| Bottom | | Front page |

Environmental Project No. 1284, 2009

The Greenhouse gases: HFCs, PFCs and SF6

Contents

Preface

1 Summary

• 1.1 Danish consumption and emission of F-gases
  • 1.1.1 Consumption
  • 1.1.2 Emission
  • 1.1.3 Trends in total GWP contribution from F-gases

2 Methodology

• 2.1 Scope and definition
• 2.2 Explanation of terminology

3 F-gas consumption

• 3.1 Import of substances
  • 3.1.1 HFCs
  • 3.1.2 Sulphur hexafluoride
  • 3.1.3 Perfluorinated hydrocarbons
• 3.2 Consumption by application
  • 3.2.1 Consumption of HFC refrigerant
  • 3.2.2 Consumption of HFC as foam blowing agent and as propellant
  • 3.2.3 Consumption of SF6
  • 3.2.4 Consumption of PFCs

4 Emission of F-gases

• 4.1.1 Emissions of HFCs from refrigerants
• 4.1.2 Emissions of HFCs from PUR foam products and propellants
• 4.1.3 Emissions of sulphur hexafluoride
• 4.1.4 Emissions of per fluorinated hydrocarbons

5 List of references

APPENDICES

• 1. GWP values for F-gases
• 2. GWP contribution from HFCs, PFCs, and SF6, 1993-2020.
• 3. Specification of methods and assumptions for emission calculation
• 4. Good Practice Guidance compliance in DK F-gas calculation 2007

Preface

On behalf of the Danish Environmental Protection Agency (Danish EPA), the consulting firm PlanMiljø ApS carried out the emission calculation of Danish emission of F-gases, 2007. The emission calculation is carried out in continuation of previous year emission calculations /13/ and references in these.

The F-gas emission calculation and reporting is assessed by Danish EPA and National Environmental Research Institute, Denmark (NERI) and the consultant. Further the draft report is send to central stakeholders for comments and general information.

The assessment group consisted of:

• Frank Jensen, Danish EPA
• Erik Lyck, Danish National Environmental Research Institute  (NERI), University of Aarhus
• Tomas Sander Poulsen, PlanMiljø ApS

Other central stakeholders, who are invited to comment the report:

• Lau Vørs, AKB Denmark (Authorized Refrigeration Installers Association)
• Torkil Høft, KMO
• Sven-Erik Jepsen, Confederation of Danish Industries (DI)

The objective of this project was to determine the Danish consumption and actual emissions of HFCs, PFCs, and SF₆ for 2007. Further, if methodology changes are made in connection to the work on 2007 data, the data for previous years are considered and updated accordingly.

The emission calculation is partly prepared to enable Denmark to fulfil its international obligations to provide data and information on F-gas emissions, and partly to follow the Danish trend in consumption and emissions of HFCs, PFCs, and SF₆. Examples of reporting of Danish emissions is given in reference /18, 19, 21, 23, 24/, and most recently, in reference /26/.

Greenhouse gases cause an increase in the ability of the atmosphere to retain surplus heat radiated from the earth. Consequently the temperature of the earth’s surface is rising and this leads to climate changes. There are several ozone-depleting substances that also have a strong greenhouse effect. These substances are regulated under the Montreal Protocol.

The potential effect of different greenhouse gases varies from substance to substance. This potential is expressed by a GWP value (Global Warming Potential). The so-called F-gases (HFCs, PFCs and SF₆) that do not have an ozone-depleting effect, but which have high GWP values are regulated by the Kyoto Protocol under the United Nation Climate Change Convention.

The Danish EPA has published a booklet on the ozone layer and the greenhouse effect /5/, and the Danish EPA has also published a report on substituting the greenhouse gases HFCs, PFCs and SF₆  /10/.

1 Summary

• 1.1 Danish consumption and emission of F-gases
  • 1.1.1 Consumption
  • 1.1.2 Emission
  • 1.1.3 Trends in total GWP contribution from F-gases

1.1 Danish consumption and emission of F-gases

1.1.1 Consumption

HFCs

In 2007, the total import (minus re-export) of pure HFCs and HFC blends was estimated to 403.2 tonnes. Compared to 2006, where total consumption was 558.8 tonnes, the import has decreased with 155.8 tonnes. The import of almost all HFCs are reduced.

The 2007 import of HFC-134a is reduced with 120 tonnes compared to 2006 with a total consumption of 160.7 tonnes. This substantial reduction is first of all coursed by more than 50% reduction in use of new refrigerants in commercial refrigeration system and in production of household fridges.

Import of HFC-404a is reduced with 46.5 tonnes compared with 2006, and the total consumption is 129.9 tonnes in 2007. The reduction is coursed by approx. 25% reduction of consumption in commercial refrigeration system.

Imports of HFC-407c were reduced with 20.1 tonnes to 50.5 tonnes in 2007. HFC-407c is a substitute refrigerant for HCFC-22 in refrigerators. Over the last decade there has been an overall increase in import of HFC-407c but in 2005 and now also 2007, the import was reduced. It might indicate that a number of older refrigeration systems are phased out.

The reduction in consumption of main refrigerants in 2007 (HFC-134a, HFC-404a and HFC-407) in commercial refrigeration system has been more than 185 tonnes from 2006 to 2007. It clearly emphazise the effect of the ban against installation of new HFC systems brought into force 1.1. 2007.

SF₆

The overall consumption of SF₆ in 2007 was approx. 5.4 tonnes. Consumption of SF₆ was used for power switches in high-voltage power systems and laboratories.

PFCs

The Danish consumption of PFCs (per fluoropropane) in 2007 was 0.7 tonnes. The PFC consumption in 2007 derives from to areas:

• optics fibre production
• refrigerants in commercial refrigeration

1.1.2 Emission

The GWP-weighted actual emissions of HFCs, PFCs, and SF₆ in 2007 were 884.4 thousand tonnes CO₂ equivalents and the emission has increased compared to 2006, where the corresponding emissions were 865.3 thousand tonnes CO₂ equivalents as reported in /24/.

The total emission in 2007 has increased for HFCs but decreased for SF₆. The emission of PFCs is almost the same as in 2006.

The increase in emissions for HFCs is in particular occurring from increased emissions of HFC-404a and increased emissions of HFC-134a from stock in  commercial refrigerants.

Emissions from reductions of HFC-134a in aerosol sprays and use of SF₆ in laboratories decreases from 2006 to 2007.

In Table 1.1, consumption, actual emissions and stock in products are summarised.

Table 1.1 Consumption, actual emissions, stock, actual emission and GWP contribution from greenhouse F-gases 2007, tonnes.

In Figure 1.1, The relative contributions of HFCs, PFCs, and SF₆ to the total emission in CO₂-equivalents are shown for application areas for 2007.

Figure 1.1 The relative distribution of GWP emissions, analysed by aplication area, 2007

The figure shows that emissions from refrigerants used in commercial stationary refrigerators account for the largest GWP contribution. These refrigerators cover 68.7 per cent of the total actual contribution in 2007. The major contribution is from HFC-404a.

The second-largest GWP contribution, accounting for 11.5 per cent, is emission from release of HFC-134a stock in insulating foam in fridges and freezers.

Emission of HFC-134a from mobile A/C contribute with 10.1 per cent and emission of HFC-134a and HFC-404a from transport refrigeration contributes with 2.3 per cent of the total GWP contribution.

The three sources of SF₆ emissions in 2007 were power switches, double glazing windows and laboratories/fibre optics. These account for 3.3 per cent of the total GWP contribution.

HFCs contribution is estimated to comprise  94.8 per cent of the overall GWP contribution in 2007, Emissions of SF₆ comprise 3.5 per cent and emissions of PFC contribute with 1.7 per cent of the total emission.

The relative distribution is shown in Figure 1.2.

Figure 1.2 The relative distribution of the GWP contribution from HFCs, PFCs, and SF₆, 2007.

HFC’s

Actual emissions from HFCs have been calculated to 838 724 tonnes CO₂ equivalents. In 2006, emissions were 833 600 tonnes CO₂ equivalents. It is an increase of approx. 5 100 tonnes CO₂ equivalents.

The actual emission from HFCs has increased to its highest level since HFCs has been monitored.

SF₆

Actual emissions have been calculated at 1.3 tonnes, equivalent to a GWP contribution of 30 347 tonnes CO₂ equivalents. In 2006, emissions were 36 000 tonnes CO₂ equivalents.

PFCs

The emission of PFCs origins from of PFCs in production of fibre optics and stock emission from commercial refrigeration containing HFC-413a. The total GWP-weighted PFC emission is 15 362 tonnes CO₂ equivalents.

1.1.3 Trends in total GWP contribution from F-gases

Figure 1.3 shows the trend in Danish GWP contributions from HFCs, PFCs, and SF₆ for 1992-2007. The differences from the present calculations of the total GWP value compared with earlier calculation methods are illustrated in the figure.

Figure 1.3 Trends in GWP-weighted potential, actual and adjusted actual emissions 1992-2007, 1.000 tonnes CO₂ equivalents.

The figure shows that the GWP emission has continued the increase started in 2001 and reached the highest level for calculation of actual emissions.

The development in the GWP contribution 1992-2007 can also be seen in Table 1.2 below.

Table 1.2 Total GWP-contribution from HFCs, PFCs, SF₆, 1992-2007determined according to the four different methods of calculation applied during this period, 1 000 tonnes CO₂ equivalents,

2 Methodology

• 2.1 Scope and definition
• 2.2 Explanation of terminology

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.
  

3 F-gas consumption

• 3.1 Import of substances
  • 3.1.1 HFCs
  • 3.1.2 Sulphur hexafluoride
  • 3.1.3 Perfluorinated hydrocarbons
• 3.2 Consumption by application
  • 3.2.1 Consumption of HFC refrigerant
  • 3.2.2 Consumption of HFC as foam blowing agent and as propellant
  • 3.2.3 Consumption of SF6
  • 3.2.4 Consumption of PFCs

3.1 Import of substances

An overall picture of the trends in imports of greenhouse gases is given in Table 3.1, based on information from importers for the years 1992, 1994-2007.

3.1.1 HFCs

HFCs were imported by five enterprises in 2007. One of the importers is consumer and use the imported substances in production of fridge/freezers. The company imports directly from other EU countries without using an agency.

In 2007, the total import (minus re-export) of pure HFCs and HFC blends were approx. 403.2 tonnes. Compared to 2006, where total import was approx. 558.8 tonnes, the import has decreased with total 155.8 tonnes. The import of almost all HFCs are reduced. It is only the import of HFC-507a and HFC-152a where there has been a small increase.

The 2007 import of HFC-134a is reduced with 120 tonnes compared to 2006 with a total import of 160.7 tonnes. This substantial reduction is first of all coursed by more than 50% reduction in the use of HFC-134a in new refrigerants in commercial refrigeration system and in production of household fridges.

Import of HFC-404a is reduced with 46.5 tonnes compared with 2006, and the total consumption is 129.9 tonnes in 2007. The reduction is coursed by approx. 25% reduction of consumption in commercial refrigeration system and reduction in use of HFC-404a refrigerant in transport refrigeration systems (from 6 tonnes in 2006 to 0.8 tonnes in 2007).

Imports of HFC-407c were reduced with 20.1 tonnes to 50.5 tonnes in 2007. HFC-407c is a substitute refrigerant for HCFC-22 in refrigerators. Over the last decade there has been an overall increase in import of HFC-407c but in 2005 and now also 2007, the import was reduced. It might indicate that a number of older refrigeration systems are phased out.

The reduction in consumption of main refrigerants in 2007 (HFC-134a, HFC-404a and HFC-407) in commercial refrigeration system has been more than 185 tonnes from 2006 to 2007. It clearly emphazise the effect of the ban against installation of new HFC systems brought into force 1.1. 2007

The only refrigerants, where imports have increased is HFC-410a and HFC-507a. The substances increased to 12.8 tonnes respectively 11.4 tonnes in 2007. In 2006, the imports were 7.7 and 6.1 tonnes. There is no clear explanation for this and it is assumed that the reason probable is ordinary diversion between seasons.

The import of HFC-152a was 13 tonnes in 2007. This is a smaller increase of the import from 2006. HFC-152a is used in thermostats.

3.1.2 Sulphur hexafluoride

Six importers reported having imported and sold 5.4 tonnes of sulphur hexafluoride in 2007. Sulphur hexafluoride was mainly used in power switches, but smaller amounts are used as an agent for plasma erosion in production of micro chips and in laboratories for analysis purposes.

3.1.3 Perfluorinated hydrocarbons

There has been an import of PFC-14 (CF₄) and PFC-318 (C-C₄F₈) of approx. 0.7 tonnes in 2007. The PFCs are used in production of optical fibres. This is a relatively new consumption area in Denmark and the consumption increase dispite the amount still is below one ton.

There has been a small import of 0.1 ton perfluorpropan C₃F_8,, which was contained in the blend refrigerant R413a (contain 8% PFC) used in commercial refrigerators.

Table 3.1 Developments in imports of greenhouse gases, tonnes.

Click here to see "Table 3.1 Developments in imports of greenhouse gases, tonnes".

Beside the import of substances stated in table 3.1 there is also an import of HFCs  for 100% re-export. This amount are not explicated in the table. To be mentioned is import and re-export of HFC-365 and HFC-245fa. The substances are used in Danish production of PUR system foam (semi manufactured articles). The production is only for export (use of HFC based PUR systems are banned in Denmark) and furthermore the production does not course emissions through the production process. The particular amount is therefore excluded for further calculation of Danish f-gas emissions. The amounts are known by DEPA.

3.2 Consumption by application

The evaluation of consumption divided into application areas is estimated on the basis of information from importers and producers, and on sales reports to the Danish Refrigeration Installers' Environmental Scheme (KMO). Table 3.2 shows consumption distributed according to application.

Table 3.2 Consumption of HFC distributed on application areas in 2007, tonnes.

There are no other known applications using HFCs in Denmark than those appearing in Table 3.2.

3.2.1 Consumption of HFC refrigerant

In recent years, the Danish consumption of HFC refrigerants points toward increased use of HFCs in commercial refrigeration and 2007 is no exception. In 2005 the import decreased for the first time, but 2007 show an increasing trend again. This is expected to stop in 2007 because the consumption of HFC refrigerants only will be to refilling of existing installations.

The general increase in HFC refrigerants in commercial systems is a natural consequence of the phase-out of air conditioners based on R-22 (HCFC). More over, commercial refrigeration with R-12 (CFC) and R-502 (CFC) were replaced by R-22 systems after 1995 when CFCs were banned in Denmark. This added to the percentage of refrigeration systems with R-22. The production of new R-22 systems was prohibited in 2000 and substitution with R-22 in existing systems was prohibited in 2002.

The use of HFCs as refrigerant in commercial refrigeration and stationary A/C systems is covering approx. 74 per cent of the total consumption in 2007. The most commonly used refrigerant in commercial refrigeration is still HFC-404a and HFC-134a.

Approx. 26 per cent of the HFC consumption is used in foam blowing and for other purposes than refrigeration.

The consumption of HFC-134a as a refrigerant in fridges/freezers was reduced in 2007 with approx. 2.5 tonnes compared to 2006. The decrease is not considered as an indication of a general reduction in the production in the Danish refrigeration sector but as an indication of that the sector has substituted to alternative refrigerants.

The consumption of refrigerants in vans and lorries for transport refrigeration has decreased slightly and is considered as a normal year to year movement. The consumption of refrigerants for mobile A/C systems has again increased this year.

Consumption by application area is based on information from producers and importers and on data from KMO, which receives reports of the sales of substances from refrigerator installers and automobile garages, etc. (only when drawing-off is more than 1 kg).

The consumption of refrigerants for household fridges and freezers is calculated on the basis of information from enterprise end-users.

The consumption figures for refrigerants in commercial and stationary A/C systems, and mobile A/C systems and refrigerators are estimated using data from KMO and information from importers as well as statistics on car imports.

Table 3.3 shows the consumption by weight of refrigerants according to application area.

Table 3.3 Consumption of HFC as refrigerants according to application, 2007.

Mobile A/C

D.A.F. (The Danish Automobile Dealers Association) publishes annual statistics of the number of vehicles in Denmark /17/. These data form the basis for the calculation below of HFC-134a stock in Danish vehicles. Calculations also include a calculation of the proportion of A/C systems installed in vehicles, still undergoing servicing, and therefore still refilled with refrigerants in connection with leakage and other repairs. This calculation forms the basis for determining the amount of HFC-134a refrigerants refilled in vehicles in Denmark in 2007. Refilled stock = Danish consumption.

The results are shown in the table below.

Table 3.4 Amounts of HFC-134a in mobile A/C systems in 2007

The total stock of HFC-134a in mobile A/C systems in Denmark in 2007 was calculated to be about 228.6 tonnes, which is a further increase compared to 2006 stock. In 2007, the volume of HFC-134a filled onto mobile air conditioning systems was 35.2 tonnes. This volume of refrigerants was used solely for refilling in connection with the maintenance of existing systems /16/. It is indicated from suppliers of mobile A/C refrigerants, that the consumption is even higher than this estimated. One supplier assumes the consumption to be at least approx. 40 tonnes of HFC-134a per year.

3.2.2 Consumption of HFC as foam blowing agent and as propellant

In 2007, the consumption of HFCs in system foam and in other PUR foam and system foam has increased further.

It is considered that the trend in the recent years is a general reduction of the HFC consumption as a blowing agent and this is the direct consequence of a statutory order on phase-out of F-gases, as well as the fact that there are competitive alternative technologies available on the market. As regards production of system foam for production, there is an increase in the recent years in production of system foam for export.

In 2007, the uses of HFCs as propellants in aerosols for specific purposes were about 12 tonnes. This estimate is based on DEPA’s grant of exemptions and production. The consumption seems to be stable tending to a decrease.

As in previous years, there have been no reports of consumption of HFCs for chemical production, fire extinguishing equipment, or other application areas apart from those mentioned.

3.2.3 Consumption of SF₆

The overall consumption of SF₆ in 2007 was approx. 5.4 tonnes. Consumption of SF₆ was used for power switches in high-voltage power systems and laboratories. Consumption of SF₆ in production of double glazed thermal windows has been banned since 1. January 2003.

Table 3.5 Consumption of SF₆ by application area, tonnes

3.2.4 Consumption of PFCs

The consumption of PFCs (per fluoropropane) in 2007 was 0.7 tonnes. The PFC consumption in 2007 derives from to areas:

• optics fibre production
• refrigerants in commercial refrigeration

The optics fibre production used in 2007 PFC-14 (0.1 tonnes) and PFC-318 (0.5 tonnes) for technical purpose.

The consumption of blend refrigerant Isceon 49 contained 0.1 tonnes PFC-14 used for refrigeration in commercial stationary refrigeration systems.

4 Emission of F-gases

• 4.1.1 Emissions of HFCs from refrigerants
• 4.1.2 Emissions of HFCs from PUR foam products and propellants
• 4.1.3 Emissions of sulphur hexafluoride
• 4.1.4 Emissions of per fluorinated hydrocarbons

This section reports the actual emissions of the greenhouse F-gases HFCs, PFCs, and SF₆ for 2007. All emissions are calculated as actual emissions according to IPCC’s tier 2 methodology. The calculation is based on the reports on consumption of these substances analysed by application areas (section 3.2). For relevant product groups, adjustments have been made for imports and exports of the substances in products (see also chapter two for principal description of methodology). The specific emission calculation refers to appendix 4 which shows the particular emission factors, calculation method and assumptions, determination of IPPC Tier method etc., in relation to calculation of emissions from individual substance and application areas /4, 16/.

The GWP-weighted actual emissions of HFCs, PFCs, and SF₆ in 2007 is calculated to 884.4 thousand tonnes CO₂ equivalents. The corresponding emissions were approx. 865.3 thousand tonnes CO₂ equivalents in 2006, which corresponds to a calculated total increase of approx. 19.1 thousand tonnes CO₂ equivalents.

The consumption and GWP contribution for HFCs, PFCs, and SF₆ for 2006 and 2007 are shown in the table below.

Table 4.1 Consumption and GWP contribution by substance group, tonnes

The HFC emission from commercial refrigerators (HFC-134a, HFC-404a and HFC-407c) increased in 2007 as compared to 2006. The increase is coursed solely by stock emission from the commercial refrigerants.

4.1.1 Emissions of HFCs from refrigerants

As required in the IPCC guidance for calculation of emission of f-gases a distinction is made between:

• Fridges and freezers for household use and retailers etc.
• Commercial refrigeration (in industry and retail) and stationary air conditioning systems
• Mobile air conditioning systems (in cars, trucks, bus, trains etc.)
• Mobile refrigeration systems (in vans and lorries)

Actual emissions from these sources occur in connection with:

- filling of refrigerants (emission is 0.5 percent to 2 per cent of refilled amount depending on application area).

- continual release during the operational lifetime. An assumed average value which account operational leakage including release occurring as a result of accident and damage (depending on application area, the average yearly emission differ from 10 percent to 33 percent).

Release resulting from disposal of items and equipment in the applications is not calculated as a contribution to the total f-gas emissions in Denmark because Danish legislation ensures that management and treatment of refrigerants prevent uncontrolled emissions. Thus, disposal in Denmark is stated as an activity in the calculations where zero emission occurs and this principal statement are used in order to reduce stock (the quantity of substances contained in a product after end life time).

Appendix 3 shows the specific emission factors used in the calculations.

Commercial refrigeration and stationary A/C systems

Commercial refrigeration, used e.g. in retail, supermarket, restaurants etc. or in industry, and stationary A/C systems, also used by retailers and industry, as well in offices, constitute the largest source of emissions. The most commonly used refrigerants in this product group are HFC-134a, HFC-404a and HFC-407c, where HFC-404a stands for the majority of the consumption and emissions in 2007.

In addition, use of the refrigerants HFC-408a, HFC-409a, HFC-410a, and HFC-507c is less common, and HFC-401a and HFC-402a are phased out in Denmark because of the substances contents of ozone depleting substances.

It is not relevant to adjust for imports and exports of HFCs in stationary commercial refrigeration and stationary A/C systems since filling of refrigerants only will take place on site when the units are installed.

Table 4.2 shows the consumption, stock and actual emission for 2007 for the main HFC substances used in Danish commercial refrigeration systems. Emissions for HFCs have been converted to CO₂ equivalents in order to take into account the different GWP values of the substances and emission for 2010, 2015 and 2020 in a future scenario is also shown.

Table 4.2 Consumption, stock and actual emissions and GWP contribution from commercial refrigeration 2007; GWP contribution for 2010, 2015 and 2020, tonnes

Click here to see "Table 4.2 Consumption, stock and actual emissions and GWP contribution from commercial refrigeration 2007; GWP contribution for 2010, 2015 and 2020, tonnes".

The projected future scenario takes into account the effect of a statutory order on phasing-out HFCs etc. and the effect of taxes on F-gases. As the tabel indicate the emissions from commercial refrigeration will continue in several years even there are no installations of new HFC refrigeration systems because of the statutory order which not allow construction of new installations (larger than 10 kg HFC) after 1. January 2007. In the trend analysis, the total emission from this sector is estimated to more than 320 000 tonnes CO₂ equivalents in year 2015. But after then a significant reduction is expected and in year 2020 most HFC refrigeration systems is considered phased out.

Refrigerators/freezers

Actual emissions from refrigerants in refrigerators and freezers are determined on the basis of consumption adjusted for imports and exports of HFCs. The calculation assumes that the refrigerant is removed and treated upon disposal so that no emission occurs (see appendix 3).

When adjusting for imports and exports, the estimates of imports/exports in Environmental Project no. 523 are used /2/. In this case, exports are assumed to comprise 50 percent of the consumption pr. year. The calculation is made on the basis of Statistics Denmark's foreign trade statistics /3/ of average figures of the amount of HFC-134a in a standard fridge/freezer manufactured in 1999. This figure has not been updated

Table 4.3 below shows actual emissions from refrigerators/freezers in 2007, 2010 and 2015.

Table 4.3 Emissions of refrigerants from refrigerators/freezers 2007,2010 and 2015 tonnes

Total emissions of HFC-134a and HFC-404a refrigerants from refrigerators/freezers in 2007 were estimated to 14 909 tonnes CO₂ equivalents. In the future scenario of actual emissions, it is estimated that the total emission in 2010 is 15 200 tonnes CO₂ equivalents coursed by an increasing stock.

Mobile A/C

Emissions from mobile A/C systems are mainly due to leakage and accident damage.

The calculation has been adjusted for imports and re-exports of HFC-134a, which is the only HFC imported in A/C systems in cars, vans and trucks. In Denmark, the consumption of HFC-134a for mobile A/C systems is used solely for refilling. Initial filling is carried out by car manufacturers in the country of production.

The assumptions used in the calculation of emission and stock in mobile A/C systems appear from Table 4.4. The assumptions have been adjusted according to individual statistical categories for types of transport and they represent estimated values based on information from car importers and refrigerator service enterprises /16/.

Table 4.4 Parameters used in the calculation of stock in mobile A/C systems, 2007

Table 4.5 shows a projection of the calculated actual emissions from mobile A/C systems and the parameters associated with the calculation.

Table 4.5 Parameters and calculated actual emissions of HFC-134a from mobile A/C systems in 2007, 2010 and 2015, tonnes

Within the next five years, emission from mobile A/C is assumed to be the application area with the largest emission of HFC-134a in Denmark.

Vans and lorries with transport refrigeration system

There are an estimated 5 500-6 000 refrigerated vans and lorries in Denmark /16/. These require an average filling of about 8 kg, equivalent to approx. 46-49 tonnes refrigerants (HFC-134a, HFC-404a or HCFC-22).

Actual emissions from mobile refrigeration systems in vans and lorries in 2007 are stated in the Table 4.6.

Table 4.6 Calculation parameters and actual emissions of HFC-134a and HFC-404a from vans and lorries with transport refrigeration system for 2007,2010 and 2015 tonnes.

There has been no consumption of HFC-402a for refrigerated vans and lorries since this substance has been banned for use in both new and old installations. But the emission from stock is still about 0.2 tonnes HFC-402a, corresponding to 350 tonnes CO₂ equivalents.

The total actual emissions from mobile refrigeration systems in vans and lorries were approx. 20 583 tonnes CO₂ equivalents in 2007 which is a decrease compared to 2006.

4.1.2 Emissions of HFCs from PUR foam products and propellants

Tree calculation principles have been applied in the calculation of emissions of HFCs used in Polyurethan (PUR) foam plastic products, depending on the type of product:

1. Hard PUR foam plastics (closed cell)
2. Soft PUR foam plastics (open cell)
3. Polyether foam (closed cell)

The calculation principles are summerized in table 4.7 below and in appendix four.

Table 4.7 Emission factors in the calculation of emissions from foam plastic products

Insulation foam

There is no longer production of HFC based hard PUR insulation foam in Denmark. This production has been banned in statutory order since 1. January 2006.

The import of HFC-134a in products with PUR insulation foam, e.g. household fridges and freezers, is considered to 0 in 2007. This assumption is difficult to verify and no applicable method seems available.

The calculation of actual emissions are therefore only from existing stock of household fridges and freezers.

Actual emissions of HFC-134a from insulating foam are summarised in Table 4.8.

Table 4.8 Calculation parameters and emissions of HFC-134a from insulating foam for 2007, 2010 and 2015, tonnes

In the projection scenario for 2010 and 2015, it is estimated that the stock will be reduced significantly in 2015 as a result of the phase-out of HFC-134a as blowing agent and from 2018 it is estimated that there will be no more actual emissions from this source.

Soft foam/aerosol sprays

Emissions of HFCs from soft foam (open cell foam) is estimated as 100 per cent of the consumption in the year of application /4/. Emissions from soft foam occur during production and it is therefore not relevant to adjust for imports/exports.

The emission of HFC as a propellant in aerosol sprays is as for soft foam equal to the consumption of HFC-based aerosol sprays, after calculation of imports and exports.

Total emissions from these two areas amount in 2007 to 12.5 tonnes of HFC-134a and 11.6 tonnes of HFC-152a, corresponding to 11 302 tonnes CO₂ equivalents. Compared with 2006, emission estimates have decreased by approx. 8 700 tonnes CO₂ equivalents because of a significant reduction in use of HFC-134a in soft foam blowing but also due to a reduction in emissions from aerosols.

Medical products

The emissions from medical products are judged as marginal and have not been calculated.

Optical fibre production

Optical fibre production constitutes a new sector for F-gas emissions. Both HFC and PFC are used for technical purposes in Danish optics fibre production.

HFC-23 is used as a protection and cleaning gas in the production process. The emission factor is therefore determined as 100 per cent release during production. The actual emission from HFC-23 is 2 800 tonnes CO₂ equivalents in 2007. This sector will probably continue increasing during the coming years.

4.1.3 Emissions of sulphur hexafluoride

The total emission of SF₆ in 2007 has been calculated to 1.3 tonnes, equivalent to a GWP contribution of 30 347 tonnes CO₂ equivalents.

Emissions derive from three sources - power switches, double-glazed windows and laboratories.

Double-glazed windows   

Use of SF₆ in double-glazed windows was phased out in 2002, however, there are still emissions from stock in existing double-glazed windows in Danish buildings. The stock is estimated from consumption data from Danish producers of double-glazed windows 1992-2002 and life time for double-glazed windows are determined to 20 years.

Emissions from double glazed windows are calculated on following factors:

• 15 per cent emission from production
• 1 per cent gradual emission from stock pr. year
• 65 per cent emission when disposal after 20 years

Table 4.9 Calculation parameters and emissions of SF₆ from double-glazed windows for 2007, 2010 and 2015, tonnes

SF₆ emissions from existing double-glazed windows will increase in the coming years because of end of life and disposal of old windows containing SF₆. The future scenario for GWP contribution from double-glazed windows in 2015 shows an increase to 94.5 ktonnes CO₂ equivalents to be compared with 9.1 ktonnes CO₂ equivalents in 2007.

Power switches in high-voltage transmission stations

Power switches are filled or refilled with SF₆, either for new installation or during service and repair. Filling is usually carried out on new installations and a smaller proportion of the consumption of SF₆ is due to refilling /11/.

Emissions from power switches in high-voltage transmission systems are calculated due to the processes involved in the following way:

• release of 5 per cent on filling with new gas (average figure covering normal operation and failure/accidents)
• gradual release of 0.5 per cent from the stock (average figure covering normal operation and failure/accidents)
• release of 5 per cent from drawing off and recycling used gas (average figure covering normal operation and failure/accidents)

These figures are determined in a report of Danish SF₆ use in high-voltage power switches /11/.

No emissions are assumed to result from disposal since the used SF₆ is drawn off from the power switches and is either re-used internally by the company concerned, or re-used externally through means of a collection scheme. Emissions resulting from external re-use are determined on the assumption that 0.5 per cent of the annual stock is sent for external re-use.

Table 4.10 shows the amounts involved in the processes leading to emissions and calculated actual emissions from SF₆ power switches.

Table 4.10 Calculation parameters and emissions of SF₆ from power switches in high-voltage plants 2007, 2010, and 2015, tonnes

Laboratory purposes

Consumption of SF₆ in laboratories covers two purposes:

• Plasma erosion in connection with the manufacture of microchips in clean-room laboratories
• Analysis purposes to a limited extend.

The emission is calculated to 0.3 tonnes SF₆ in 2007 and it was primary for plasma erosion purpose. The emission is 100% release during consumption and equivilizes 6 214 tonnes CO₂ equivalents.

4.1.4 Emissions of per fluorinated hydrocarbons

Commercial refrigerators

The PFC emissions from commercial refrigerators occur from stock and from a smaller use of PFC-14 (R413a which contain 9% perfluorinated hydrocarbons). The actual GWP-weighted emission from this source is 10 537 tonnes CO₂ equivalents, which is a further reduction compared to the last four years.

Stock in commercial refrigerators has been estimated at about 12.9 tonnes in 2007 and trend is going toward phasing out units using HFC blends with PFC refrigerants.

The emission calculations use the same parameters as described for HFC emissions from commercial refrigerators (see appendix 3). Refrigerants containing PFC are only used in stationary refrigerators. Therefore no estimates for imports and exports are relevant.

Table 4.11 Calculation parameters and emissions of PFCs from commercial refrigerators in 2007, 2010 and 2015, tonnes

Optical fibre production

The PFC emission from optics fibre production has increased in 2007. This sector use PFC-14 and PFC-318 for technical purpose in optics fibre production.

The PFCs are used as a protection and cleaning gas in the production process. The emission factor is therefore determined as 100 per cent release during production. The actual emission from PFC-14 and PFC-318 is estimated to 4 825 tonnes CO₂ equivalents in 2007 and it is assumed that this sector will increase during the coming years.

5 List of references

/1/ Arbejdsrapport nr. 20. Forbrug og emissioner af 8 fluorerede og klorerede kulbrinter (working report no. 20 on consumption and emissions of 8 fluorinated and chlorinated hydrocarbons - only available in Danish), Danish EPA, 1996.

/2/ Miljøprojekt nr. 523. Ozonlagsnedbrydende stoffer og visse drivhusgasser - 1998 (environmental project no. 523 on ozone-depleting substances and certain greenhouse gases - 1998 - only available in Danish), Danish EPA, 2000.

/3/ Udenrigshandelen fordelt på varer og land. Januar-december 1989, 1990-1999 (foreign trade analysed by goods and countries. January-December 1989, 1990-1999 - only available in Danish), Statistics Denmark 1989, 1990-1999.

/4/ IPCC, 1997: Revised 1996 IPCC Guidelines for National Greenhouse Gas

Inventories. Available at http://www.ipccnggip.iges.or.jp/public/gl/i-nvs6.htm (15-04-2007).

/5/ Ozonlaget og drivhuseffekten (the ozone layer and the greenhouse effect - only available in Danish), Danish EPA, April 1996.

/6/ Beskyttelse af ozonlaget - nordisk perspektiv (protecting the ozone layer - a Nordic perspective - not available in English), The Nordic Council of Ministers, October, 1997.

/7/ DEFU Komiterapport 94. Håndtering af SF₆ og dets reaktionsprodukter i elforsyningsanlæg (committee report no. 94 from DEFU (Research Institute for Danish Electric Utilities) about management of SF6 and its reaction products in electricity supply plants).

/8/ Methods used to Estimate Emission Inventories of Hydrofluorocarbons, Perfluorocarbons and Sulphur Hexafluoride. Draft report prepared for the UNFCCC secretariat. March Consulting, May 1999.

/9/ Hvor kommer luftforureningen fra? - fakta om kilder, stoffer og udvikling (where does air pollution come from? - facts about sources, substances and development - only available in Danish). Thematic report from NERI, 29/1999.

/10/ Substitutes for Potent Greenhouse Gases - 1998 Final Report (HFCs, PFCs and SF₆), Per Henrik Pedersen, Danish EPA 1998.

/11/ Indsamling og genanvendelse af SF 6 fra højspændingsanlæg (collection and reuse of SF₆ from high-voltage plants - only available in Danish). Tomas Sander Poulsen et al., Danish EPA 2000.

/12/ Denmark’s National Inventory Report - Submitted under the UN Convention on Climate Change. Illerup, J.B., Lyck, E., Winther, M. Rasmussen, E. NERI, 2000. Research Notes No. 127 (http://arbejdsrapporter.dmu.dk).

/13/ Environmental Project No. 1168 2007: Ozone depleting substances and the greenhouse gases HFCs, PFCs and SF₆ - 2005, Danish EPA, 2007.

/14/ Denmark’s National Inventory Report. Submitted under the UN Framework Convention on Climate Change 1990-1999. Emissions Inventories. Department of Policy Analysis. Illerup, Lyck, Winther, 2002. 675 pp Research Notes from NERI 149. (http://www.dmu.dk/1_viden/2_publikationer/3_arbrapporter/rapporter/AR149.pdf).

/15/ Annual Danish Atmospheric Emissions Inventory. 1999. Illerup, Andersen, Winther, Lyck, Bruun. NERI, Denmark.

/16/ Revurdering af emissionsfaktorer for kommercielle køleanlæg og mobile A/C og køleanlæg (re-evaluation of emissions from commercial refrigerators, mobile A/C systems and refrigerators - only available in Danish). Poulsen, T.S, COWI; Environmental report no. 766, Danish EPA, 2002.

/17/ D.A.F prepares statistics of registered vehicles, analysed into various categories of vehicle. These statistics are updated annually and used to calculate Danish filling of HFC-134a in vehicles.

/18/ Denmark's National Inventory Report. Submitted under the United Nations Framework Convention on Climate Change 1990-2001. Emissions Inventories. Department of Policy Analyses. Illerup, Lyck, Nielsen, Winter, Mikkelsen, 2003. Research Notes from NERI no. 181. http://www.dmu.dk/1_viden/2_Publikationer/3_ arbrapporter/rapporter/AR181.pdf

/19/ Denmark’s National Inventory Report. Submitted under the United Nations Framework Convention on Climate Change 1990-2002. Emissions Inventories. National Environmental Research Institute, Denmark. Illerup, Lyck, Nielsen, Winter, Mikkelsen, Hoffmann, Sørensen, Vesterdahl, Fauser. 2004. Research Notes from NERI no. 196.
http://www.dmu.dk/1_viden/2_Publikationer/3_ arbrapporter/rapporter/AR196.pdf

/20/ Anvendelse og håndtering af SF₆-gas i højspændingsanlæg over 100kV (use and management of SF₆ in 100kV or more high-voltage plant). ELTRA Memo elt2004-47a of 18 March 2004.

/21/ Denmark's National Inventory Report 2005. Submitted under the United Nations Framework Convention on Climate Change. 1990-2003. Danmarks Miljøundersøgelser. Illerup, J.B., Lyck, E., Nielsen, M., Winther, M., Mikkelsen, M.H., Hoffmann, L., Sørensen, P.B., Fauser, P. , Thomsen, M., & Vesterdal, L. (2005): - Research Notes from NERI 211: 416 pp. (electronic).
http://www2.dmu.dk/1_viden/2_Publikationer/3_arbrapporter/rapporter/AR211.pdf

/22/ Good Practice Guidance. IPCC Switzerland, 2000.

/23/ Denmark's National Inventory Report 2006. Submitted under the United Nations Framework Convention on Climate Change. 1990-2004. Danmarks Miljøundersøgelser. Illerup, J.B., Lyck, E., Nielsen, M., Winther, M., Mikkelsen, M.H., Hoffmann, L., Sørensen, P.B., Fauser, P. , Thomsen, M., & Vesterdal, L. (2005): - Research Notes from NERI 211: 416 pp. (electronic). http://www2.dmu.dk/1_viden/2_Publikationer/3_fagrapporter/rapporter/FR589.pdf

/24/ Denmark's National Inventory Report 2007. Submitted under the United Nations Framework Convention on Climate Change. 1990-2005. National Environmental Research Institute, University of Aarhus. Illerup, J.B., Lyck, E., Nielsen, O.K., Mikkelsen, M.H., Hoffmann, L., Gyldenkærne, S., Nielsen, M., Winther, M., Fauser, P., Thomsen, M., Sørensen, P.B. & Vesterdal, L. (2007): - NERI Technical Report 632: 642 pp. (electronic). http://www2.dmu.dk/Pub/FR632_Final.pdf

/25/ Environmental Project No. 1234 2008: Ozone depleting substances and the greenhouse gases HFCs, PFCs and SF₆ , 2006, Danish EPA, 2008.

/26/ Denmark’s National Inventory Report 2008. - Emission Inventories 1990-2006 - Submitted under the United Nations Framework Convention on Climate Change. National Environmental Research Institute, University of Aarhus. Nielsen, O.-K., Lyck, E., Mikkelsen, M.H., Hoffmann, L., Gyldenkærne, S., Winther, M., Nielsen, M., Fauser, P., Thomsen, M., Plejdrup, M.S., Illerup, J.B., Sørensen, P.B. & Vesterdal, L. (2008). NERI Technical Report no. 667. 701 pp

APPENDICES

1. GWP values for F-gases

Table 1.a F-gases relevant for Denmark, their chemical formulas and Global Warming Potential (GWP) values used for reporting to the UN Climate Convention and the Kyoto Protocol

1. Mixture consisting of 52 % HFC-143a, 44 % HFC-125 and 4 % HFC-134a.
2. Mixture consisting of 53 % HCFC-22, 13 % HFC-152a and 34 % HCFC-124.
3. Mixture consisting of 38 % HCFC-22, 60 % HFC-125 and 2 % propane
4. Mixture consisting of 25 % HFC-125, 52 % HFC-134a, and 23 % HFC-32.
5. Mixture consisting of 46 % HFC-143a and 7 % HFC-125.
6. A HCFC mixture consisting entirely of HCFCs, where the GWP - in accordance with the climate convention guidelines - is 0, since the mixture does not contain greenhouse gases. The real GWP value is 1,440.
7. Mixture consisting of 50 % HFC-32 and 50 % HFC-125
8. Mixture consisting of 50 % HFC-125, 50 % HFC-143a.
   

2. GWP contribution from HFCs, PFCs, and SF₆, 1993-2020.

The table below shows the time series 1993-2007 and the 2008-2020 projections of F-gases as GWP contributions.

The emission projections are determined by starting with a ‘steady state’ consumption using 2007 as the reference year and the cut-off dates for the phasing-out of specific substances, cf. the Statutory Order regulating certain industrial greenhouse gases.

The calculated GWP contribution expresses actual emissions, adjusted for imports and exports (the latest basis of calculation).

Table 1. GWP contribution from HFCs, PFCs, and SF₆ in 1 000 tonnes CO₂-equivalent, 1993-2020

3. Specification of methods and assumptions for emission calculation

click here to see Tabel "Specification of methods and assumptions for emission calculation".

4. Good Practice Guidance compliance in DK F-gas calculation 2007

The Danish F-gas emissions are calculated for the historical years up to 2007. The time series of emissions are calculated using Good practice principles and the series goes back to 1993, but are to be considered complete from the year 1995.

Key Source Categories

F-gases are determined as a key source category. The contribution of F-gases to national greenhouse gas emission is approx. 1.3 % of total emission excl LULUCF in the most recent historical years of the inventories.

Future trend scenarios

A trend scenario is elaborated until 2020. The scenario is bases on a “steady state” trend but with an inclusion of dates for out phase of determined substances as stated in legal acts.

Methodology

In the following the relevant decision trees from the GPG (Good Practice Guidance) chapter 3 are investigated with respect to the Danish F-gas calculations compliance with GPG.

For the Danish calculation of F-gases it is basically a Tier 2 bottom up approach which is used, while data is reported from identified importers and users of F-gasses in DK. As for verification using import/export data a Tier 2 top down approach is applied. In an annex 4 to the F-gas emission report 2006 (Environmental Protection Agency), there is a specification of the applied approach for each sub source category.

Emission factors

Consumption data of F-gases are provided by suppliers and/or producers. Emission factors are primarily defaults from GPG which are assessed to be applicable in a national context.

In case of commercial refrigerants and Mobile Air Condition (MAC), national emission factors are defined and used. In case of PUR foam blowing of shoe and use of system foam EF are stated by the producer. Because of the relative low consumption from PUR foam blowing of shoes and system foam a certain uncertainty is assessed as acceptable.

Import/export data

Import/export data for sub category sources where import/export are relevant (MAC, fridge/freezers for household) are quantified on estimates from import/export statistic of products + default values of amount of gas in product. The estimates are transparent and described in the annex referred to above.

Import/export data for system foam and commercial refrigerators and stationary air condition are specified in the reporting from importers and users.

Consistency

The time series are consistent as regards methodology. No potential emission estimates are included as emissions in the time series and same emission factors are used for all years.

Reporting and documentation

The national inventories for F-gases are provided on a yearly basis and documented in a yearly report (Environmental Protection Agency, 2004 and 2005).

Detailed data from importers and users and calculations are available and archived in electronic version. The report contains summaries of EF used and information on sources, Further details on methodology and EF are included in annex to the report.

Activity data are described in a spread sheet for the current year. The spread sheet contains the current year as well as the years back. The current version is used with spreadsheet for data for the current year linking to the Danish inventory databases and for the CRF format. In case of changes to the previous reported data this is work out in spreadsheet versions accordingly and reported with explanations as required in the CRF format.

Source specific QA/QC and verification

Comparison of emissions estimates using different approaches

Inventory agencies should use the Tier 1 potential emissions method for a check on the Tier 2 actual emission estimates. Inventory agencies may consider developing accounting models that can reconcile potential and actual emissions estimates and may improve determination of emission factors over time.

This comparison has been carried out in 1995-1997 and for all three years it shows a difference of approx. factor 3 higher emissions by using potential emission estimates.

Inventory agencies should compare bottom-up estimates with the top-down Tier 2 approach, since bottom-up emission factors have the highest associated uncertainty. This technique will also minimise the possibility that certain end-uses are not accounted for in the bottom-up approach.

This exercise has been partly conducted since data from importers (top down) are assessed against data from users (bottom up) to ensure, that import and consumption are more or less equal. The consumption reported from users are always adjusted to the import of substances, which are the most exact data we have.

The uncertainty due to this is, if not all importers are identified because new imported are introduced to the DK market.

National activity data check

For the Tier 2a (bottom-up) method, inventory agencies should evaluate the QA/QC procedures associated with estimating equipment and product inventories to ensure that they meet the general procedures outlined in the QA/QC plan and that representative sampling procedures were used.

No QA/QC plan specifically for the F-gas calculation is developed. However, QC procedures were carried out as described below.

The spread sheets containing activity data has incorporated several data-control mechanisms, which ensure, that data estimates do not contain calculation failures.  A very comprehensive QC procedure on the data in the model for the whole time-series has for this submission been carried out in connection to the process which provided (1) data for the CRF background Tables 2(II).F. for the years (1993)-2002 and (2) provided data for potential emissions in CRF Tables 2(I). This procedure consisted of a check of the input data for the model for each substance. As regards the HFCs this checking was done according to their trade names. Conversion was made to the HFCs substances used in the CRF tables etc. A QC was that emission of the substances could be calculated and checked comparing results from the substances as trade names and as the "no-mixture" substances used in the CRF.

Emission factors check

Emission factors used for the Tier 2a (bottom-up) method should be based on country-specific studies. Inventory agencies should compare these factors with the default values. They should determine if the country-specific values are reasonable, given similarities or differences between the national source category and the source represented by the defaults. Any differences between country specific factors and default factors should be explained and documented.

Country specific emission factors are explained and documented for MAC and commercial refrigerants and SF6 in electric equipment. Separate studies has been carried out and reported. For other sub source categories, the country specific emission factor is assessed to by the same as the IPCC default emission factors.

Emission check

Since the F-gas inventory is developed and made available in full in spread sheets, where HFCs data are for trade names, special procedures are performed to check the full possible correctness of the transformation to the CRF-format through Acces databases.

Uncertainties

In general uncertainty in inventories will arise through at least three different processes:

1. Uncertainties from definitions (e.g. meaning incomplete, unclear, or faulty definition of an emission or uptake);
2. Uncertainties from natural variability of the process that produces an emission or uptake;
3. Uncertainties resulting from the assessment of the process or quantity, including, depending on the method used,: (i) uncertainties from measuring; (ii) uncertainties from sampling; (iii) uncertainties from reference data that may be incompletely described; and (iv) uncertainties from expert judgement.

Uncertainties due to poor definitions are not expected as an issue in the F-gas inventory. The definitions of chemicals, the factors, sub source categories in industries etc. are well defined.

Uncertainties from natural variability are probably occurring in a short term time period, while estimating emissions in individual years. But in a long time period – 10-15 years, these variabilities levels out in the total emission , because input data (consumption of F-gases) are known and are valid data and has no natural variability due to the chemicals stabile nature.

Uncertainties that arise due to imperfect measurement and assessment are probably an issue for:

emission from MAC (HFC-134a)
emission from commercial refrigerants (HFC-134a)
lead to inexact values of the specific consumption of F-gases.

The uncertainty varies from substance to substance. Uncertainty is greatest for HFC-134a due to a widespread application in products that are imported and exported. The greatest uncertainty in the areas of application is expected to arise from consumption of HFC-404a and HFC-134a in commercial refrigerators and mobile refrigerators. The uncertainty on year to year data is influenced by the uncertainty on the rates at which the substances are released. This results in significant differences in the emission determinations in the short term (approx. five years), differences that balances in the long term.

I connection to the work on the Danish National Inventory report general uncertainty estimates for F-gases has been worked out to make the uncertainties for the Danish inventories complete. Refer this report given in the reference list in the main report

Further improvement of uncertainty analysis with respect to the calculation of F-gas emissions are to be considered in future calculations.

References.

Danish Environmental Protection Agency (2004). Ozone depleting substances and the greenhouse gases HFCs, PFCs and SF6. Danish consumption and emissions 2002. Environmental Project No. 890. http://www.mst.dk/udgiv/publikationer/2004/87-7614-099-7/pdf/87-7614-100-4.pdf

Danish Environmental Protection Agency (2005). Ozone depleting substances and the greenhouse gases HFCs, PFCs and SF6. Danish consumption and emissions 2003. Under publication in English. In Danish: Ozonlagsnedbrydende stoffer og drivhusgasserne HFC'er, PFC'er og SF6. Forbrug og emissioner 2003. Miljøprojekt 987. http://www.mst.dk/udgiv/publikationer/2005/87-7614-546-8/pdf/87-7614-547-6.pdf

| Top | | Front page |

Version 1.0 May 2009, © Danish Environmental Protection Agency