Commission Decision of 18 July 2007 establishing guidelines for the monitoring and reporting of greenhouse gas emissions pursuant to Directive 2003/87/EC of the European Parliament and of the Council (notified under document number C(2007) 3416) (Text with EEA relevance) (2007/589/EC) (repealed)

6. MEASUREMENT-BASED METHODOLOGIES

6.1. GENERAL

As set out in Section 4.2, greenhouse gas emissions may be determined by a measurement-based methodology using continuous emission measurement systems (CEMS) from all or selected emission sources using standardised or accepted methods once the operator has received approval from the competent authority before the reporting period that using a CEMS achieves greater accuracy than the calculation of emissions using the most accurate tier approach. Specific approaches for measurement based methodologies are laid down in Annex XII of these guidelines. Installations applying CEMS as part of their monitoring system are to be notified by Member States to the EU Commission pursuant to Article 21 of Directive 2003/87/EC.

The procedures applied for the measurement of concentrations, as well as for mass or volume flows shall, where available, be according to a standardised method that limits sampling and measurement bias and has a known measurement uncertainty. CEN standards (i.e. those issued by the European Committee for Standardisation) shall be used, if available. If CEN standards are not available, suitable ISO standards (i.e. those issued by the International Standardisation Organisation) or national standards shall apply. Where no applicable standards exist, procedures can be carried out where possible in accordance with suitable draft standards or industry best practice guidelines.

Relevant ISO standards include, inter alia:

• ISO 12039:2001 Stationary source emissions — Determination of carbon monoxide, carbon dioxide and oxygen — Performance characteristics and calibration of an automated measuring method,

• ISO 10396:2006 Stationary source emission — Sampling for the automated determination of gas concentrations,

• ISO 14164:1999 Stationary source emissions. Determination of the volume flow rate of gas streams in ducts — automated method.

The biomass fraction of measured CO₂ emissions shall be subtracted based on the calculation approach and shall be reported as a memo item (see Section 14 of this Annex).

6.2. TIERS FOR MEASUREMENT-BASED METHODOLOGIES

The highest tier level pursuant to Annex XII shall be used by the operator of an installation for each emission source which is listed in the greenhouse gas emissions permit and for which relevant greenhouse gas emissions are determined applying CEMS.

Only if it is shown to the satisfaction of the competent authority that the highest tier approach is technically not feasible or will lead to unreasonably high costs, may a next lower tier be used for the relevant emission source. Therefore, the selected tier shall reflect for each emission source the highest level of accuracy that is technically feasible and does not lead to unreasonably high costs. The choice of tiers shall be subject to approval by the competent authority (see Section 4.3).

For the reporting periods 2008-2012 as a minimum Tier 2 in Annex XII shall be applied unless technically not feasible.

6.3. FURTHER PROCEDURES AND REQUIREMENTS

(a) Sampling rates

Hourly averages (a valid hour of data) shall be computed for all elements of the emission determination (as applicable) — as laid out in Annex XII — by using all data points available for that specific hour. In case of equipment being out of control or out of operation for part of the hour, the hourly average shall be calculated pro rata to the remaining data points for that specific hour. In case a valid hour of data cannot be computed for an element of emission determination, as less than 50 % of the maximum number of hourly data points(1) are available, the hour is lost. For each instance where a valid hour of data cannot be computed, values for substitution according to the provisions of this Section shall be calculated.

(b) Missing data

Where a valid hour of data cannot be provided for one or more elements of emission calculation due to the equipment being out of control (e.g. in case of calibration or interference errors) or out of operation, the operator shall determine values for substitution for each missing hour of data as shown below.

(i) Concentrations

In case a valid hour of data cannot be provided for a parameter directly measured as concentration (e.g. GHGs, O₂), a substitution value C*_subst for that hour shall be calculated as follows:

With:

the arithmetic mean of the concentration of the specific parameter,

σ _{C_} the best estimate of the standard deviation of the concentration of the specific parameter.

Arithmetic mean and standard deviation are to be calculated at the end of the reporting period from the whole set of emission data measured during the reporting period. If such a period is not applicable due to essential technical changes at the installation, a representative timeframe, if possible with a duration of one year, shall be agreed with the competent authority.

The calculation of arithmetic mean and standard deviation shall be presented to the verifier;

(ii) Other parameters

In case a valid hour of data cannot be provided for the parameters not directly measured as concentrations, substitute values of these parameters shall be obtained through a mass balance model or the energy balance approach of process. The remaining measured elements of emission calculation shall be used to validate the results.

The mass or energy balance model and underlying assumptions shall be clearly documented and presented to the verifier together with the calculated results.

(c) Corroborating calculation of emissions

Parallel to emission determination by a measurement based methodology, annual emissions of each considered GHG shall be determined by calculation based on one of the following options:

(a)

calculation of emissions as laid down in the respective Annexes for the respective activities. For the calculation of emissions, lower tiers (i.e. Tier 1 as a minimum) can generally be applied or;

(b)

calculation of emissions as laid down in the 2006 IPCC Guidelines, e.g. Tier 1 methods may be used.

Deviations between the results from the measurement and the calculation approach can occur. The operator shall explore the correlation between results from the measurement and the calculation approach, taking into account that a generic deviation resulting from the two different approaches might exist. Taking this correlation into account, the operator shall use the results of the calculation approach to cross-check results from the measurement approach.

The operator shall determine and report in the annual emission report, relevant data where available or best estimates of activity data, net calorific values, emission factors, oxidation factors and other parameters used for the determination of emissions according to Annexes II to XI — using laboratory analyses where appropriate. Respective approaches as well as the chosen method for the corroborating calculation shall be laid down in the monitoring plan and be approved by the competent authority.

Where comparison with results of the calculation approach clearly indicates that results of the measurement approach are not valid, the operator shall use substitution values as described under this Section.

(1)

With the number of maximum hourly data points resulting from the measurement frequency.