Camilty Wind Farm - Partnerships for Renewables

Camilty Wind Farm
6.4.6 On this basis, and on the assumption that the proposed wind farm’s annual output is
46.46GWh, a wind energy development of this scale is expected to displace approximately
19,979 tonnes of CO 2 emissions per year being emitted to atmosphere. These figures are
derived as follows:
46,463,040 kW (output) × 430 gCO 2 /kWh ÷ 1,000,000 = 19,979 tonnes CO 2
or to replicate the Renewables UK calculation (assuming full capacity)
(20.4 MW x 0.26 x 8760 x 430)/1000 = 19,979 tonnes CO 2
6.5 Carbon Payback
6.5.1 A key environmental benefit of the proposed wind farm is the generation of electricity from a
renewable energy source that will reduce or avoid the use of fossil fuels through the
displacement of electricity generated from other sources of energy.
6.5.2 It is widely recognised that wind farms save carbon emissions during operation when
compared to fossil fuel energy generation, as shown above. However, carbon losses and
gains during the construction and operation of the wind farm need to be evaluated on a sitespecific
basis.
6.5.3 Protecting and retaining the substantial reserves of carbon held in Scottish soils is an issue
recognised by the Scottish Government. Scottish Natural Heritage (SNH) produced a
Technical Guidance Note in 2003 for calculating carbon ‘payback’ times for wind farms.
Nayak et al. updated this guidance and devised a carbon balance tool for wind farms being
constructed on peat and forestry which considers the effects of wind farms during
construction and operation on soil stability and long-term greenhouse gas emissions.
6.5.4 The carbon balance of the proposed wind farm was calculated in accordance with the
Scottish Government recommended methodology: Calculating Carbon Savings from Wind
Farms on Scottish Peat Lands – A New Approach (Nayak et al. 2011).
6.5.5 Where possible, site-specific information was used to populate the parameters of the Carbon
Calculator. In order to inform the requirement for site-specific information a sensitivity
analysis of each of the main parameters in the carbon calculator was undertaken. This
process established which of the parameters has the greatest influence on the payback time
(i.e. the most sensitive) and therefore those parameters for which it would be preferable to
obtain site-specific data.
6.5.6 Appendix 6.1 provides full details of the sensitivity analysis carried out for the carbon balance
assessment. In some instances it was not feasible to obtain site-specific information due to,
for example, timescales required to obtain data. In this case publicised data was used to
populate the calculator in accordance with the Carbon Payback Calculator: Guidelines on
Measurements available from the Scottish Government (2011d). Two alternative turbine
models were run, to allow for a “worst case” and “best case” in terms of energy generated
compared to land take. However, the Payback time remained the same for both models, due
to differences in capacity factor of the turbine models.
6.5.7 Table 6.1 shows the calculated payback time associated with the proposed wind farm. The
results of the carbon calculator are presented in full within Appendix 6.1.
March 2013 6-6 ES Chapter 6
Climate Change and Atmospheric Emissions
Copyright Partnerships for Renewables Development Co. Ltd 2013 ©