Tuesday, 23 August 2011

Kilgallioch wind farm # 1

This is a first of a series of posts about large wind farm developments under consideration by the Energy Consents and Deployment Unit (aka, the Scottish Government), and we start with Kilgallioch. To help you pinpoint its intended location, its the area in the centre of the map below - if you're not sure where this is, just click the minus button a couple of times:

View South Carrick Wind Farms in a larger map

What I'm really interested in doing here is to start to demonstrate the scale of these large scale wind farms and in this case, the sort of quantities of materials involved in their construction so you can judge whether you feel such developments are appropriate.

All of the figures quoted in this post have been extracted from the Environmental Statement submitted as part of the planning application. I have quoted the source of each statistic for those of you who may be sceptical about the numbers.

Turbine foundation slabs are each expected to require approximately 525 cubic meters of concrete and 77 tonnes of steel reinforcing (ES, vol 1, Chr 4, page 2, para 17). Now, let's say that a cubic metre of concrete weighs 2.4 tonnes (source), which means each foundation slab will require 1,260 (2.4 X 525) tonnes of concrete. With 132 turbines planned for Kilgallioch, the tower foundation slabs total 166,320 tonnes overall (132 X 166,320). Let's not forget the steel reinforcing, which comes to 10,164 tonnes (132 X 77). Totalling all of this up, we have 176,484 tonnes of materials for the turbine foundation slabs. Wow! I accept this amount may increase or decrease depending on ground conditions, but that is clearly a massive amount of materials and let's not lose site of the fact that the steel will have to be bought in by road, as will the cement for the concrete. Finally, if we are expecting 69,300 (525 X 132) cubic metres of concrete to be poured into the ground, that much material will have to be dug out first.

It is estimated that approximately 1,020,000 cubic metres of stone will be required for the construction (ES, vol 1, Ch 4, page 7, para 67) and yes, you read that correctly - 1 million and twenty thousand. Unfortunately, we have no information on the density of this stone, so we cannot turn this volume into a mass and will therefore just have to accept this figure as is. Now, this material isn't going to be shifted by road. Instead, 'borrow pits' will be used. These are essentially areas of ground that have been identified as consisting of the required grade of material, from which the desired materials will be extracted as required. Upon completion of the works, 6 of the 8 eight identified borrow pits will be backfilled and partially contoured (ES, vol 1, Ch 4, page 7, para 71). So, having extracted the materials that are required the borrow pits will be 'landscaped' with materials to hand (presumably that'll be the 69,300 cubic meters of material removed for the preparation of the foundation slabs).

Lastly, I'll have a quick look at what what will be required in terms of new tracks & roads. There will be (ES, vol 1, Ch 4, page 5, para 40):

  • 5.5 km of new spine road
  • 35.7 km of new primary track
  • 35.4 km of new minor track

Totalling that lot of, we have 76.6 km (or 47.5 miles) of new road/track.

So, is this the clean and green way forward for renewable energy? The quantities and volumes of materials that will be required to build the Kilgallioch wind farm are truly mind boggling. Don't forget, those concrete volumes and steel tonnages are just for the foundation slabs. In future posts, I will continue to look at the Environmental Statement in more detail, however in the meantime if you want to make your thoughts or feelings known with regard to this development, you will need to write to:

Energy Consents and Deployments Unit
Scottish Government
4th Floor
5 Atlantic Quay
150 Broomielaw
G2 8LU

or email representations@scotland.gsi.gov.uk. You may also like to consider lobbying your local MSP.