© Cantium Energy Ltd 2016

On Farm Anaerobic Digestion Plant

Biogas Sustainability Audit

We appreciate that these audit requirements can be quite onerous, especially for smaller generators, those who operate intermittently or use fuel from a variety of sources. Therefore, we try to work as efficiently as possible to keep audit costs down and will offer a fixed price quote for any work.

Generating stations larger than 1MW capacity and using Solid or Gaseous Biomass to produce electricity may require an independent audit to comply with the ROO. There are exceptions for those generators using specific waste as a feedstock, such as sewage gas and landfill gas.


If a Sustainability Audit Report is required, then this must be submitted to Ofgem (the regulator) before the end of June, following the end of the relevant compliance year. In reality a report could be submitted later than this date but Ofgem will suspend the issuing of ROCs until an audit is approved, so delay can be costly.


How all the fuel used is derived must be considered for a Biogas Sustainability Audit Report but not all feedstock is treated the same. Certain wastes can be exempt from the emissions saving criteria and therefore an Audit Report can be quite complex for a station using a mix of different feedstocks from various sources. This might be the case for fuel derived from Anaerobic Digestion, for example.


Clearly, verifying the heritage of different feedstock consignments and calculating the relative contribution to energy production can be time consuming but we try at all times to maintain a common sense approach. We are confident that our Audit Reports represent excellent value so why not ask for a quote?



Bioliquid Sustainability Audit

Used Vegetable Oil fuel

Auditing for the Renewables Obligation

Complying with the terms of the Renewables Obligation Order for generators using Bioliquid and Solid / Gases Biomass fuels and claiming ROCs

Under the Renewables Obligation Order 2015 (ROO) any generating station that produces electricity wholly or partly from bioliquid, and claims Renewable Obligation Certificates for this output, must arrange a sustainability audit report at the end of each compliance year. A similar report is required for any station using solid or gaseous biomass as fuel to produce electricity, as long as the Total Installed Capacity of that station is 1MW or more.


Amongst a number of stipulations, the ROO requires that any Sustainability Audit Report must have considered the following issues:


1) Whether the systems used to produce the sustainability information are likely to produce information which is reasonably accurate and reliable


2) Whether there are controls in place to help protect the sustainability information against material misstatements due to fraud or error


3) The frequency and methodology of any sampling carried out for the purpose of obtaining or checking the data on which the operator relied in preparing the sustainability information


4) The robustness of the data on which the operator relied in preparing the sustainability information


5) Whether anything has come to the attention of the person preparing the report to indicate that the sustainability information is not accurate


6) Any audit should be to a recognised standard (essentially ISAE 3000 as this specifically mentioned in the ROO)


7) Whether the various calculations used to confirm the emissions saved can be substantiated.

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Whatever its Total Installed Capacity, a generating station using bioliquid fuel, and claiming ROCs, will have to have an audit. The date for submission to Ofgem is the last day of May (one month earlier than for biogas plants). Similarly to a biogas audit, failure to meet the submission date will mean that the issuing of ROCs will be suspended, so as the submission date is only two months after the end of the compliance year, an Auditor needs to compile the report quickly.


Bioliquid Sustainability Audits are potentially a little more straightforward than those for Biogas fuelled plants, as liquid fuel is less likely to derive from many different sources. However, the ROO still requires that the Audit Report considers emissions and the operator’s assessments of Greenhouse Gas (GHG) impacts must be checked. Unlike a biogas audit there is no exemption for bioliquid derived from waste in GHG calculations and there are benchmarks for the percentage of emissions saved (over fossil alternatives) which should be met. Waste liquids used as fuel may be exempt from the Land Criteria (the contribution to lifecycle emissions from growing a fuel) otherwise these must also be considered by the auditor.


As a Bioliquid Sustainability Audit is required for all generators using this fuel, the cost of the audit can be a significant burden. We recognise that all generators need an efficient service at reasonable cost and will consider individual circumstances in our fee quotation. Please ask us for a quote.