A1

Annexes

List of Tables

List of Figures

Figure	Title	Annex	Section

A6.1	UK emissions of direct Greenhouse Gases from IPCC sector 1 1990-2006	Annex 6	A6.1.7
A6.2	UK emissions of indirect Greenhouse Gases from IPCC sector 1 1990-2006	Annex 6	A6.1.7
A6.3	UK emissions of direct Greenhouse Gases from IPCC sector 2 1990-2006	Annex 6	A6.2.10
A6.4	UK emissions of indirect Greenhouse Gases from IPCC sector 2 1990-2006	Annex 6	A6.2.10
A6.5	UK emissions of NMVOC from IPCC sector 3 1990-2006	Annex 6	A6.3
A6.6	UK emissions of direct Greenhouse Gases from IPCC sector 4 1990-2006	Annex 6	A6.4.5
A6.7	UK emissions of indirect Greenhouse Gases from IPCC sector 4 1990-2006	Annex 6	A6.4.5
A6.8	UK emissions and removals of direct Greenhouse Gases from IPCC sector 5 1990-2006	Annex 6	A6.5.5
A6.9	UK emissions of indirect Greenhouse Gases from IPCC sector 5 1990-2006	Annex 6	A6.5.5
A6.10	UK emissions of direct Greenhouse Gases from IPCC sector 6 1990-2006	Annex 6	A6.6.7
A6.11	UK emissions of indirect Greenhouse Gases from IPCC sector 6 1990-2006	Annex 6	A6.6.7
A8.1	Verification of the UK emission inventory estimates for nitrous oxide in Gg yr^-1 for 1995-2006	Annex 8	A8.3
A10.1	Spatial units used for reporting Kyoto protocol LULUCF activities: (left) the four countries of the UK, (right) 20 x 20km grid cells covering the UK	Annex 10	A10.2.3
A11.1	Extremely simplified fuel flows for a final user calculation.	Annex 11	A11.5
A11.2	Fuel use in the example calculation	Annex 11	A11.6
A11.3	Comparison of `direct' and final user emissions of sulphur dioxide according the sectors considered in the final user example	Annex 11	A11.6

ANNEX 1: Key Categories

Key Category Analysis

Up to and including the 2007 NIR this Annex referred to key sources. The NIR now refers to key categories, or key source categories, rather than key sources. “Key categories” is the terminology used in the IPCC's Good Practice Guidance (2000) and the word category is used, rather than source, to avoid any potential confusion with sources and corresponding sinks of carbon.

In the UK inventory, certain source categories are particularly significant in terms of their contribution to the overall uncertainty of the inventory. These key source categories have been identified so that the resources available for inventory preparation may be prioritised, and the best possible estimates prepared for the most significant source categories. We have used the method set out in Section 7.2 of the IPCC Good Practice Guidance (2000) (Determining national key source categories) to determine the key source categories.

The results of the key source category analysis with and without LULUCF, for the base year and the latest reported year, are summarised by sector and gas in Table A1.1.11 to Table A1.1.14. A trend cannot be calculated for the base year alone, and so Table A1.1.11 and Table A1.1.12 only contain key source categories identified by level.

The key category analysis is based on the level analysis and trend analysis which are part of the Approach 1 uncertainty analysis. The Approach 1 uncertainty analysis is an error propagation approach, as described in Section 3.2.3.1 of the IPCC 2006 Guidelines. This analysis has been performed using the data shown in Tables A7.6.1 to A7.6.4 using the same categorisation and the same estimates of uncertainty. The table indicates whether a key category arises from the level assessment or the trend assessment. The factors that make a source a key category are:

A high contribution to the total;
A high contribution to the trend; and
High uncertainty.

For example, transport fuel (1A3b) is a key category for carbon dioxide because it is large; landfill methane (6A) is key because it is large, has a high uncertainty and shows a significant trend.

Both the level and the trend assessments have been completed, following the procedure set out in the IPCC Good Practice Guidance (2000). A qualitative assessment was not conducted, but we do not anticipate that additional source categories would have been identified using such an assessment. The emission estimates were taken from the current inventory.

The results of the level assessment with and without LULUCF the base year, 1990, and the latest reported year are shown in Table A1.1.1 to Table A1.1.6.

The key source categories are highlighted by the shaded cells in the table. The source categories (i.e. rows of the table) were sorted in descending order of magnitude based on the results of the “Level Parameter”, and then the cumulative total was included in the final column of the table. The key source categories are those whose contributions add up to 95% of the total uncertainty in the final column after this sorting process.

The results of the trend assessment with and without LULUCF the base year, 1990 and the latest reported year are shown in Table A1.1.7 and Table A1.1.10. The key source categories are highlighted by the shaded cells in the table. The trend parameter was calculated using absolute value of the result; an absolute function is used since Land Use, Land Use Change and Forestry contains negative sources (sinks) and the absolute function is necessary to produce positive uncertainty contributions for these sinks. The source categories (i.e. rows of the table) were sorted in descending order of magnitude based on the results of the trend parameter, and then the cumulative total was included in the final column of the table. The key source categories are those whose contributions add up to 95% of the total uncertainty in the final column after this sorting process.

The emissions of nitric and adipic acid are both key categories in the UK inventory and the emissions from nitric acid production are associated with a very high uncertainty. The uncertainties assigned to the AD and EFs are: 2B2 Nitric acid production, AD 10%, EF 230%; 2B3 Adipic acid production, AD 0.5%, EF 15%. The uncertainty associated with N₂O emissions released from nitric acid production dominate the overall uncertainty of N₂O emissions in sector 2B. The uncertainty assigned to the EF of nitric acid production was taken from a study commissioned by UK Defra (Salway et al., 1998). The uncertainty in the emission factor from nitric acid production was estimated from a range of values in the available literature - the reference in the report indicates the main source was the 1996 IPCC guidelines. The UK has not reviewed the uncertainties associated with nitric and adipic acid for some time. A review of the uncertainties was planned with the manufacturers during the compilation of the 2009 NIR but this has been deferred until the 2010 NIR.

Any improvements methodological improvements to the uncertainty analysis are discussed in Annex 7.

Table A 1.1.1: Key Category Analysis for the base year based on level of emissions (including LULCUF)

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Table A 1.1.2: Key Category Analysis for the base year based on level of emissions (excluding LULCUF)

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Table A 1.1.3: Key Category Analysis for 1990 based on level of emissions (including LULCUF)

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Table A 1.1.4: Key Category Analysis for 1990 based on level of emissions (excluding LULCUF)

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Table A 1.1.5: Key Category Analysis for the latest reported year based on level of emissions (including LULCUF)

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Table A 1.1.6: Key Category Analysis for the latest reported year based on level of emissions (excluding LULCUF)

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Table A 1.1.7: Key Category Analysis based on trend in emissions (from base year to latest reported year, including LULCUF)

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Table A 1.1.8: Key Category Analysis based on the trend in emissions (from base year to latest reported year, excluding LULCUF)

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Table A 1.1.9: Key Category Analysis based on trend in emissions (from 1990 to latest reported year, including LULCUF)

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Table A 1.1.10: Key Category Analysis based on trend in emissions (from 1990 to latest reported year, excluding LULCUF)

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Table A 1.1.11: Key Source Category Analysis summary for the base year (including LULUCF)

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Table A 1.1.12: Key Source Category Analysis summary for the base year (excluding LULUCF)

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Table A 1.1.13: Key Source Category Analysis summary for the latest reported year (including LULUCF)

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Table A 1.1.14: Key Source Category Analysis summary for the latest reported year (excluding LULUCF)

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ANNEX 2: Detailed Discussion of Methodology and Data for Estimating CO₂ Emissions from Fossil Fuel Combustion

Methodology for estimating CO₂ emissions from fossil fuel combustion is discussed together with the methodologies for other emissions in Annex 3. This is because the underlying methodology for such estimates applies to a range of pollutants and not just CO₂.

ANNEX 3: Other Detailed Methodological Descriptions

This Annex contains background information about methods used to estimate emissions in the UK GHG inventory. This information has not been incorporated in the main body of the report because of the level of detail, and because the methods used to estimate emissions cut across sectors.

This Annex provides:

Background information on the fuels used in the UK GHG inventory.
Mapping between IPCC and NAEI source categories.

Detailed description of methods used to estimate GHG emissions, and emission factors used in those methods - presented in Section A3.3 onwards.

FUELS DATA

The fuels data are taken from DUKES - the Digest of UK Energy Statistics (BERR, 2008), so the fuel definitions and the source categories used in the NAEI reflect those in DUKES. Categories used in the inventory for non-combustion sources generally reflect the availability of data on emissions from these sources.

IPCC Guidelines (IPCC, 1997a) lists fuels that should be considered when reporting emissions. Table A3.1.1 lists the fuels that are used in the GHGI and indicates how they relate to the fuels reported in the NAEI. In most cases the mapping is obvious but there are a few cases where some explanation is required.

Aviation Fuels

UK energy statistics report consumption of aviation turbine fuel and this is mapped onto jet kerosene in the GHGI. Aviation turbine fuel includes fuel that is described as jet gasoline using IPCC terminology.

Coal

The IPCC Guidelines (IPCC, 1997a) classify coal as anthracite, coking coal, other bituminous coal and sub-bituminous coal. In mapping the UK fuel statistics to these categories it is assumed that only the coal used in coke ovens is coking coal; and the rest is reported as either coal or anthracite. Most coal used in the UK is bituminous coal; anthracite is reported separately in UK energy statistics.

Coke Oven Coke

Gas works coke is no longer manufactured in the UK so all coke and coke breeze consumption is reported as coke oven coke.

Colliery Methane

The IPCC Guidelines do not refer to colliery methane but significant use is made of it as a fuel in the UK so emissions are included in the GHGI.

Orimulsion

Orimulsion® is an emulsion of bitumen and water and was burnt in some power stations in the UK, however its use has now been discontinued

Slurry

This is a slurry of coal and water used in some power stations.

Sour Gas

Unrefined natural gas is used as a fuel on offshore platforms and in some power stations. It has a higher carbon and sulphur content than mains gas.

Wastes used as fuel

The following wastes are used for power generation: municipal solid waste, scrap tyres, poultry litter, meat and bone meal, landfill gas, sewage gas, and waste oils. Some waste oils and scrap tyres are burnt in cement kilns. Further waste oils are burnt by other industrial sectors, and it is assumed that some lubricants consumed in the UK are destroyed (burnt) in engines.

Table A 3.1.1: Mapping of fuels used in the GHGI and the NAEI

	GHGI	NAEI
Category	Subcategory	Subcategory
Liquid	Motor Gasoline Aviation Gasoline Jet Kerosene Other Kerosene Gas/Diesel Oil Residual Fuel Oil Orimulsion Liquefied Petroleum Gas Naphtha Petroleum Coke Refinery Gas Other Oil: Other Other Oil: Other Lubricants	Petrol Aviation Spirit Aviation Turbine Fuel¹ (ATF) Burning Oil Gas Oil/ DERV Fuel Oil Orimulsion Liquefied Petroleum Gas (LPG) Naphtha Petroleum Coke Other Petroleum Gas (OPG) Refinery Miscellaneous Waste Oils Lubricants
Solid	Anthracite Coking Coal Coal Coal Coke Oven Coke Patent Fuel Coke Oven Gas Blast Furnace Gas	Anthracite Coal² Coal Slurry³ Coke Solid Smokeless Fuel (SSF) Coke Oven Gas Blast Furnace Gas
Gas	Natural Gas Natural Gas Colliery Methane⁵	Natural Gas Sour Gas⁴ Colliery Methane
Other Fuels	Municipal Solid Waste Industrial Waste: Scrap Tyres	Municipal Solid Waste Scrap Tyres
Biomass	Wood/Wood Waste Other Solid Biomass: Straw Other Solid Biomass: Poultry Litter, Meat & Bone Meal Landfill Gas Sludge Gas	Wood Straw Poultry Litter, Meat & bone meal Landfill Gas Sewage Gas

1 Includes fuel that is correctly termed jet gasoline.

2 Used in coke ovens.

3 Coal-water slurry used in some power stations

4 Unrefined natural gas used on offshore platforms and some power stations

5 Not referred to in IPCC Guidelines (IPCC, 1997a) but included in GHGI.

NAEI Source Categories and IPCC Equivalents

Tables A3.2.1 to A3.2.7 relate the IPCC source categories to the equivalent NAEI base categories. In most cases it is possible to obtain a precise mapping of an NAEI source category to a specific IPCC source category. In some cases the relevant NAEI source category does not correspond exactly to the IPCC source category and in a few cases an equivalent NAEI source category is not estimated or is defined quite differently. As a result, total annual emissions given in the NAEI and GHGI differ slightly. The source categories responsible for the differences between the GHGI and the NAEI are Land Use, Land Use Change and Forestry sources.

Tables A3.2.1 to A3.2.7 refer to NAEI base categories. Normally the NAEI is not reported in such a detailed form but in the summary UNECE/CORINAIR SNAP97, eleven-sector format or the new NFR (Nomenclature For Reporting) system used for submission to CORINAIR.

Table A 3.2.1: Mapping of IPCC Source Categories to NAEI Source Categories - fuel combustion

IPCC Source Category	NAEI Source Category

1A1a Public Electricity and Heat Production	Power Stations
1A1b Petroleum Refining	Refineries (Combustion)
1A1ci Manufacture of Solid Fuels	SSF Production Coke Production
1A1cii Other Energy Industries	Collieries Gas Production Gas Separation Plant (Combustion) Offshore Own Gas Use Production of Nuclear Fuel Town Gas Production
1A2a Iron and Steel	Iron and Steel (Combustion) Iron and Steel (Sinter Plant) Iron and Steel (Blast Furnaces)
1A2b Non-Ferrous Metals 1A2c Chemicals 1A2d Pulp, Paper and Print 1A2e Food Processing, Beverages, Tobacco	Included under Other Industry (Combustion)
1A2fi Other	Other Industry (Combustion) Cement (Fuel Combustion) Cement (Non-decarbonising) Lime Production (Combustion) Autogenerators Ammonia (Combustion)
1A2fii Other (Off-road Vehicles and Other Machinery)	Other Industry Off-road
1A3a Civil Aviation	No comparable category
1A3b Road Transportation	Road Transport
1A3c Railways	Railways (Freight) Railways (Intercity) Railways (Regional)
1A3di International Marine	International Marine
1A3dii Internal Navigation	Coastal Shipping
1A3e Other Transport	Aircraft Support
1A4a Commercial/Institutional	Miscellaneous Public Services Railways (Stationary Sources)
1A4bi Residential	Domestic
1A4bii Residential Off-road	Domestic, House & Garden
1A4ci Agriculture/Forestry/Fishing (Stationary)	Agriculture
1A4cii Agriculture/Forestry/Fishing (Off-road Vehicles and Other Machinery)	Agriculture Power Units
1A4ciii Agriculture/Forestry/Fishing (Fishing)	Fishing
1A5a Other: Stationary	No comparable category-included in 1A4a
1A5b Other: mobile	Aircraft Military Shipping Naval

Table A 3.2.2: Mapping of IPCC Source Categories to NAEI Source Categories (Fugitive emissions from fuels)

IPCC Source Category	NAEI Source Category
1B1a Coal Mining i Mining activities	Deep-Mined Coal
1B1a Coal Mining ii Post mining activities	Coal Storage & Transport
1B1a Coal Mining ii Surface Mines	Open-Cast Coal
1B1b Solid Fuel Transformation	Coke Production (Fugitive) SSF Production (Fugitive) Flaring (Coke Oven Gas)
1B1c Other	Not Estimated
1B2a Oil i Exploration	Offshore Oil and Gas (Well Testing)
1B2a Oil ii Production	Offshore Oil and Gas
1B2a Oil iii Transport	Offshore Loading Onshore Loading
1B2a Oil iv Refining/Storage	Refineries (drainage) Refineries (tankage) Refineries (Process) Oil Terminal Storage Petroleum Processes
1B2a Oil vi Other	Not Estimated
1B2a Oil v Distribution of oil products	Petrol Stations (Petrol Delivery) Petrol Stations (Vehicle Refuelling) Petrol Stations (Storage Tanks) Petrol Stations (Spillages) Petrol Terminals (Storage) Petrol Terminals (Tanker Loading) Refineries (Road/Rail Loading)
1B2b i Natural Gas Production	Gasification Processes
1B2b ii Natural Gas. Transmission/Distribution	Gas Leakage
1B2ciii Venting: Combined	Offshore Oil and Gas (Venting)
1B2ciii Flaring: Combined	Offshore Flaring Refineries (Flares)

Table A 3.2.3: Mapping of IPCC Source Categories to NAEI Source Categories (Industrial Processes)

IPCC Source Category	NAEI Source Category
2A1 Cement Production	Cement (Decarbonising)
2A2 Lime Production	Lime Production (Decarbonising)
2A3 Limestone and Dolomite Use	Glass Production: Limestone and Dolomite Iron and Steel (Blast Furnace): Limestone and Dolomite Power Stations (FGD)
2A4 Soda Ash Production and Use	Glass Production: Soda Ash
2A5 Asphalt Roofing	Not Estimated
2A6 Road Paving with Asphalt	Road Construction
2A7 Other	Brick Manufacture (Fletton) Glass (continuous filament glass fibre) Glass (glass wool)
2B1 Ammonia Production	Ammonia Feedstock
2B2 Nitric Acid Production	Nitric Acid Production
2B3 Adipic Acid Production	Adipic Acid Production
2B4 Carbide Production
2B5 Other	Sulphuric Acid Production Chemical Industry Chemical Industry (Carbon Black) Chemical Industry (Ethylene) Chemical Industry (Methanol) Chemical Industry (Nitric Acid Use) Chemical Industry (Pigment Manufacture) Chemical Industry (Reforming) Chemical Industry (Sulphuric Acid Use) Coal, tar and bitumen processes Solvent and Oil recovery Ship purging
2C1 Iron and Steel	Iron and Steel (other) Iron and Steel (Basic Oxygen Furnace) Iron and Steel (Electric Arc Furnace) Iron and Steel Flaring (Blast Furnace Gas) Rolling Mills (Hot & Cold Rolling)
2C2 Ferroalloys Productions	No Comparable Source Category
2C3 Aluminium Production	Non-Ferrous Metals (Aluminium Production)
2C4 SF6 Used in Aluminium and Magnesium Foundries	SF₆ Cover Gas
2C5 Other	Non-Ferrous Metals (other non-ferrous metals) Non-Ferrous Metals (primary lead/zinc) Non-Ferrous Metals (secondary Copper) Non-Ferrous Metals (secondary lead)
2D1 Pulp and Paper	Wood Products Manufacture
2D2 Food and Drink	Brewing (barley malting, fermentation, wort boiling) Bread Baking Cider Manufacture Other Food (animal feed; cakes, biscuits, cereals; coffee, malting, margarine and other solid fats; meat, fish and poultry; sugar) Spirit Manufacture (barley malting, casking distillation, fermentation, maturation, spent grain drying) Wine Manufacture
2E1 Halocarbon & SF6 By-Product Emissions 2E2 Halocarbon & SF6 Fugitive Emissions	Halocarbons Production (By-Product and Fugitive)
2E3 Halocarbon & SF6 Other	Not Estimated
2F1 Refrigeration & Air Conditioning Equipment	Refrigeration Supermarket Refrigeration Mobile Air Conditioning
2F2 Foam Blowing	Foams
2F3 Fire Extinguishers	Fire Fighting
2F2 Aerosols	Metered Dose Inhalers Aerosols (Halocarbons)
2F5 Solvents	Not Occurring
2F8a One Component Foams
2F8 Semiconductors, Electrical and Production of Trainers	Electronics Training Shoes Electrical Insulation

Table A 3.2.4: Mapping of IPCC Source Categories to NAEI Source Categories

IPCC Source Category	NAEI Source Category
3A Paint Application	Decorative paint (retail decorative) Decorative paint (trade decorative) Industrial Coatings (automotive) Industrial Coatings (agriculture & construction) Industrial Coatings (aircraft) Industrial Coatings (Drum) Industrial Coatings (coil coating) Industrial Coatings (commercial vehicles) Industrial Coatings (high performance) Industrial Coatings (marine) Industrial Coatings (metal and plastic) Industrial Coatings (metal packaging) Industrial Coatings (vehicle refinishing) Industrial Coatings (wood)
3B Degreasing & Dry Cleaning	Dry Cleaning Surface Cleaning Leather Degreasing
3C Chemical Products, Manufacture & Processing	Coating Manufacture (paint) Coating Manufacture (ink) Coating Manufacture (glue) Film Coating Leather coating Other Rubber Products Tyre Manufacture Textile Coating
3D Other	Aerosols (Car care, Cosmetics & toiletries, household products) Agrochemicals Use Industrial Adhesives Paper Coating Printing Other Solvent Use Non Aerosol Products (household, automotive, cosmetics & toiletries, domestic adhesives, paint thinner) Seed Oil Extraction Wood Impregnation

Table A 3.2.5: Mapping of IPCC Source Categories to NAEI Source Categories (Agriculture)

IPCC Source Category	NAEI Source Category
4A1 Enteric Fermentation: Cattle	Dairy Cattle Enteric Other Cattle Enteric
4A2 Enteric Fermentation: Buffalo	Not Occurring
4A3 Enteric Fermentation: Sheep	Sheep Enteric
4A4 Enteric Fermentation: Goats	Goats Enteric
4A5 Enteric Fermentation: Camels & Llamas	Not Occurring
4A6 Enteric Fermentation: Horses	Horses Enteric
4A7 Enteric Fermentation: Mules & Asses	Not Occurring
4A8 Enteric Fermentation: Swine	Pigs Enteric
4A9 Enteric Fermentation: Poultry	Not Occurring
4A10 Enteric Fermentation: Other: Deer	Deer Enteric
4B1 Manure Management: Cattle	Dairy Cattle Wastes Other Cattle Wastes
4B2 Manure Management: Buffalo	Not Occurring
4B3 Manure Management: Sheep	Sheep Wastes
4B4 Manure Management: Goats	Goats Wastes
4B5 Manure Management: Camels & Llamas	Not Occurring
4B6 Manure Management: Horses	Horses Wastes
4B7 Manure Management: Mules & Asses	Not Occurring
4B8 Manure Management: Swine	Pigs Wastes
4B9 Manure Management: Poultry	Broilers Wastes Laying Hens Wastes Other Poultry
4B9a Manure Management: Other: Deer	Deer Wastes
4B10 Anaerobic Lagoons	Not Occurring
4B11 Liquid Systems	Manure Liquid Systems
4B12 Solid Storage and Dry Lot	Manure Solid Storage and Dry Lot
4B13 Other	Manure Other
4C Rice Cultivation	Not Occurring
4D 1 Agricultural Soils: Direct Soil Emissions 4D 2 Agricultural Soils: Animal Emissions 4D 4 Agricultural Soils: Indirect Emissions	Agricultural Soils Fertiliser Agricultural Soils Crops
4E Prescribed Burning of Savannahs	Not Occurring
4F1 Field Burning of Agricultural Residues: Cereals	Barley Residue Wheat Residue Oats Residue
4F5 Field Burning of Agricultural Residues: Other: Linseed	Linseed Residue
4G Other	Not Estimated

Emissions in this NIR are reported used the reporting nomenclature specified in the LULUCF Good Practice Guidance and agreed at the 9^th Conference of Parties for reporting to the UNFCCC. These reporting categories are very different to those previously used, and to the NAEI source categories, which are based on NFR codes. Table A 3.2.6 summarises the categories used, and which NAEI categories they correspond to.

Table A 3.2.6: Mapping of IPCC Source Categories to NAEI Source Categories (Land Use, Land Use Change and Forestry)

IPCC Source Category	NAEI Source Category
5A Forest Land (Biomass Burning - wildfires)	Not Reported
5A Forest Land (Drainage of soils)	Not Reported
5A1 Forest Land Remaining Forest Land	Not Reported
5A2 Forest Land (N fertilisation)	Not Reported
5A2 Land Converted to Forest Land	Not Reported
5B Cropland (Biomass Burning - controlled)	Not Reported
5B Liming	4D1 Liming of Agricultural Soils
5B1 Cropland Remaining Cropland	Not Reported
5B2 Land Converted to Cropland	Not Reported
5C Grassland (Biomass burning - controlled)	Not Reported
5C Liming	4D1 Liming of Agricultural Soils
5C1 Grassland Remaining Grassland	Not Reported
5C2 Land converted to grassland	Not Reported
5D Wetlands (Biomass burning - controlled)	Not Reported
5D1 Wetlands remaining wetlands	Not Reported
5D2 Land converted to wetlands	Not Reported
5E Settlements (Biomass burning - controlled)	Not Reported
5E1 Settlements remaining settlements	Not Reported
5E2 Land converted to settlements	Not Reported
5F Other land (Biomass burning - controlled)	Not Reported
5F1 Other land remaining other land	Not Reported
5F2 Land converted to other land	Not Reported
5G Other (Harvested wood)	Not Reported
No relevant category	5B Deforestation

Table A 3.2.7: Mapping of IPCC Source Categories to NAEI Source Categories (Waste)

IPCC Source Category	NAEI Source Category
6A1 Managed Waste Disposal on Land	Landfill
6A2 Unmanaged Waste Disposal on Land	Not Occurring
6A3 Other	Not Occurring
6B1 Industrial Wastewater 6B2 Domestic and Commercial Wastewater 6B3 Other	Sewage Sludge Disposal
6C Waste Incineration	Incineration: MSW Incineration: Sewage Sludge Incineration: Clinical Incineration: Cremation
6D Other Waste	Not estimated

Energy (CRF sector 1)

The previous two sections defined the fuels and source categories used in the NAEI and the GHGI. This section describes the methodology used to estimate the emissions arising from fuel combustion for energy. These sources correspond to IPCC Table 1A.

There is little continuous monitoring of emissions performed in the UK; hence information is rarely available on actual emissions over a specific period of time from an individual emission source. In any case, emissions of CO₂ from fuel are probably estimated more accurately from fuel consumption data.

The majority of emissions are estimated from other information such as fuel consumption, distance travelled or some other statistical data related to the emissions. Estimates for a particular source sector are calculated by applying an emission factor to an appropriate statistic. This is as follows:

Total Emission = Emission Factor × Activity Statistic

Emission factors are typically derived from measurements on a number of representative sources and the resulting factor applied to the UK environment.

For the indirect gases, emissions data are sometimes available for individual sites from databases such as the Environment Agency's Pollution Inventory (PI). Hence the emission for a particular sector can be calculated as the sum of the emissions from these point sources. That is:

Emission = Σ Point Source Emissions

However it is still necessary to make an estimate of the fuel consumption associated with these point sources, so that the emissions from non-point sources can be estimated from fuel consumption data without double counting. In general the point source approach is only applied to emissions of indirect greenhouse gases for well-defined point sources (e.g. power stations, cement kilns, coke ovens, refineries). Direct greenhouse gas emissions and most non-industrial sources are estimated using emission factors.

Basic Combustion Module

For the pollutants and sources discussed in this section the emission results from the combustion of fuel. The activity statistics used to calculate the emission are fuel consumption statistics taken from BERR (2008). A file of the fuel combustion data used in the inventory is provided on a CD ROM attached to this report. Emissions are calculated according to the following equation:

E(p,s,f) = A(s,f) × e(p,s,f)

where

E(p,s,f) = Emission of pollutant p from source s from fuel f (kg);

A(s,f) = Consumption of fuel f by source s (kg or kJ); and

e(p,s,f) = Emission factor of pollutant p from source s from fuel f (kg/kg or kg/kJ).

The pollutants estimated in this way are as follows:

Carbon dioxide as carbon;

Methane;
Nitrous oxide;
NO_xas nitrogen dioxide (some source/fuel combinations only);
NMVOC;
Carbon monoxide (some source/fuel combinations only); and
Sulphur dioxide (some source/fuel combinations only).

The sources covered by this module are:

Domestic;
Miscellaneous;
Public Service;
Refineries (Combustion);
Iron & Steel (Combustion);
Iron & Steel (Blast Furnaces);
Iron & Steel (Sinter Plant);
Other Industry (Combustion);
Autogenerators;
Gas Production;
Collieries;
Production of Nuclear Fuel;
Coastal Shipping;
Fishing;
Agriculture;
Ammonia (Combustion);
Railways (Stationary Sources);
Aircraft Military; and
Shipping Naval.

The fuels covered are listed in Annex 3, Section 3.1, though not all fuels occur in all sources.

For the estimation of CO and NO_x emissions from industrial, commercial/institutional and domestic sources the methodology allows for source/fuel combinations to be further broken down by a) thermal input of combustion devices; b) type of combustion process e.g. boilers, furnaces, turbines etc. Different emission factors are applied to these subdivisions of the source/fuel combination. Most of these emission factors are taken from literature sources, predominantly from US EPA, (2005), EMEP/CORINAIR (2003), and Walker et al, (1985). Some emissions data reported in the Pollution Inventory (Environment Agency, 2008) are also used to generate emission factors.

Tables A3.3.1 to A3.3.4 list the emission factors used in this module. Emission factors are expressed in terms of kg pollutant/tonne for solid and liquid fuels, and g/TJ gross for gases. This differs from the IPCC approach, which expresses emission factors as tonnes pollutant/TJ based on the net calorific value of the fuel. For gases the NAEI factors are based on the gross calorific value of the fuel. This approach is used because the gas consumption data in BERR (2008) are reported in terms of energy content on a gross basis.

For most of the combustion source categories, the emission is estimated from fuel consumption data reported in DUKES and an emission factor appropriate to the type of combustion e.g. commercial gas fired boiler.

However the DUKES category `Other Industries' covers a range of sources and types, so the Inventory disaggregates this category into a number of sub-categories, namely:

Other Industry;
Other Industry Off-road;
Ammonia Feedstock (natural gas only);
Ammonia (Combustion) (natural gas only);
Cement (Combustion); and
Lime Production (non-decarbonising).

Thus the GHGI category Other Industry refers to stationary combustion in boilers and heaters by industries not covered elsewhere (including the chemicals, food & drink, non-ferrous metal, glass, ceramics & bricks, textiles & engineering sectors). The other categories are estimated by more complex methods discussed in the sections indicated. For certain industrial processes (e.g. Lime production, cement production and ammonia production), the methodology is discussed in Section A3.4 as the estimation of the fuel consumption is closely related to the details of the process. However, for these processes, where emissions arise from fuel combustion for energy production, these are reported under IPCC Table 1A. The fuel consumption of Other Industry is estimated so that the total fuel consumption of these sources is consistent with DUKES (BERR, 2008).

According to IPCC 1996 Revised Guidelines, electricity generation by companies primarily for their own use is autogeneration, and the emissions produced should be reported under the industry concerned. However, most National Energy Statistics (including the UK) report emissions from electricity generation as a separate category. The UK inventory attempts to report as far as possible according to the IPCC methodology. Hence autogenerators would be reported in the relevant sector where they can be identified e.g. iron and steel (combustion), refineries (combustion). In some cases the autogenerator cannot be identified from the energy statistics so it would be classified as other industry (combustion). This means that the split between iron and steel (combustion) and other industry (combustion) may be uncertain. Also, for certain sectors, data on fuel deliveries are used in preference to data on fuel consumption because deliveries will include autogeneration whereas consumption does not.

In 2004, an extensive review of carbon factors in the UK GHG inventory was carried out (Baggott et al., 2004). This review covered over 90% of carbon emissions in the UK and focused on obtaining up-to-date carbon factors and oxidation factors for use in the inventory. The methods used to derive the carbon factors are described below.

In the UK, power stations and the cement industry are important users of coal. Power station emissions account for approximately 85% of UK carbon emissions. The carbon contents of coal used by these two industries are obtained directly from industry representatives and this ensures that the inventory contains emissions of CO₂ that are estimated as accurately as possible. Normally, the carbon contents of power station coal are updated annually.

The cement industry imports most of the coal it uses from abroad, and the coal burnt is considered to be 100% oxidised due to the high operating temperatures of cement kilns.

The carbon contents of fuels used by other industry sectors are not requested annually, but a time series is updated each year by scaling the carbon contents to the GCVs presented in the latest version of the Digest of UK Energy Statistics (BERR, 2008). The carbon content of a fuel is closely correlated with the calorific value and so using calorific values as a proxy provides a good estimate of the changing carbon contents.

The major liquid fuel carbon factors in the inventory have been from the UK Petroleum Institute Association (UKPIA). During the review in 2004, UKPIA undertook fuel analysis and provided carbon emission factors for the following fuels:

Petrol;
Burning oil;
ATF;
Aviation spirit;
Diesel;
Fuel oil;
Gas oil;
Petroleum coke;
Naphtha;
OPG;
Propane; and
Butane.

UKPIA advise whether these factors are still valid each year.

For the cement sector, industry specific petroleum coke carbon factors are used as like coal, the sector uses different types of petroleum coke to other industries.

Natural gas factors are provided by the UK gas network distributors. These data are derived from extensive measurements which are carried out by the various network distributors and data are provided to us each year.

In the 2009 GHGI, carbon factors from the EUETS were introduced for certain sector and fuel combinations. These sectors are listed below, along with the years for which EUETS data was introduced.

Power Stations - coal - for 2005, 2006, 2007
Power Stations - fuel oil - for 2005, 2006, 2007
Power Stations - natural gas - for 2005, (interpolated 2006, 2007)
Autogenerators - coal - 2005, 2006, 2007
Refineries - fuel oil - 2005, (interpolated 2006, 2007)
Refineries - Petroleum coke - 2005, 2006, 2007

For years and sectors not listed, carbon factors remained the same as in previous inventories and as described in the carbon factors review from 2004.

Implied emission factors (IEFs) for carbon are partly driven by the carbon emission factors and so there is some variability across the time series due to changes in UK factors. Updating carbon emission factors each year can cause large inter-annual changes in carbon implied emission factors (IEFs). One approach to avoid this, which has been suggested by an UNFCCC Expert Review Team, is to use regression analysis and derive the CEFs from the best fit line. We have considered this approach and discussed with UK DECC. For the moment, the UK continues to update CEFs on an annual basis because it considers that this approach provides the most accurate estimates of carbon emissions in a given year.

For gas in sector 1A1, the carbon IEFs for gas are high in relation to other Member States of the European Union. This is because sour gas has been used in the UK ESI sector from 1992 onwards, and sour gas has a much greater IEF than natural gas. The increase in the CO₂ IEF between 1991 and 1992 is explained by the commissioning of Peterhead power station in Scotland.

Table A 3.3.1: Emission Factors for the Combustion of Liquid Fuels for 2007¹ (kg/t)

Fuel	Source	C^aj	CH₄	N₂O	NO_x	CO	NMVOC	SO₂
ATF	Aircraft Military	859^a	0.103^ad	0.1^g	8.5^ad	8.2^ad	1.1^ad	10.9^z
Burning Oil	Domestic	859^a	0.462^g	0.0277^g	3.23^l	1.85^l	0.047^f	0.59^z
Burning Oil	Other Industry	859^a	0.0924^g	0.0277^g	3.32^l	0.19^l	0.028^e	0.59^z
Burning Oil	Public Service, Railways (Stationary)	859^a	0.462^g	0.0277^g	2.05^l	0.16^l	0.047^f	0.59^z
Burning Oil	Miscellaneous	859^a	0.462^g	0.0277^g	2.70^l	0.16^l	0.047^f	0.59^z
Gas Oil	Agriculture	870^a	0.455^g	0.0273^g	0^ap	0^ap	0.048^f	2.9^z
Gas Oil	Domestic	870^a	0.455^g	0.0273^g	3.19^l	1.82^l	0.047^f	2.7^z
Gas Oil	Fishing, Coastal Shipping, Naval, International Marine	870^a	0.05^ap	0.08^ap	72.3^aq	7.4^ap	3.5^aq	19.6^ar
Gas Oil	Iron&Steel	870^a	0.0910^g	0.0273^g	20.17^l	7.95^l	0.028^f	2.7^z
Gas Oil	Refineries	870^a	0.136^g	0.0273^g	4.55^k	0.24ⁱ	0.028^f	2.7^z
Gas Oil	Other Industry	870^a	0.0910^g	0.0273^g	5.08^l	0.90^l	0.028^f	2.7^z
Gas Oil	Public Service	870^a	0.455^g	0.0273^g	2.44^l	0.38^l	0.047^f	2.7^z
Gas Oil	Miscellaneous	870^a	0.455^g	0.0273^g	1.34^l	0.17^l	0.047^f	2.7^z
Fuel Oil	Agriculture	879^a	0.433^g	0.026^g	7.69^l	0.31^l	0.14^f	16.8^z
Fuel Oil	Public Service