Scottish Alliance for Geoscience, Environment and Society

Impact & innovation case study


Impact summary

  • Scottish government published tool in 2008
  • In-depth negotiations between academics, regulatory bodies & industry ensure tool is accepted by all
  • Long-term environmental impact
  • Provides a scientific basis on which development decisions can be made
  • Funded by the Scottish Government

SAGES member

Prof Jo Smith, University of Aberdeen and partners (Forest Research, the James Hutton Institute, the University of Edinburgh and the University of Glasgow).

Funded by the Scottish Government

Aim of the project

Windfarm-CAT is a tool for estimating potential carbon emission savings that can be achieved if windfarms are developed on peatland or forested land.

The tool estimates the “carbon payback” – the time required for net carbon losses associated with the windfarm to be balanced by carbon savings through clean energy.  Net carbon losses include loss of carbon from infrastructure, from carbon stored in peat and forest, loss of carbon-fixing potential of peatland and forest, and carbon savings due to habitat improvement.

The Windfarm-CAT, first published in 2008, enables planners to avoid developments on sensitive sites, while permitting developments with good management on sites where a windfarm does not result in degradation of sensitive soils. The latest version released in 2016 improves its user friendliness and better accounts for losses from forested land. New work is considering the impacts of repowering windfarms after a number of years operation to maintain and improve efficiency.


Since April 2011, all Section 36 onshore windfarm applications (over 50 MW) have used Windfarm-CAT to assess carbon losses.

This has now been translated into an on-line tool by Scottish Environment and Protection Agency (SEPA).

The key beneficiaries of this work are:

1. the windfarm industry which now has a tool that helps it demonstrate the environmental credibility of a proposed site and speeds up the planning process;

2. community groups and NGOs who have free access to a transparent methodology that allows cases to be made against unsuitable developments;

3. planning authorities who can quickly check the carbon payback time of a planned development;

4. wider society, which recognises the urgent need to reduce greenhouse-gas emissions by replacing fossil fuels, and now has a tool that ensures the envisaged benefits of windfarms are achieved.


The Scottish Government’s decision to publish the Windfarm-CAT online in 2008 attracted immediate attention from the national media, and transformed the politically sensitive debate over the development of windfarms on Scottish peatlands.  Carbon losses are now an integral part of the planning process, where previously they were not considered.

The development of the Windfarm-CAT has involved years of in-depth negotiations between academics, regulatory bodies (Scottish Executive, Scottish Environment Protection Agency, Scottish National Heritage), NGOs (RSPB, John Muir Trust, National Trust) and industry (Scottish Renewables, Scottish Power, Forestry Commission) to ensure the tool is accepted by all.

Windfarm-CAT will also have long-term environmental impact, discouraging developments on sensitive peatlands and protect sensitive habitats, while encouraging developments on already degraded sites and opening up opportunities for land restoration.

Calculation of the impacts of different management strategies encourages developers to use their financial resources to instigate peatland restoration and good practice to achieve a reduced carbon payback time. The extra resources available for restoration from the industry can have a positive impact on these habitats.

The research provides a scientific basis on which decisions can be made and has contributed rationale to debates where preconceived ideologies often cloud judgement.

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