2 Methodology

The Greenhouse gases: HFCs, PFCs and SF6

The emission calculation is made in accordance with the IPCC guidelines (Intergovernmental Panel on Climate Change) /4/, and following the method employed in previous year calculation.

The methodology includes calculation of the actual emissions of HFCs, PFCs, and SF₆. In this calculation of actual emissions, the release from stock of greenhouse gases in products has been taken into account, and adjustments have been made for imports and exports of the greenhouse gases in products. Appendix 4 describes the specific emission factors, etc.

2.1 Scope and definition

The emission calculation of the actual emissions of HFCs, PFCs and SF₆ has over years become increasingly more comprehensive and accurate along with the development of internationally approved guidelines (IPCC Guidelines) and guidance (IPCC Good Practice Guidance) and the provision of increasingly detailed data.

The evaluation of the actual emissions includes quantification and calculation of any imports and exports of HFCs, PFCs, and SF₆ in products, and it includes substances in stock. This is in accordance with the latest and most accurate method of calculation (Tier 2) among the options provided for in the IPCC Guidelines /4/.

Estimation of Consumption and emissions

The calculation of consumption, emissions and stock were carried out on the basis of information from six sources:

Importers, agency enterprises, wholesalers, and suppliers
Consuming enterprises, and trade and industry associations
Recycling enterprises and chemical waste recycling plants
Danish Environmental Protection Agency
KMO, the Danish Refrigeration Installers’ Environmental Scheme
Previous evaluations of HFCs, PFCs and SF₆/2, 11, 13, 16, 25/.

Basis information for the present emission calculation is collected through questionnaire surveys combined with follow up telephone interviews.

The result of the project is primarily based on the information received from enterprise and importer respondents and information from KMO and Danish EPA is used as a supplement to verify parts of the collected data.

The information collected from importers and suppliers is compared with information from consumer enterprises in order to monitor any discrepancies between purchase and sales information and identify application of the use of substances. In some cases, the use of individual substances was estimated on the basis of two sources, since the majority of the consuming enterprises were known. In cases where not all enterprise end-users had specified the application area for substances, the consumption of individual substances was estimated on the basis of the information provided by importers, suppliers, and any trade and industry-related associations, such as KMO.

There may be inconsistencies between the information provided by suppliers and enterprise end-users. This is partly due to imports from other EU countries, changes in inventories of substances, or a lack of correlation between the quantities sold and the quantities consumed. It is also due in part to a certain amount of uncertainty in the method of calculation used by enterprises. However, sales and consumption information has been harmonised.

The estimated average degree of uncertainty in the report's consumption figures (quantities sold and bought) is about 10-15 per cent, and slightly greater for data regarding application areas. The degree of uncertainty in the calculation of actual emissions is estimated at 20-25 per cent, depending on import/export information for the specific products.

The calculation of F-gas emission is based on a calculation of actual emissions.

Actual emissions are emissions in the relevant year, accounting for the time lapse between consumption and emissions. Actual emissions include Danish emissions from production, from products during their lifetimes, and from the disposal of products. Actual emissions for the specific areas of application are determined on basis of the following approaches:

Tier 2 “Top-down” analysis

In the Tier 2 Top-down analysis, emissions are determined on the basis of information on consumption in the various areas of application and calculated or estimated emissions in the area of application (emission factors).

Tier 2 “Bottom-up” analysis.

In the Bottom-up analysis, the estimated emissions for a specific application area are based on information from producers using substances in production and in products; information on imports and exports of products; information on the technological developments within the application areas; information on the average amount of greenhouse gases contained in products; and information on the lifetime of products and actual emissions during their use and disposal.

Tier 2 bottom-up analysis were carried out within selected areas over a number of years. The analysis quantified the stock and, in some cases, Danish emission factors. Detailed analysis were carried out for commercial refrigerators, mobile A/C systems, fridges, freezers, and SF₆ power switches. Analysis were evaluated in separate reports /2, 11, 16/.

Bottom-up comprises:

Screening of the market for products in which greenhouse gases are used.
Defining the average content of greenhouse gases per product unit.
Defining the lifetime and the disposal emissions of products.
Identifying technological characteristics and trends of significance for emissions of greenhouse gases.
Calculating imports and exports on the basis of defined key figures, Statistics Denmark's foreign trade statistics, and information from relevant industries.

Results from this analysis have been expanded in the present evaluation of actual emissions.

As far as possible, the consumption and emissions of greenhouse gases have been evaluated individually, even though consumption of certain HFCs has been very limited. This was done to ensure transparency and consistency in time in the calculation of the sum of HFCs as their GWP value. However, it was necessary to operate with a category for "Other HFCs", as not all importers and suppliers have detailed records of sales of individual substances.

Uncertainty varies from substance to substance. Uncertainty is greatest for HFC-134a due to its widespread application in products imported and exported. The greatest uncertainty in the analysis of substances by application areas is assessed to concern the breakdown of consumption of HFC-404a and HFC-134a between commercial stationary refrigerators and mobile A/C systems. This breakdown is significant for the short-term (about 5 years) emissions calculations, but will balance in the long term. This is because the breakdown is only significant for the rate at which emissions are released.

Appendix 4 shows an overview of all application areas included with descriptions of the bases of calculation.

In Appendix 1, the table shows the F-gases covered by the Kyoto Protocol under the Climate Change Convention, including their chemical formulas and GWP values (Global Warming Potential).

2.2 Explanation of terminology

The following terms and abbreviations are used throughout this report:

Enterprise end-user: A producer that uses ozone-depleting substances or greenhouse F-gases in connection with production processes in the enterprise.
Emission factor: The factor used in the calculation of emissions from a product or a production process.
Consumption: Consumption includes the quantities of substances reported in Denmark in the year in question via imports from wholesalers and information from Danish producers.
Importer: Enterprises in Denmark that sell the relevant substances on the Danish market.
KMO: The Danish Refrigeration Installers’ Environmental Scheme
Stock: The amount of substance contained in products in use in Denmark.