and the turn-key contractor Fluor.

 DONG executives,in their power point presentation, emphasized that offshore windfarms were a temporary solution to meeting energy requirements. This raises the very obvious Q re Tiree Array, if consented. If decommissioned after 25 years, what happens then?. No one is giving this Q any consideration.

Itemised  critique:-

 Day-light visual impact: 
Viewing period approx 15.00-19.00 hrs. Notwithstanding the proximate area’s depressing,and ugly industrial backdrop, the visual impact was massively negative. We were blessed with superb visibility, and varying light conditions  The latter hi-lighted the capacity of even the farthest turbine (22km) during our day light to emerge from  comparative obscurity to being  a starkly visible industrial structure, in clear relief on the horizon. We viewed the Arrays from 3 different viewpoints. None ameliorated, or mitigated, the negative visual impact. This was compounded by the Ormonde Array, in the foreground, having a 4 legged jacket foundation as opposed to the monopile of the Walney 1&2 turbines in the background ( see foundation discussion below). Our 4^th visualization viewpoint was at night time.

Donnie C stated in a recent AnT that “ .. a big visual impact isn’t necessarily bad just because it is man–made. An awe inspiring view can be man-made as well as natural, a testament to human skill and endavour “ .

There was nothing “ awe-inspiring” in the view offered by these Arrays. It was ugly, and depressing.

The foundations of the turbines in the foreground were “ jacket type” . This is the more likely foundation type for Tiree Array if consented. The visualizations presented by SPR to the Tiree Commubity on their 28June Public Info meeting were not of this type. It is of paramount importance that this issue is addressed and SPR be required to re-present visualization of the Array basis ‘jacket-type’ foundations

Winds were light. The Turbines were barely rotating, by evening had stopped.

Night-time visual impact :-
Viewing period from dusk to dark(19.00 -20.00 hrs). Massively negative and intrusive . The night time visual impact was infinitely worse than expected. At night ,the visual impact of the Array was  much more invasive than during the day. The visual impression was of an oil refinery at night, or a forest of lighted Xmas trees . Even Ralph Thornton of SPR was having difficulty rationalizing what we saw before us!!

Ormonde in the Crepescule

Sound: Inaudible.
Notwithstanding the light winds and therefore comparative slow rotation of the turbine blades, direct turbine sound from the Arrays was inaudible. This was not the case on shore @ Whitelee .Background noise from the Arrays mainly came from a construction boat working within the Array .  There were several helicopter movements during our visit . There were several take-offs, and landings, from the nearby Walney Airfield . This is owned and operated by BAE and averages 5 flight movements/day. BAE utilizes it to move staff around the UK.( SPR take note .. we cud have flown direct to Barrow !!! )

Infrasound;
continues to be an on-going issue. Infrasound is sound lower in frequency than 20 Hz cycles per second, the “normal” limit of human hearing. It is characterized by an ability to cover long distances, and get around obstacles with little dissipation.There is on going research into impacts on the human and marine environment.

 O&M:
We did not visit an O&M base. SPR, prior to this visit, had advised that the  O&M strategy is derived, mainly, from the guarantee terms the developer negotiates with the turbine manufacturer. Examples given by SPR varied from 2-to 5 years. SPR reconfirmed this over-arching perspective during this visit. This turn offers a further insight into the current Tiree On-Shore-Mapping exercise ie whatever the outcome it  has to be derived from a tri-partite debate (1) Tiree Community presumably supported by some statutory authority (2) the developer (SPR) and (3) the turbine manufacturer eg Siemens /Gamesa etc. This explanation goes some way to explain why the O&M strategy for Tiree Array is a post consent issue, and why the current onshore mapping exercise, currently,is no more than an assessment exercise.

O&M at Walney is shore based working from day-boats. Day boats are chartered in through the maintenance subcontractor(s)

 Wave height:
At Walney the wave/swell  height restriction for boat- to- turbine transfers, is limited to 1.5m. Anything in excess of this height, then boats are re-called to base. This was the case on our visit, with the skipper of a boat returning shore- side with a swell forecast height closer to 2m. (This skipper was memorable for his haircut !! In his earlier life he had been the base guitar player for Shakin’ Stevens.)  The contrastwith Tiree Array is self evident  its mean swell height of 2.5m. The Carbon Trust has recently short listed 13 research projects to  allow safe boat to turbine transfer in wave /swell heights in excess of 3 m. Anything in excess of these heights favours adopting the within Array O&M strategy portrayed on the SPR info board at SPR’s  28 June public information day . This provides minimum inter-action with Tiree ( MS Scoping response p78 ).

 Foundation Types;
- The 2 Arrays in view contrasted the 2 basic foundation types namely monopile vs jacket . The latter is the most likely option to apply to Tiree Array,if consented. This has a significant contrast in visual impact .This is not the foundation type shown in SPR visualisations. 

Tiree must demand that SPR re-present their Tiree Array visualisations based on jacket foundations:-

 The Array’s negative night –time visual impact was far greater from  jacket foundation type turbines than monopile .

Monopile Type:-

Note:- These are library images of the Arrays viewed on our  visit.

The nature of Tiree Array’s bedrock will require these foundations to be drilled into the bedrock. There is little experience, or success in this regard. Both foundation types at Barrow were hammered ,or pile driven, into the Morecombe Bay seabed,  which is essentially ‘soft-bed’ mud and clay.  There is no rock on Walney. Some the positions (6 pcs) showed hard seabed. The developer (DONG) hired drilling equipment, but it was not used. All 102 positions ware ‘hammered’ as planned.

Gravity Type:-
The alternative foundation type is “gravity“. This can offer the partial profile of a monopile turbine above sea surface but requires massive dredging of the seabed, to level it to less than a 1m variation in height .  SPR indicate this foundation type may not be an option for Tiree Array eg:-

Alternatively as gravity type foundations deployed on the Thornton Bank Array (30Km off the Belgian  Coast)

 
HVDC Converters:
Two of these HVDC converters were within the  Arrays we  viewed.  These  are significant structures. Up to 4 of them  could be  positioned  within the Tiree Array. There is significant negative visual impact  pollution  from these structures particularly at night .

Scouring Protection /Foundations/ Cable anchoring:-
Around the base of the ‘foundation’, due to tidal movement, scouring can occur.  In  existing Arrays large scour holes have developed, often 1 m to 2 m deep, in some cases more. The have been known to ‘lower’ the turbine!! To prevent this occurring  various methods of  scour protection are adopted . Currently his is achieved by depositing a barrier of aggregate several metres high the monopile foundation base.

This applies to  monopile foundations pile driven into what I will call soft ground .This will not apply to Tiree Array as they will be drilled into rock. But an issue of foundation security may arise if,due to storm conditions, lose rock is moving around

Cable anchoring is also achieved in the same way ie overlayered with aggregate.  This is not a practical option for Tiree Array, if consented . What  is currently under consideration is 12 ton bags of granite rock, lowered onto, and to cover, the Array cables . SPR concede the perfect solution has yet to be derived, and developments in the Pentland Firth Tidal Power Project will have a considerable input to deriving any solution.

Many technical issues remain unresolved with regard to any possible construction of a Tiree Array

Marine Habitat:-
Dong put considerable emphasis on the Walney Arrays improving the local marine environment . Dong’s Marine Co-ordinator , a master mariner with 12 years experience fishing shell fish off Greenland, emphasized that the artificial reefs created by the scouring and cable protection, had enhanced local ‘ pot fishing’. On understanding that the Tiree Array, if consented, would not add reefs, but would be built by destroying and/or damaging an existing highly productive reef, he conceded  any gain to Tiree shell fishing would be unlikely. 

 Employment:-
It has to be remembered that we were visiting the developer’s construction site offices with the project very close to completion. A lot of people had left. The main positions were held by Danish head office personnel, who lived temporarly in the Barrow area. (Intriguingly all of them had chosen to live outside Barrow, furthest away from the windfarm, with not a turbine in sight!!!)

Some locals had been trained-up, but it appeared the employment opportunities were limited, and either low skilled, or easily acquired skills eg a marine operations assistant had come from hotel management!! The local unemployment statistic of 4.1% does not suggest that off-shore wind farm development has made a significant contribution to reducing local unemployment.

What was not identifiable was the employment created /sustained by any subcontracting directly into Barrow’s industrial hinterland. Such indirect employment opportunities will not apply to Tiree Array, if consented.

ACTION REQUIRED :-

(1) SPR  to present night time visualisations of existing day time visualisations.

(2) SPR to present further set of visualisations of  6MW and 10MW turbines  with jacket foundations, in both day and night light conditions.

NTA would like to thank SPR for the opportunity to visit these Arrays

NTA believes that all images in this article are free for use, but if  this is not the case, please contact NTA  at contact@n0-tiree-array.org.uk  and we will remove it

LINKS

No Tiree Array Website 

SPR Argyll Array site