Proposals for large scale wind farm developments in Scotland have raised concerns about the reliability of methods used to calculate the time taken for these facilities to reduce greenhouse gas emissions. Carbon (C) losses and gains during the construction and lifetime of the wind farm and the long term effects on the peat lands on which they are sited need to be evaluated. However, there is an increasing public policy demand for renewable energy given Scotland's commitments to reduce greenhouse gas emissions by reducing the use of fossil fuels for energy generation. There is a need for consistent and robust methods for the evaluation of C savings from wind farms. This project is part of a process of gaining a consensus view as to the scope and implementation of such a method. SNH and SEPA have supported the Scottish Government in managing this project and a wider body of stakeholders have been consulted at stages during the project, including field visits to operational wind farms, a workshop, and direct consultations on specific details of the work. This provided inputs and views on the approach devised to estimate C losses and savings from wind farms on peat soils in Scotland.
Soil protection and retaining the substantial reserves of C held in Scottish soils is an important issue for Scotland and recognised by the Scottish Government. SNH produced a Technical Guidance Note in 2003 http://www.snh.org.uk/pdfs/polstat/caf.pdf for calculating C 'payback' times for wind farms. This method did not take account of the wider impacts on the hydrology and stability of peat lands as its primary purpose was to determine impacts on peat land habitats. This project has re-visited the SNH Technical Guidance Note in order that the impacts of wind farms on soil stability and greenhouse gas emissions over the long-term can be taken into account.