Carbon-calculating: the development of Scottish Windfarms
Submitting InstitutionUniversity of Aberdeen
Unit of AssessmentAgriculture, Veterinary and Food Science
Summary Impact TypeEnvironmental
Research Subject Area(s)
Environmental Sciences: Soil Sciences
Engineering: Environmental Engineering
Summary of the impact
The Scottish Government is aiming to generate all of its electricity
through renewable energy sources by 2020. Research by the University of
Aberdeen has produced a freely available tool - the Windfarm Carbon
Calculator - that has overhauled the planning process for windfarm
developments in Scotland. In changing public policy and planning
regulations, and informing the public debate, Aberdeen's calculator is
helping the Government fulfil its pledge to become "the green energy
powerhouse of Europe" while protecting some of the country's most
environmentally fragile areas. It continues to guide the actions of
politicians, planners, the wind industry, NGOs and community groups.
The claimed impact therefore is on: the environment, economy and
commerce, public policies and services, practitioners and services.
The Scottish Government is promoting electricity generation by renewable
sources to meet its target of 100 per cent renewable electricity
generation by 2020. Windfarms situated on peatlands, usually located on
exposed sites and less productive than managed mineral soils, offer high
energy returns and reduced investment costs. However, one hectare of
peatland can contain 5,000 tonnes of carbon (http://www.newscientist.com/article/dn9722-grouseshooting-popularity-boosts-global-warming.html).
Installation of wind turbines can rapidly decompose peat, releasing carbon
into the atmosphere, thus lengthening the time for carbon payback and
destroying sensitive wildlife habitats.
Research at the University of Aberdeen led by Jo Smith, Professor in Soil
Organic Matter and Nutrient Modelling, coincided with an increase in the
mid-2000s in plans to develop windfarms on peatlands without considering
the carbon emissions cost. The importance of soil carbon to total
greenhouse gas emissions was highlighted in a seminal paper lead by
Aberdeen researchers in 2005, on emissions of greenhouse gases from
European soils, one of the first to provide dynamic simulations of changes
in soil carbon across Europe . Carbon losses from organic soils were
identified as a key uncertainty because these soils hold large amounts of
carbon and so, if poorly managed, have potential to emit large quantities
of greenhouse gases. The findings inspired a £500,000 grant  from the
Scottish Executive (SERAD) to develop a new model ECOSSE (Estimating
Carbon in Organic Soils - Sequestration and Emissions) to quantify
greenhouse gas emissions from organic soils.
Simulations using ECOSSE [2,3] revealed the scale of the potential threat
to Scottish peatlands and high potential carbon emissions that could
result from widespread conversion of Scottish peatlands. The data revised
estimates for carbon stored in organic soils in Scotland and Wales upwards
by 30 per cent for Scotland and 20 per cent for Wales. Recognising an
urgent need to factor potential greenhouse gas emissions into planning
applications for windfarms, the Scottish Government provided further
funding  for Aberdeen to design a simplified model that
could be used to calculate emissions at each proposed site.
Led by Jo Smith, University of Aberdeen researchers and their partners
created a carbon calculator for estimating potential carbon emission
savings that can be achieved if windfarms are developed on peatland or
forested land [4-6]. The methodology estimated the carbon payback time for
the windfarm; 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 calculator, published
in 2008, enabled 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. Developments to the
calculator continue - the latest version was released in 2011 - and will
improve its user friendliness and take into account further extraneous
factors like the impact of sheep grazing, housing and road construction.
Other lead Aberdeen academics were Dr Dali Nayak, Research Fellow
(2007-present), and Pete Smith, Professor of Soils & Global Change
(2001-present). Aberdeen led the research, receiving scientific input from
the James Hutton Institute (formerly Macaulay Institute); Forest Research
and the Universities of Edinburgh and Glasgow.
References to the research
 Smith JU, Smith P, Wattenbach M, Zaehle S, Hiederer R, Jones RJA,
Montanarella L, Rounsevell MDA, Reginster I, Ewert F. (2005). Projected
changes in mineral soil carbon of European croplands and grasslands,
1990-2080. Global Change Biology, 11, 2141-2152. (cited 104
times on WOK).
Regional scale simulation of changes in soil carbon with climate and
land use change
 Smith JU, Coleman K, Gottschalk P, Bellarby J, Richards M, Nayak D,
Hillier J, Flynn H, Wattenbach M, Aitkenhead M, Yeluripurti J, Farmer J,
Chapman S, Towers W, Bell J, Milne R, Thomson A, Skiba U, Evans C, Bradley
I, Whitmore A, Falloon P, Smith P. (2010). Estimating changes in national
soil carbon stocks using ECOSSE - a new model that includes upland organic
soils. Part I. Model description and uncertainty in national scale
simulations of Scotland. Climate Research, 45, 179-192. A new
model developed at the University of Aberdeen to simulate carbon and
nitrogen dynamics in peat soils as well as in mineral soils and a range
of scales from plot to regional.
 Smith, JU, Gottschalk, P, Bellarby, J, Chapman, S, Lilly, A, Towers,
W, Bell, J, Coleman, K, Nayak, DR, Richards, MI, Hillier, J, Flynn, HC,
Wattenbach, M, Aitkenhead, M, Yeluripurti, JB, Farmer, J, Milne, R,
Thomson, A, Evans, C, Whitmore, AP, Falloon, P, Smith, P. (2010).
Estimating changes in national soil carbon stocks using ECOSSE - a new
model that includes upland organic soils. Part II. Application in
Scotland. Climate Research, 45, 193-205. Application of the
new model to Scotland.
 Nayak, DR, Miller, D, Nolan, A, Smith, P, Smith, JU, (2010).
Calculating carbon budgets of wind farms on Scottish peatlands. Mires
& Peat 4, Article 09, http://www.mires-and-peat.net/.
Full description of the carbon calculator for windfarms on peats that
has been adopted by Scottish Government in planning.
 Smith, JU, Graves, P, Nayak, DR, Smith, P, Perks, M, Gardiner, B,
Miller, D, Nolan, A, Morrice, J, Xenakis, G, Waldron, S, Drew, S. (2011).
Carbon implications of windfarms located on peatlands - update of the
Scottish Government Carbon Calculator tool. Scottish Government Final
Report, CR/2010/05, pp. 69. Development of the carbon calculator
to include detailed forestry management on windfarms.
 Smith, JU, Nayak, DR, Smith, P. (2012). Avoid constructing wind farms
on peat. Nature 33(489). Application of the carbon calculator
to determine the impact of predicted future conversion to a low carbon
economy on the carbon savings possible when siting windfarms on peats.
-  ECOSSE project, Scottish Executive (SERAD), Dec 2003 to Nov
-  Validation of changes in soil carbon stocks in Scotland and
use of data to develop the ECOSSE model, Scottish Government (RERAD), Sept
2007 to July 2008. £89,855
- Calculating carbon savings from windfarms on Scottish peatlands
- revision of guidelines, Scottish Government (RERAD), Oct 2007 to Jan
- ECOSSE 2, Welsh Assembly Government, Jan 2009 to Apr 2009.
- QESM Methane, NERC, Apr 2009 to Dec 2009. £47,000
- Pilot project to determine the suitability of integrated
administration and control system (IACS) data to provide land use change
data for annual greenhouse-gas emission estimates, Scottish Government
(RERAD), May 2010 to July 2010. £45,523
- Carbon implications of windfarms located on peatlands - update
of the SG carbon calculator tool, Scottish Government (RERAD), Oct 2010 to
Aug 2011. £50,002
Details of the impact
The Scottish Government's decision to publish the University of
Aberdeen's windfarm carbon calculator online in 2008 [a] attracted
immediate attention from the national media, and transformed the
politically sensitive debate over the development of windfarms on Scottish
peatlands. Carbon calculations are now an integral part of the planning
process, having progressed rapidly from a point where carbon
considerations did not factor in the conversation, even though the impetus
for windfarm construction is powered by global pledges to reduce
The development of the calculator has involved years of in-depth
negotiations between the Aberdeen academics and 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. There are five key beneficiaries;
Smith has communicated with all main parties through regular meetings. The
windfarm industry has a tool that helps it demonstrate the environmental
credibility of a proposed site and speeds up the planning process,
evidenced by the successful application for Freasdail Windfarm in 2012
[f]. Community groups and NGOs have free access to a transparent
methodology that allows cases to be made against unsuitable developments.
Planning authorities can quickly check the carbon payback time of a
planned development. Wider society, which recognises the urgent need to
reduce greenhouse-gas emissions by replacing fossil fuels, has a tool that
ensures the envisaged benefits of windfarms are achieved. The Scottish
Government has been able to claim on its website that it is "a world
leader in advancing new scientific research on the carbon impact of wind
farms on peatlands, as part of our wider drive to promote best practice
for energy developments" [j].
The controversial 103-turbine wind farm in Shetland - the third biggest
in Scotland - received government approval in April 2012. The calculator
informed three years of wrangling between developers Viking Energy [b] and
community groups like Sustainable Shetland [c] opposed to the plans.
Following carbon calculations, in September 2011 Viking agreed to scale
back its proposals, reducing the number of turbines from 150 to 127. But
Ministers went further and granted consent for only 103 turbines, which
still provided an estimated £30m in annual income for the local community,
according to BBC news. The case encouraged the Scottish Government to fund
amendments to the windfarm carbon calculator and energy minister Fergus
Ewing launched a revised model in June 2011. He issued a requirement that
all new windfarm Section 36 planning applications must use the calculator
"for assessing carbon losses and savings" in developments that generate
50MW of electricity or more [d]. Ewing said: "Planning authorities, like
all public bodies, have a duty to take account of the emission effects of
their decision-making, and they should encourage developers to use the
carbon assessment tool for all wind farms on peat as a matter of good
practice" [g]. The Government is considering an extension of the
regulations to smaller sites.
The long-term environmental impact of the decision is clear: developments
on sensitive peatlands are avoided and sensitive habitats protected.
Furthermore the carbon calculator has opened up opportunities for land
restoration. Calculation of the impacts of different management strategies
of windfarm sites encourages developers to use their financial resources
to instigate peatland restoration and good practice to achieve a reduced
carbon payback time. If developments are focused on disturbed sites, extra
resources available for restoration from the industry can have a positive
impact on these habitats. But Aberdeen's research also provides a
scientific basis on which decisions can be made; it has contributed
rationale to debates where preconceived ideologies often cloud judgement.
The carbon calculator encourages developments on peatlands that are not
sensitive. For example, Black Law windfarm in Lanarkshire is sited on an
area previously used for mining so the damage resulting from the
development is much reduced. Aberdeen's research was cited in a Sunday
Herald article [e] in July 2008 to support criticism of a call by Scottish
Conservative MEP, Struan Stevenson, to ban wind farms from all peatlands.
His opponents, including Scottish Renewables, accused Stevenson of `bad
science', quoting Smith's published paper and referencing the carbon
Further research published in Nature by Smith has shifted the
public debate further . Based on new calculations the academics assert
that all developments on pristine peatlands should be avoided [h]. The
recommendation was made in a letter to Nature and covered by the Daily
Mail and The Press and Journal. The John Muir Trust has used
this to support its lobbying for a Wild Land Designation in Scotland. The
Scottish Government is considering the allocation of further funding to
Aberdeen to explore how the calculator can be adapted to assess wider use
Claimed impact as defined by REF therefore is that: the Aberdeen work
has had an impact on public policy and services by stimulating public
debate, through changes to regulations and through implementation of new
technology, the Carbon Calculator. It has impacted practitioners and
services that have used the research findings in conducting their work.
Further, it has had an impact on the environment by planning decisions
being informed by the work.
Sources to corroborate the impact
[a] The Scottish Government, 2008. Calculating carbon savings from wind
farms on Scottish peat lands - A New Approach. http://www.scotland.gov.uk/Resource/Doc/229725/0062213.pdf
(accessed 27/11/12). 1st publication of the carbon calculator on the
Scottish Government website.
[b] Viking energy, 2010. Environmental impact statement. Appendix A16.6.
Carbon payback calculations. http://vikingenergyfiles.opendebate.co.uk/files/Appendix-A16.6-Carbon-Payback-Calculations.pdf
(accessed 22/05/12). Viking Energy carbon payback calculations for
planned site on Shetland - calculations done using the carbon
[c] Sustainable Shetland, 2010. Carbon payback.
(accessed 22/05/12). Sustainable Shetland's rebuttal of the Viking
Energy carbon calculations.
[d] The Scottish Government, 2012. Wind farm savings on peatlands.
(accessed 22/05/12). Latest Scottish Government advice on calculating
carbon payback time.
[e] Sunday Herald, 2008. Ban on building wind farms on peat bogs is `bad
(top of the article gives publication date as 2006 but this is incorrect -
it's 2008; accessed 24/05/12). Reports in Sunday Herald opposing
amendment to European directive on renewable energy by MEP Struan
Stevenson that included a moratorium on building wind farms on peats
[f] RES, 2012. Freasdail Windfarm Development. http://www.freasdail-windfarm.co.uk/the-project/environmental-impact-assessment.aspx
(accessed 27/11/12). Environmental impact statement from Freasdail
Windfarm including calculations provided by the carbon calculator.
[g] Business Green, 2012. Scotland launches wind farm carbon calculator.
(accessed 24/05/12). Industry article on how the carbon calculator
will help the planning process.
[h] Smith, JU, Nayak, DR, Smith, P. (2012). Renewable energy: Avoid
constructing wind farms on peat. Nature Correspondence.
Comment on constructing windfarms on peats.
[i] Windfarms on healthy peatlands should be avoided, say carbon experts.
(accessed 26/11/12). John Muir Trust opinion piece on constructing
windfarms on peatlands.
[j] Scottish Government web-site on wind farms and carbon.