Study claims converter station would offset emissions in 49 days
The council is still no clearer as to when it will be able to hold another hearing into the proposed converter station at Upper Kergord which forms part of Viking Energy’s project for a huge windfarm in the isles.
Scottish Hydro Electric Transmission Ltd. (SHETL) last year applied for permission to build two large metal-clad buildings, each up to 150m long, 40m wide and 22m high, to house transformers and related electrical plant for the windfarm, along with a spare converter transformer.
In April this year the planning board deferred a decision on the application pending further information about the carbon impact of the development. Work was carried out on behalf of SSE and Viking Energy Ltd by consultants BMT Cordah, whose report claims the emissions caused by building the station would be offset in no more than 49 days.
Having received that information, the planning department has asked the Scottish Environment Protection Agency (Sepa) for guidance on whether the consultants’ findings could be verified because it does not have the in-house expertise to analyse the report. But in a letter to planners this week Sepa said it was still in the process of clarifying with the Scottish government its possible role as an advisory service on the carbon balance of new developments, the establishment of which “will be some time away”.
Planning official John Holden said the council would be keeping in touch with Sepa but – unless the section 36 consent application for the windfarm itself is determined in the meantime – there is little else the department can do to progress the converter application.
The consultants’ report estimates that the converter station – chiefly through the displacement of peat – could result in total losses of 131 kilotonnes (kte) of carbon dioxide, with an additional 16kte of carbon dioxide if the trench for a cable joined to the proposed interconnector cable between Shetland and the UK mainland is factored in.
The carbon dioxide savings of the windfarm, they estimate, could be 3kte of carbon dioxide per day based on the energy it generates replacing the carbon emissions of a fossil fuel mix of energy generation. That means it would take either 44 or, including the trench, 49 days to offset the carbon emissions caused by the converter station.
In a worst case scenario, the report claims, up to 50,000 cubic metres of peat could have to be extracted and the calculations “account for carbon dioxide emissions from lost peat as a result of excavation and discount the use of peat in restoration activities elsewhere”.
The report describes the estimate of carbon losses as “highly conservative” in assuming that the peat excavated is in “pristine condition, whilst in reality peat on the site will be variable in quality with large areas of modified and improved land”.
In a letter to SIC planners, SSE project manager Greig Taylor said the environmental statement “recognises that the Viking windfarm will contribute to carbon reduction in its generation of electricity from a sustainable source. At the time of application for the Kergord proposals the Viking application had not been made and the carbon payback figures could not be provided or therefore used in any detailed quantitative or cumulative assessment”.
Mr Taylor wrote: “Although these two projects are the subject of separate consent applications, neither project can go ahead without the other. The carbon losses associated with construction of the converter station can therefore reasonably be assessed as being offset by carbon savings associated with operation of the windfarm.”
Windfarm Supporters’ Group spokesman Chris Bunyan said the Viking Energy project appeared to be subject to more scrutiny than projects elsewhere in Scotland: “I don’t really understand why the Shetland planning officials seem to be so keen on digging a hole for themselves when other planning departments don’t have this problem in making decisions about large windfarms.”
But Sustainable Shetland vice-chairman Kevin Learmonth said he felt the SIC was taking a “reasonable approach” to the application and questioned the model, drawn up by the Macaulay Institute in Aberdeen, for assessing the carbon impact of windfarms.
“These projects are only being considered as a means of addressing carbon dioxide reduction,” he said. “If they can’t prove that they’re going to be substantially reducing carbon dioxide, there’s no point in doing them.”
He added: “The Scottish government [has] tendered for companies to do work on a revised carbon model for building windfarms on peat. That tends to suggest they are not entirely happy with the current model that’s there.
“It could be they think the figures can’t be relied upon at all, or it might be that the government is looking for a way out to avoid building windfarms on peat, because the figures might show it’s a net carbon emitter. It could go the other way because of industry lobbying, to re-jig the figures to get the answer that the industry wants.”