Site last updated on Saturday, October 20, 2007

The following figures are drawn from websites that outline other wind factory developments in the UK and give a fair indication of the logistical scale of the Western Lochaber project.

The most up to date 2 Mw turbines manufactured by Vestas Wind Systems A/S (to give only one example) have the following dimensions:

V80 type and V90 type.
Tower height (depending on situation) 60 - 67 - 78 - 100 mtrs.
Rotor Diameter V80 - 80 meters V90 - 88 meters
Tower weight 110 tons - 220 tons
Nacelle weight 61 tons all models.
Rotor weight 34 tons all models.

Total Weight 205 tons - 315 tons.

TURBINE TRANSPORT.
The Turbines can be delivered in component form. But the largest elements would be the one piece blades at 44 mtrs long each. Each Tower can be delivered to the site in segments. These are up to 4.5 mtrs in diameter and may weigh up to 25 tons each. They would be up to 25 mtrs in length. The Nacelle and associated machinery would be delivered in pieces and built up on site. The Hub itself weighs 19.5 tons.

Most of these Wind Turbine components require specialist transport vehicles. Moving loads of up to 61 tons and 44 mtrs in length along un-surfaced tracks is a specialist business. The Cranes required to assemble to towers have a built up weight of over 120 tons.

TURBINE TOWER FOUNDATIONS.
Turbines towers require foundations which are calculated depending on each individual site. They can vary in scale a great deal.

The largest (in this study) consist of an excavation 18 meters in diameter between 2.5 and 4.5 meters deep. This is filled with reinforced concrete till 1 meter below ground level. (180 - 200 cu.mtrs / Approx 300 tons.) Onto this base a reinforced column ring support is built up till marginally above original ground level. The ring itself is 4.5 mtrs in diameter. The tower is fastened by massive bolts to the ring. Finally the ground top soil is back filled to reinstate the landscape up to the base of the tower.

From the above it can be shown that approximately 600 tons of material could be required at each site.

TOWER CONSTRUCTION MATERIAL TOTALS.
Total of Materials to be imported to sites. Based on current proposals
For Morvern in excess of 60,000 tons.
For Ardnamurchan in excess of 150,000 tons.
For Mull in excess of 75,000 tons.

Construction totals can be further detailed as follows:

Because the sourcing of the hardcore/ballast material for the foundations could be done locally, a figure for quarried stone is required. This , according to the data given in the other projects studied, is often sourced from "borrow pits" adjacent to the sites.

Foundation ballast stone required, for Foundation concrete.
For Morvern 15,000 tons of stone would be required
For Ardnamurchan 37,500 tons
For Mull 19,500 tons.

Base Cement required .
For Morvern 5000 tons
For Ardnamurchan 12,500 tons
For Mull 6.500 tons

Steel reinforcement for the Foundations. (estimated)
For Morvern 5000 tons
For Ardnamurchan 12,500 tons
For Mull 6,500 tons

To process all this material (a) a quarrying plant and (b) a concrete mixing plant would be required at each location. The machinery involved at each location could weigh in excess of 1000 tons.

To transport the concrete to each site would probably involve lorries with a 20 ton carrying capacity. These would make a minimum of 15 journeys to each site. The "pour" of each foundation would be a continuous operation until completed. i.e. day and night.

ROADS, INFRASTRUCTURE.
The districts covered by the Wind Energy proposal are not currently served by any roads constructed to any UK or EEC major road standard. Safe axle weights for heavy vehicles using available local roads are far below national standards. Road alignment, grading, and road widths are inadequate for large vehicles.

The ideal spacing of turbines would place them at least 300 mtrs apart. It can be concluded, therefore, that around 1 km of service roadway will be required for every 3 turbines. This must represent around 30 miles of new tracks for Morvern, 70 miles for Ardnamurchan and 40 miles for Mull.

All road making machinery and all engineered components for bridges and culverts would have to be imported to the area. The list of machinery required to create 150 miles of new tracks across virgin hillsides and peat bogs, along with that required to excavate some 100,000 cu. mtrs of material from foundation pits, is a very specialist subject. The list must run to hundreds of machines.

Site Commissioning.

All the cabling, transformers, High Tension Connectors etc will have to be transported to site. In the proposal a network of Sub Sea cables is suggested. (NB this has not been addressed in this study.)

DELIVERY TO SITE.
Delivery of all of the components would have to occur by sea. (There are no adequate roads.)

The districts within the proposal are not currently equipped with any dock facilities to enable heavy freight movement of the sort and scale proposed. Existing facilities in Tobermory, Kilchoan and Lochaline are hardly suitable for the type of operations that would be involved. New dock, and dockside facilities , marshalling areas, assembly areas, hostels for the workforce, vehicle parks , site offices , and workshops for the machinery would all have to be prepared on the coast adjacent to each location. While some of this infrastructure might be achieved using temporary structures, the reinstatement of the landscape following the construction phase would be a massive undertaking.

SEA TRANSPORT.
The transport of the components by sea, from outside the region, might be achieved by the use of existing ships. However due to the tidal range around the coasts of the West Highlands specialist landing ships would probably be essential to enable rapid discharge of cargo.

CONCLUSION.
In view of the above factors it is impossible to conclude that an on shore development of the type proposed for Morvern , Mull and Ardnamurchan could ever be in financial terms more cost effective than an Offshore development of the same scale.

This study is based on such details as have been revealed by Wind Energy to various councils and individuals, details which have changed from time to time. No definite proposal has yet been made public.