Open letter to sign and share about the applicability going forward of carbon calculator for windfarms on peat

Green__Jenny

Thanks to the 160+ people who’ve so far signed this open letter to Calderdale Council Climate and Environment Team. Please will more of you do so, if you agree?

To sign the letter, you need to use this google form – please enter your first and last name, and the first 4 characters of your postcode. Your details will not be made available publicly but will only be seen by the addressee, Calderdale Council Climate and Environment Team.

Why is there a carbon calculator for wind farms on peat?

The big reason for building onshore wind farms is so they can speed up the decarbonisation of the National Grid – helping the UK to reach Net Zero by 2050, and so helping to keep global warming below 2C by then.

But building wind farms on peat is fundamentally dodgy from the point of view of reducing carbon emissions and mitigating climate change. This is because of the potential for releasing the peat’s stored carbon to the atmosphere and so making climate change worse.

In order to assess this risk for individual proposed windfarms, over a decade ago the Scottish Government commissioned the development of a carbon calculator for wind farms on peat. It has now commissioned a review of the calculator’s applicability going forward, which is due to conclude in June.

The calculator’s only as good as the data that developers enter – Rubbish in: rubbish out

The Calderdale Wind Farm Ltd developers plan to use this calculator to work out the proposed wind farm’s carbon impact – and in their Scoping Report they said they would not revise their calculations even if the Carbon Calculator’s updated.

To calculate the windfarm’s carbon impacts on the peatland, the developer has to input hundreds of bits of data about the proposed wind farm and its impacts on the peat during construction, operation and decommissioning.

One of the issues being evaluated in the Scottish Government’s review of the calculator is the difference between the carbon impacts figures produced by developers when applying for planning permission, and the carbon impacts in reality once the windfarms are operational. Peat experts have noted developers can input optimistic data that give positive carbon results.

Much of the data comes from site-specific peat surveys, that the Local Planning Authority requires the developer to carry out. It’s vital that the surveys are sufficient to generate the necessary data, and that the inputs into the calculator are accurate.

The open letter asks what this means for the accuracy of the proposed windfarm’s carbon impacts figures

It’s not just a question of whether or not the wind farm’s carbon benefits would outweigh carbon losses over its lifetime – although this is the measure Calderdale Wind Farm mentioned in its Scoping Report.

More importantly, the carbon calculator can show whether the Walshaw Moor site would generate the greenest (lowest carbon) electricity possible, when compared to other potential non-peatland sites across England, where the carbon costs of a windfarm would be far lower.

(Spoiler alert: it wouldn’t. Wind farms on non-peat soils would produce fewer carbon emissions per unit of electricity generated than the proposed Wind Farm on Walshaw Moor, because they wouldn’t increase carbon emissions through damage and disturbance to the peat.) 

To measure this, the carbon calculator can work out what’s called the ‘carbon intensity’ of a windfarm. (This is the weight in grams of the carbon emissions produced for each kilowatt/hour of electricity generated.)

Carbon intensity is the most crucial measure for testing claims that the wind farm would help reach net zero and keep global waming below 2C by 2050. Often Scottish wind farm scoping reports include an initial calculation of carbon intensity. But Calderdale Wind Farm hasn’t. Why not?

Here’s the open letter

C/o changingmorethanlightbulbs@gmail.com
HX7 8HQ
22nd December 2023

To: Calderdale Council Climate and Environment Team
Copied to: Richard Riggs, Calderdale Council Planning Officer

Dear Calderdale Council Climate and Environment Team,

OPEN LETTER – the Scottish Government’s Carbon calculator for wind farms is currently under review in order to determine whether it is fit for purpose going forward

Please reconsider your agreement with Calderdale Wind Farm Ltd that the current version of “the Scottish Government’s Carbon calculator for wind farms on Scottish peatlands is an appropriate tool to use to calculate the carbon impact of wind farm developments on peatland in the UK.”

The Scottish Government itself is unclear about this.

On behalf of the Scottish Government, Edinburgh University’s CarbonXChange has commissioned a research project to assess the evidence for “the applicability of the carbon calculator tool for windfarm development on Scottish peatlands and other carbon rich soils”

This research, based on the most recent and up to date information, will fully review the current operation and application of the calculator, provide a recommendation on whether it is fit for purpose going forward and, if necessary, recommend whether changes are needed to improve its accuracy.

The research conclusions and recommendations will be made in June 2024.

Among other things, the analysis is to evaluate proposed versus realised parameters from existing wind farms, and should address accuracy in calculations of:

  • loss of peatland’s carbon sequestration potential,
  • emissions associated with peat loss, disturbance and handling during construction,
  • emission abatement through restoration, and
  • emissions associated with the windfarm itself, e.g. turbine life cycle, and the electricity mix in the grid, and consideration as to how to handle this in the future;

With such significant uncertainties about whether the current version of carbon calculator is fit for purpose going forward, and what changes might be needed to improve its accuracy, we do not think it is appropriate for Calderdale Council Climate and Environment Team to uncritically endorse its use by Calderdale Wind Farm Ltd. Particularly since the Calderdale Wind Farm Ltd Scoping Report says that, “following any further update of the Carbon Calculator that may occur…it is not expected for there to be any requirement for the Carbon Balance assessment to be amended post-submission.”

What if the review were to conclude that the current version isn’t fit for purpose? And recommends changes to improve its accuracy?

More information about the review of the Scottish Government Carbon Calculator is attached, in support of our request that you reconsider your agreement with Calderdale Wind Farm Ltd that, as it stands, “the Scottish Government’s Carbon calculator for wind farms on Scottish peatlands is an appropriate tool to use to calculate the carbon impact of wind farm developments on peatland in the UK”.

Even the Scottish Government isn’t sure the the current version is fit for purpose.

Regards,

Here’s where you can sign in a google form

Just click on this link, and then add your name and first 4 characters of your postcard in the google form:

https://docs.google.com/forms/d/e/1FAIpQLSdQDH4BBtlEcjxFejySo3BcTBbGK0-fZSgQiqSwuPTqGCHdtA/viewform

Here’s the attached additional information in support of the open letter

There are three main aspects of the Scottish Government’s review of its Carbon Calculator for wind farms on Scottish peatlands that have caused us to ask you to reconsider its appropriateness for calculating the carbon impact of wind farm developments on peatland in England:

  • By 2035, we can’t see that the carbon payback time output produced by the Carbon Calculator in respect to emissions from different power generating sources will have any relevance – and the Scottish Government Review is considering its accuracy and how to handle it in the future.
  • The Carbon Calculator’s accuracy in showing the wind farm’s impact on peat carbon stocks is compromised by the problematic quality of data that some developers enter into the calculator.
  • Despite advances in the science of peat drainage and peat restoration, longer term research is needed in order to gather better data, eg about the impact of tracks on peat, that will allow more accurate calculation of a wind farm’s impact on peat carbon stocks. This will take years.

In preparing this summary of our objections, we have been been grateful for advice and information from various experts, but what follows is solely our responsibility and views.

1. By 2035, we can’t see that the carbon payback time output produced by the Carbon Calculator in respect to emissions from different power generating sources will have any relevance.

The Scottish Government’s review of the Carbon Calculator’s applicability includes the electricity mix in the grid, and consideration as to how to handle this in the future.

As things stand, we think the carbon payback measure based on the electricity mix in the grid will be irrelevant after 2035.

We can’t see the point of this as a means of indicating whether or not the proposed Calderdale Wind Farm would contribute to net zero decarbonisation targets.

The national grid is already on track to reach the UK government’s 2035 target for all electricity to come from 100% zero-carbon generation. If Calderdale Wind Farm Ltd were given planning permission, it could easily be 2030 or 2035 by the time it was operational.

By then, calculation of the wind farm’s carbon payback time on the basis of its CO2 emission saving over grid-mix would of course show that the wind farm’s CO2 emissions savings over the zero carbon grid-mix would be non-existent.

If the carbon payback measure based on the electricity mix in the grid is irrelevant after 2035, as seems likely, the only pay-back of the carbon losses associated with windfarm construction and peat disruption will presumably be carbon gains from peat restoration.

Instead, we think that the Carbon Calculator’s output ‘Ratio of CO2 eq. emissions to power generation (g/kWh)’ – aka carbon intensity – would be a more useful measurement for the developers to use, to show how green the energy produced by Calderdale Windfarm would be. This figure can be used to help identify the most suitable sites for wind farms – which the Scoping Opinion requires (p5).

2. The big problem with the Carbon Calculator is the quality of data that some developers enter into the calculator in order to show the wind farm’s impact on peat carbon stocks

This is the focus of the ClimateXChange/Scottish Government review of the accuracy of the Carbon Calculator, and the factors that may limit its accuracy.

Both peatland drainage data and peatland restoration data are key to calculating how a wind farm affects peat carbon stocks.

Prof Jo Smith, one of the carbon calculator’s authors, has told us the carbon calculator’s methodology for quantifying carbon losses from the construction, operation and decommissioning peatlands is sound. The problem is with the inputs used, particularly uncertainties about the extent of peat drainage caused by construction of turbines and access tracks. It’s a case of “rubbish in – rubbish out”.

As reported in The Ferret, Prof Jo Smith agrees with the review of the carbon calculator. Her view is that the science has moved forward and new information could help reduce two key uncertainties about wind farms’ impact on peat carbon stocks: the extent of peat drainage and the the effectiveness of different methods of restoration. This means that the entered value for the time taken for restoration can now be more accurately estimated – if data entered by developers is accurate.

But although the science of peat restoration has moved on, developers don’t always take any notice.

Richard Lindsay’s Critical Review of the Lewis Wind Power Environmental Impact Statement documents identified the need for developers to use well-established scientific methods and theories for assessing key issues such as the character, condition and potential impact of the wind farm for the peatland habitat.

The Critical Review said developers’ failure to do so resulted in the absence of some basic information needed to estimate potential environmental impacts on the peatland habitat, from construction and operation of the proposed development.

Clifton Bain, the International Union for Conservation of Nature (IUCN) UK Peatland Programme Director, has pointed out that a current problem with the calculator is that if developers invest in restoring peatland, the calculator allows them to judge what figures to put into the mix for that; this can make the difference between a wind farm that appears viable in terms of the ratio of carbon gains to carbon loss at the site, and one that is totally unviable.

Clifton Bain told The Ferret that he’d seen estimates on restoration potential using very high figures whereas estimates on damage seem to use low figures.

The problem of developers’ optimism bias is also indicated in Richard Lindsay’s critical review of Lewis Wind Power Environmental Impact Statement. It criticises the lack of worst-case scenarios in the documents, despite the fact that “ecological responses and interactions mean that it is often important to consider worst-case events, and to consider them in an integrated way.”

These problems will apparently be addressed in the Scottish Government/CarbonXChange review of the Carbon Calculator’s fitness for purpose. Until then, it seems developers can make it say what they want, depending on the accuracy or not of the figures they input

One suggestion is that the calculator’s accuracy in calculations that show the ratio of carbon gains to carbon loss at the site would be improved by standardised numbers. This would mean that developers can’t let their optimism bias influence their judgement about what figures to enter for restoration potential and estimates on damage. Solving the problem identified by Prof Jo Smith, of “rubbish in – rubbish out.”

The John Muir Trust in Scotland thinks an increase in the accuracy of the carbon calculator’s assessments of emissions from peatland caused by drainage would help to protect peatlands. The Trust has urged haste in the review process, because the calculator has been ‘in review’ for nearly two years and in the meantime wind farms are proceeding on peatlands which they believe are worthy of more protection as a natural carbon store.

Regarding peatland restoration, the John Muir Trust has told us the possible carbon savings should be treated with caution if there is nobody checking that these savings are actually occurring. Confidence in the calculator’s accuracy could also be improved if the results submitted by applicants were scrutinised and checked by an authority/independent body.

But in England, which organisation would have that responsibility?

Professor Jo Smith has told us that in Scotland it is left up to the Scottish Environmental Protection Agency to ensure that restoration of the water table is demonstrated, when developers claim this as evidence of restoration of the actual damage to the peat caused by the construction of a wind farm.

This is crucial because, as Professor Jo Smith clarified, in its approach to identification of carbon gains at the site (excluding the electricity generated), the Carbon Calculator assumes that once a site is drained, the volume of peat affected by the development will all be lost unless it can be demonstrated the actual damage caused by construction of the wind farm was restored.

The losses of peat are assumed to stop at the time the peat is demonstrated to have been restored. This means re-establishing the water table so that the speeded up decomposition of peat occurring under aerobic conditions is stopped. Full restoration (ie where vegetation is re-established) is nice – but less important as the annual input of carbon from vegetation is usually much smaller than the losses of carbon from having drained the peat.

3. Longer term research is needed in order to gather better data – eg about the impact of tracks on peat – that will more accurately calculate a wind farm’s impact on peat carbon stocks

Better data for peat drainage from wind farm construction requires site specific surveys “over seasons, even years”, according to an Independent Review of the Carbon Impact Assessment of the Strathy South wind farm by Rebekka R.E. Artz and others.

They say that applying the Scottish Government Carbon calculator’s methodology for calculating the distance affected by drainage would require a site-specific “measured parameter.” Surveys to determine this measured parameter (to input into the carbon calculator) “have to take into account antecedent weather conditions and ideally should be conducted over an extended period (seasons, even years).”

Relatedly, the ClimateXChange specification for the Carbon Calculator review says that the updated Scottish Government National Planning Framework 4 has set out the need for “a detailed site specific assessment…to identify the likely net effects of the development on climate emissions and loss of carbon.” (Policy 5). The “detailed site specific assessment” will be required to identify:

i. the baseline depth, habitat condition, quality and stability of carbon rich soils;
ii. the likely effects of the development on peatland, including on soil disturbance; and
iii. the likely net effects of the development on climate emissions and loss of carbon.

However, site-specific assessment is difficult as noted by the Energy Isles Wind Farm Carbon Balance Assessment using the Scottish Govt Carbon Calculator. For example, in calculating the distance affected by drainage, dry soil bulk density on the site was used as a parameter to estimate the average drainage distance – but this is “a very difficult parameter to measure on site.”

There is a need for longer term monitoring of impacts of tracks on peatlands – Dr Jessica Williams, Policy Lead, IUCN UK Peatland Programme, has told us this is required, as “There is a lack of research from the UK on track impacts unfortunately.” Her Review of the effects of vehicular access roads on peatland ecohydrological processes points out that “Changes to [peat] composition can occur rapidly as a result of a stochastic event, after long time lags.”

The critical review of Lewis Wind Power EIS by Richard Lindsay and others agrees with the need for more long term monitoring of peatland tracks: “No supporting scientific literature is cited in relation to either rockfill or ‘floating’ roads. This is because very little has been published about the long-term behaviour and environmental impact of such methods. In short, in environmental terms these selected construction methods are best described as ‘experimental’.”

The calculator is only as good as the data entered into it and if good data is not available, Prof Smith has advised us it is necessary to at least find evidence for the best and worst extents of drainage and to run both scenarios through the calculator to show the uncertainty in carbon payback times – the length of time the wind farm will take to begin generating emissions reductions after carbon losses associated with construction and peat disruption are ‘paid back’. In some cases, windfarms may never reach this point.

If, as we think, the carbon payback measure based on the electricity mix in the grid is irrelevant after 2035, the only pay-back of the carbon losses associated with construction and peat disruption will presumably be gains from peat restoration. And as Prof Jo Smith has said, peat restoration has a greater effect on stopping carbon losses than on sequestering carbon, since the annual input of carbon from vegetation is usually small.

Given these problems, the Scottish Government isn’t sure that the current version of the Scottish Government Carbon Calculator is an appropriate tool to use to calculate the carbon impact of wind farm developments on peatland in the UK – so why is Calderdale Council?

REFERENCES

1 Comment

  1. Pingback: Calculating the carbon impact of wind farms on peat – Save And Restore Walshaw Moor

Leave a comment