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3. Emission factors and methods 2006

3.1 Scope 1: Direct emissions

3.1.1 Stationary combustion of fuels

Table 1 contains emission factors for common fuels used for stationary combustion.

These emission factors are sourced from the Energy Greenhouse Gas Emissions 1990–2006 publication. The Energy Greenhouse Gas Emissions publication provides CO2, CH 4 and N2O emission factors for a range of fuels used by the energy sector.

In line with the reporting requirements of ISO 14064–1 and The GHG Protocol emission factors are provided to allow calculation of CO2, CH 4 and N2O separately.

Table 1: Fuel combustion emission factors (fuels used for stationary combustion) – 2006

Emission source

User

Unit

Emission factor
total CO2 -e*
(kg CO2 -e/unit)

Emission factor
CO2 (kg CO2/unit)

Emission factor
CH 4 (kg CO2-e/unit)

Emission factor
N2O (kg CO2 -e/unit)

Distributed natural gas Commercial

kWh

0.190

0.187

0.0000816

0.00231

GJ

52.7

52.07

0.0227

0.642

Coal – bituminous

Commercial

kg

2.58

2.56

0.00588

0.0121

Coal – sub-bituminous

Commercial

kg

2.016

2.0020

0.00447

0.00924

Coal – lignite

Commercial

kg

1.50

1.49

0.00318

0.00658

Coal – default**

Commercial

kg

2.016

2.0020

0.00447

0.00924

Diesel

Commercial

litre

2.61

2.61

0.000529

0.00446

LPG***

Commercial

kg

2.97

2.96

0.00109

0.00875

Heavy fuel oil

Commercial

litre

2.97

2.96

0.00114

0.00360

Light fuel oil

Commercial

litre

2.72

2.72

0.00106

0.00337

Distributed natural gas Industry

kWh

0.188

0.187

0.0000953

0.000100

GJ

52.1

52.07

0.0265

0.0279

Coal – bituminous

Industry

kg

2.58

2.56

0.000411

0.0139

Coal – sub-bituminous

Industry

kg

2.013

2.0020

0.000313

0.0106

Coal – lignite

Industry

kg

1.50

1.49

0.000223

0.00752

Coal – default**

Industry

kg

2.013

2.0020

0.000313

0.0106

Diesel

Industry

litre

2.61

2.61

0.000151

0.00446

LPG***

Industry

kg

2.97

2.96

0.00109

0.00875

Heavy fuel oil

Industry

litre

2.97

2.96

0.00244

0.00360

Light fuel oil

Industry

litre

2.72

2.72

0.000152

0.00449

Wood

Industry

kg

0.0178*****

1.26

0.00361

0.0142

Fireplaces****

kg

0.0865*****

1.26

0.0723

0.0142

* Use the total CO2-e emission factor for calculating total CO2-e emissions, rather than summing the totals for CO2, CH 4 and N2O.

** The default coal emission factor should be used if it is not possible to identify the specific type of coal.

*** Fuel use data in litres can be converted to kilograms by multiplying by the specific gravity of 0.536 kg/l.

**** It is not expected that many commercial or industrial users will burn wood in fireplaces but this emission factor has been provided for completeness. It is the default residential emission factor.

***** The total CO2-e emission factor (for wood) does not include the CO2 emission factor. Under ISO 14064-1 and The GHG Protocol reporting requirements, only CH 4 and N2O emissions from the combustion of biomass are included as Scope 1 emissions. CO2 emissions, from the combustion of biologically sequestered carbon, are reported separately from the scopes.

Assumptions

The kg CO2-e per activity unit emission factors supplied in Table 1, are derived using calorific values sourced from the New Zealand Energy Data File 2007. The calorific values used can be found in Appendix 1.

All emission factors incorporate relevant oxidation factors which are sourced from New Zealand’s Greenhouse Gas Inventory1990–2005. Oxidation factors allow for the small proportion of carbon that remains unoxidised due to incomplete combustion, and remains as soot and ash. The oxidation factors used for each of the fuels can be found in Appendix 1.

The emission factors provided above account for the Scope 1 emissions resulting from fuel combustion. They are not full fuel cycle emission factors and do not incorporate Scope 3 emissions associated with the extraction, production and transport of the fuel.

The distributed natural gas emission factor is a weighted average of Maui- and Kapuni-treated natural gas. The Energy Greenhouse Gas Emissions publication contains additional CO2 emission factors for a number of other gas streams.

The default coal emission factor is assumed to be the same as the sub-bituminous coal emission factor on the basis that the majority of coal use is of sub-bituminous coal.10

The Automotive Gas Oil-50 ppm Sulphur emission factor (provided in the Energy Greenhouse Gas Emissions 1990–2006 publication) has been used as the default emission factor for diesel.

Example calculation

A commercial organisation uses 1,400 kg of LPG to heat one of its office buildings in 2006.

CO2 emissions = 1,400 * 2.96 = 4,144 kg CO2/1000 = 4.14 tonnes CO2

CH 4 emissions = 1,400 * 0.00109 = 1.526 kg CO2-e/1000 = 0.00153 tonnes CO2-e

N2O emissions = 1,400 * 0.00875 = 12.25 kg CO2-e/1000 = 0.0123 tonnes CO2-e

Total CO2-e emissions = 1,400 * 2.97 = 4,158 kg CO2-e/1000 = 4.158 tonnes CO2-e

3.1.2 Transport fuels (where fuel use data is available)

Scope 1 emissions from transport occur from vehicles which are owned or controlled by the reporting organisation. The most accurate way to quantify the emissions associated with transport is using information on the quantity of fuel used.

Emission factors for combustion of transport fuels are reported in Table 2. The emission factors are sourced from the Energy Greenhouse Gas Emissions 1990–2006 publication.

Table 2: Fuel combustion emission factors (transport fuels) – 2006

Fuel

Unit

Emission factor
Total CO2 -e*
(kg CO2 -e/unit)

Emission factor
CO2
(kg CO2 /unit)

Emission factor
CH 4
(kg CO2 -e/unit)

Emission factor
N2O
(kg CO2 -e/unit)

Regular petrol

litre

2.32

2.29

0.0136

0.0154

Premium petrol

litre

2.37

2.34

0.0137

0.0156

Petrol – default**

litre

2.33

2.30

0.0136

0.0155

Diesel

litre

2.65

2.61

0.00302

0.0435

LPG

litre

1.61

1.59

0.0159

0.00469

* Use the total CO2-e emission factor for calculating total CO2-e emissions, rather than summing the totals for CO2, CH 4 and N2O.

** The default petrol emission factor should be used if it is not possible to distinguish between regular and premium petrol use.

Assumptions

The kg CO2-e per activity unit emission factors supplied in Table 2 are derived using calorific values sourced from the New Zealand Energy Data File 2007. All emission factors incorporate relevant oxidation factors which are sourced from Energy Greenhouse Gas Emissions 1990–2006.

The default petrol factor is a weighted average of regular and premium petrol based on 2006 sales volume data from the New Zealand Energy Data File 2007. It should be used when petrol use data does not distinguish between regular and premium petrol.

As with the fuels for stationary combustion these emission factors are not full fuel cycle emission factors and do not incorporate (the Scope 3) emissions associated with the extraction, production and transport of the fuel.

Example calculation

An organisation has 15 petrol vehicles. They used 40,000 litres of regular petrol in 2006.

CO2 emissions = 40,000 * 2.29 = 91,600 kg CO2 = 91.6 tonnes CO2

CH 4 emissions = 40,000 * 0.0136 = 544 kg CO2-e = 0.544 tonnes CO2-e

N2O emissions = 40,000 * 0.0154 = 616 kg CO2-e = 0.616 tonnes CO2-e

Total CO2-e emissions = 40,000 * 2.32 = 92,800 kg CO2-e = 92.8 tonnes CO2-e

3.1.3 Transport where no fuel data is available (based on distance travelled)

If your records only provide information on kilometres travelled, and you do not have information on fuel use, the emission factors in the following table can be used. Note however that factors such as individual vehicle fuel efficiency and driving efficiency mean that kilometre based estimates of CO2-e emissions are less accurate than calculating emissions based on fuel use data. The emission factors in the below table should therefore only be used if information on fuel use is not available.

Table 3: Transport emission factors (based on distance travelled) – 2006

Vehicle size class**

Unit

Real world petrol fuel use estimate
(L/100km)

Emission factor
total CO2 -e*
(kg CO2 -e/unit)

Emission factor
CO2
(kg CO2 /unit)

Emission factor
CH 4
(kg CO2 -e/unit)

Emission factor
N2O
(kg CO2 -e/unit)

Car – small
(<1600 cc)

km

7.67

0.179

0.176

0.00104

0.00119

Car – medium
(1600–<2500 cc)

km

10.4

0.241

0.238

0.00141

0.00160

Car – large
(≥2500 cc)

km

14.2

0.330

0.326

0.00193

0.00219

Car – default***

km

10.4

0.241

0.238

0.00141

0.00160

* Use the total CO2-e emission factor for calculating total CO2-e emissions, rather than summing the totals for CO2, CH 4 and N2O.

** Example (representative) vehicle models for each of the size classes are: Small = Toyota Echo, Medium = Honda Accord, Large = Holden Commodore.

*** The default emission factor should be used if vehicle size class cannot be determined.

Assumptions

The above emission factors assume that all vehicles are petrol. The emission factors are derived by multiplying the default petrol emission factor from Table 2 by ‘real world’ fuel consumption rates11 for the petrol light vehicle fleet, based on information from The New Zealand Light Vehicle Fleet: Light Fleet Statistics 2006 (Ministry of Transport, 2007). ‘Real world’ fuel consumption rates take into account ‘real world’ effects such as driver behaviour. Due to lack of data it is not currently possible to derive ‘real world’ fuel consumption rates for vehicles which use other fuels (eg, diesel, LPG).12 The above CO2-e emission factors should therefore be applied to all vehicles (for which only kilometre travelled information is available), regardless of the type of fuel used.

The above emission factors are averages and therefore do not reflect the variability in fuel consumption rates between individual vehicles.

The default emission factor (for vehicles of unknown size) is the same as that for medium vehicles (1600–<2500 cc).13

Example calculation

An organisation has three vehicles which it owns. They are all large vehicles and travelled a total of 37,800 km in 2006.

CO2 emissions = 37,800* 0.326 = 12,322.8 kg CO2 = 12.3 tonnes CO2

CH 4 emissions = 37,800* 0.00193= 72.954 kg CO2-e = 0.0730 tonnes CO2-e

N2O emissions = 37,800* 0.00219 = 82.782 kg CO2-e = 0.0828 tonnes CO2-e

Total CO2-e emissions = 37,800* 0.330 = 12,474 kg CO2-e = 12.5 tonnes CO2-e

3.2 Scope 2: Electricity indirect emissions

3.2.1 Purchased electricity

An emission factor for the consumption of purchased electricity (by end users) is provided in Table 4. The emission factor is calculated on a calendar year basis and accounts for the emissions, from fuel combustion at thermal power stations, which are associated with the consumption of purchased electricity from the grid. It also includes a relatively small proportion of fugitive emissions from geothermal generation.

The emission factor for the consumption of purchased electricity, as well as the emission factor for transmission and distribution line losses (included below, in Table 5), have been aligned with the definitions used in the GHG Protocol.

This emission factor is sourced from the Energy Greenhouse Gas Emissions 1990–2006 publication which provides a historic record of (electricity) emission factors up to the previous calendar year.

The electricity emission factor covers purchased electricity which has been bought from an electricity supplier who sources their electricity from the national grid.14

Table 4: Emission factor for the consumption of purchased electricity – 2006

Emission source

Unit

Emission factor total CO2 -e (kg CO2 -e/unit)

Purchased electricity

kWh

0.209

Assumptions

As with the fuels for stationary combustion emission factors, this emission factor does not incorporate emissions associated with the extraction, production and transport of the fuels burnt to produce electricity.

This emission factor does not account for the emissions associated with the electricity lost in transmission and distribution on the way to the end user. Under the reporting framework of The GHG Protocol the emissions associated with transmission and distribution line losses are Scope 3 emissions. Table 5 contains an emission factor for transmission and distribution line losses.

The emission factor in Table 4 is derived from the tCO2-e/MWh generation emission factor (as opposed to the consumption emission factor) in the Energy Greenhouse Gas Emissions 1990–2006 publication. This is explained in more detail in the section below covering the transmission and distribution line losses emission factor.

Notes on the use of electricity emission factors

The emission factor provided in Table 4 is an average over the calendar year for which the emission factor relates and is used for reporting the annual emissions associated with the consumption of purchased electricity.

A grid-average emission factor best reflects the CO2-e emissions associated with the generation of a unit of electricity, purchased from the national grid, in New Zealand.

Retailer-specific electricity factors for grid electricity may be considered in the future. At this stage however, there is insufficient information to prepare such factors and no clear consensus on the advantages of this approach. In the meantime, use of a grid average factor does not ignore or refute claims of carbon neutrality or similar by some electricity retailers. Rather, these claims should be accounted for separately. It is suggested users contact the Ministry for further advice on this issue.

This factor cannot be used for calculating abatement by intervention or reducing the use of thermal generation, for an offset project for example. A marginal emission factor is more appropriate in these circumstances, because it is designed to take into account the change in electricity generation at the margin. As such, it is often a higher figure than the historical average factor as listed in Table 4. Users wanting more information on marginal electricity emission factors are advised to contact the Electricity Commission.

It is also possible that a different emission factor may be used for determining allocation under the New Zealand Emissions Trading Scheme. An allocation factor has yet to be determined at this stage, but it may need to take into account a number of different issues that could produce a different value to that listed in Table 4.

Example calculation

An organisation uses 800,000 kWh of electricity in 2006. Their Scope 2 emissions from electricity are:

Total CO2-e emissions = 800,000 * 0.209 = 167,200 kg CO2-e = 167.2 tonnes CO2-e

3.3 Scope 3: Other indirect emissions

3.3.1 Transmission and distribution line losses for purchased electricity

The transmission and distribution line losses emission factor accounts for emissions (from the generation) of the electricity lost in the transmission and distribution network due to inefficiencies in the grid. Under The GHG Protocol reporting framework emissions from the generation of electricity that is consumed in a transmission and distribution system should be reported as a Scope 3 emission by end users.

The emission factor for transmission and distribution line losses is the difference between the generation and consumption emission factors reported in Table 4.8 of the Energy Greenhouse Gas Emissions 1990–2006.15

Table 5: Transmission and distribution line losses for purchased electricity – 2006

Emission source

Unit

Emission factor total CO2 -e
(kg CO2 -e/unit)

Transmission and distribution line losses for purchased electricity

kWh

0.0197

Assumptions

This emission factor covers grid-purchased electricity, purchased by an end user. It is an average figure and therefore makes no allowance for distance from offtake-point, or other factors that may vary between individual consumers.16

This emission factor accounts for emissions from the generation of the electricity lost in the transmission and distribution network, during delivery to end users. It does not incorporate the emissions associated with the extraction, production and transport of the fuels burnt to produce the electricity.

Example calculation

An organisation uses 800,000 kWh of electricity in 2006. Their Scope 3 emissions from transmission and distribution line losses for purchased electricity are:

Total CO2-e emissions = 800,000 * 0.0197 = 15,760 kg CO2-e = 15.8 tonnes CO2-e

3.3.2 Transmission and distribution losses for distributed17 natural gas

17

The transmission and distribution losses emission factor for distributed natural gas accounts for fugitive emissions, from the transmission and distribution system, which occur during the delivery of the gas to the end user.

This emission factor is derived based on information from the Energy Greenhouse Gas Emissions 1990–2006 and New Zealand Energy Data File 2007 publications.

Table 6: Transmission and distribution losses for distributed natural gas – 2006

Emission source

Unit

Emission factor total CO2 -e
(kg CO2 -e/unit)

Transmission and distribution losses for distributed natural gas

kWh

0.0248

GJ 6.89

Assumptions

As with the distributed natural gas emission factor, the transmission and distribution losses emission factor is based on a weighted average of Maui- and Kapuni-treated natural gas.

This figure represents an estimate of the average amount of CO2-e emitted from losses associated with the delivery (transmission and distribution) of a unit of gas per unit of gas consumed through local distribution networks for 2006. It is an average figure and therefore makes no allowance for distance from offtake-point, or other factors that may vary between individual consumers.

This figure assumes that all losses are attributable to gas consumed via local distribution networks. A small amount (<1 per cent) of emissions is attributable to losses occurring from delivery of gas to consumers who are directly connected to a high-pressure transmission pipeline.18

This emission factor is therefore appropriate for use by customers who receive their gas through a local distribution network, and is not intended for customers who receive gas directly from the transmission system, or directly from a gas producer via high-pressure transmission lines.

This emission factor covers the fugitive emissions which occur during the delivery of the gas to end users. It does not cover the emissions associated with the extraction and production of the gas.

Example calculation

An organisation uses a 1,000 gigajoules of distributed natural gas in 2006. Their Scope 3 emissions from transmission and distribution losses are:

Total CO2-e emissions = 1,000* 6.89 = 6,890 kg CO2-e = 6.89 tonnes CO2-e

3.3.3 Taxis and rental cars

Business travel in taxis and rental cars is likely to be a common source of Scope 3 emissions for most businesses. As with Scope 1 emissions from transport, the most accurate way to calculate emissions is based on fuel consumption data. However this information may not be easily available, particularly for business travel in taxis. Table 7 provides emission factors for rental car and taxi travel, based on kilometres travelled, as well as an emission factor for taxi travel based on dollars spent.

Table 7: Emission factors for travel in taxis and rental cars (based on distance travelled) – 2006

Emission source

Unit

Emission factor total CO2 -e (kg CO2 -e/unit)

Rental car – small (<1600cc)

km

0.179

Rental car – medium (1600–<2500cc)

km

0.241

Rental car – large (≥2500cc)

km

0.330

Rental car – default*

km

0.241

Taxi travel – distance travelled

km

0.330

Taxi travel – dollars spent

$

0.143

* The default emission factor should be used if the vehicle size class of rental cars can not be determined.

Assumptions

The emission factors for taxis and rental cars are the same as those found in Table 3 and so the underlying assumptions are the same.

The default emission factor for rental cars is the same as that for medium vehicles (1600–<2500 cc) from Table 3. Data from the Motor Industry Association New Vehicle Sales database showed that for the period January 2002–June 2007, 58.6 per cent of rental vehicles purchased were in the medium vehicle size class.

The default emission factor for taxis is the same as that for large vehicles (1600–<2500 cc) from Table 3. Data from the Motor Industry Association New Vehicle Sales database showed that for the period January 2002–June 2007, 81.3 per cent of taxis purchased were in the large vehicle size class.

The dollars spent emissions factor is based on a national average figure of $2.30 per kilometre travelled. This figure is sourced from Taxicharge New Zealand.

Example calculation

An organisation uses rental cars to travel 12,000 km in 2006. They also spend $18,000 on taxi travel.

Total CO2-e emissions from rental cars = 12,000* 0.241 = 2,892 kg CO2-e = 2.89 tonnes CO2-e

Total CO2-e emissions from taxi travel = $18,000* 0.143 = 2,574 kg CO2-e = 2.57 tonnes CO2-e

3.3.4 Air travel

The emission factors provided in Table 8 are intended for use by organisations wishing to report their air travel emissions, based on the distance travelled per passenger. The emission factors provided below are based on emission factors published by the UK Department for Environment Food and Rural Affairs (Defra) in their Guidelines to Defra’s GHG conversion factors for company reporting publication (Defra, 2007). These are deemed to be the most suitable emission factors currently available.19 The Defra publication discusses the emission factor methodology in more detail.

Table 8: Emission factors for air travel (based on distance travelled) – 2006

Emission source

Unit

Emission factor total CO2 -e (kg CO2 -e/unit)

Domestic

km

0.159

Short haul international (<3700 km)

km

0.132

Long haul international (>3700 km)

km

0.107

Assumptions

The underlying assumptions stated in the Defra publication are made here. Further discussion on the methodology used to derive the air travel emission factors can be found at http://www.defra.gov.uk/environment/business/envrp/pdf/passenger-transport.pdf.

The emission factors contained in Table 8 are based on representative flight distances of: domestic 463 km, short haul 1108 km, and long haul 6482 km. The domestic emission factor should be applied to all domestic flights; the short haul emission factor to flights less than 3700 km, and the long haul emission factor should be applied to any flights greater in length than 3700 km.

DEFRA endorse a 9 per cent uplift factor to take into account non-direct (ie, not along the straight line between destinations) routes and delays/circling. This figure comes from the IPCC Aviation and the global Atmosphere 8.2.2.3, and is based on studies on penalties to air traffic associated with the European ATS Route Network. This figure is likely to be overstated in New Zealand (initial estimates from Airways New Zealand is that this figure is likely to be less than 5 per cent), however in the absence of a New Zealand-specific figure it is recommended that those wishing to take a conservative approach apply the 9 per cent uplift factor.

The DEFRA emission factors only take into account CO2 emissions. In line with ISO 14064-1 and The GHG Protocol reporting requirements, the emission factors provided in Table 8 are CO2-e emission factors. They have been scaled up based on the default CH 4 and N2O emission factors (for aviation fuels) sourced from the Energy Greenhouse Gas Emissions 1990–2006 publication. The percentage mark-up (used to convert to CO2-e) is 0.923 per cent. The mark up assumes that all fuel burnt is jet fuel.

The emission factors provided above do not include radiative forcing (ie, non-CO2 climate change impacts). The total climate impacts of aviation due to radiative forcing have been estimated by the IPCC to be up to 2–4 times those of CO2 alone. However the science in this area is currently uncertain and a multiplier is not used for New Zealand’s national greenhouse gas inventory reporting. As the emission factors contained in this publication are intended to be consistent with New Zealand’s national greenhouse gas inventory reporting, it is not currently deemed appropriate to apply a multiplier to account for radiative forcing.

Example calculation

An organisation makes a number of flights from Auckland to Sydney. The total distance travelled was 200,000 km.

Total CO2-e emissions from air travel = 200,000* 0.144 = 28,600 kg CO2-e = 28.6 tonnes CO2-e

3.3.5 Waste to landfill

The emission factors and methodologies provided below will assist organisations in estimating their emissions from waste disposed of at landfill. Emission factors are based on figures from New Zealand’s Greenhouse Gas Inventory 1990–2005 and methodologies are derived from IPCC good practice guidance. The (base equation) methodology provided below is termed “tier 1” under IPCC guidelines and assumes that all the potential emissions in a tonne of waste are released in the year of disposal.

Methodologies to determine emissions from wastewater treatment and solid waste incineration are not covered by this publication, as emissions are assumed to be negligible at the individual organisation level (with some exceptions for large industrial wastewater producers).

The anaerobic decomposition of organic waste in landfills generates methane (CH 4). Inventories should be adjusted to account for the landfill gas that is collected and destroyed.20 The methodologies outlined below provide for such adjustment depending on whether an organisation’s waste is sent to a landfill with (or without) a landfill gas collection system.

Methodologies

Two methodologies for determining a solid waste emission factor are provided. Choice of methodology depends on organisational knowledge of waste composition. It is preferable to know the composition of waste as it allows emissions to be more accurately quantified.21

Base equation

The base equation used in deriving the waste emission factors, as taken from the 1996 IPCC Good Practice Guidelines, is as follows:

CO2-e emissions (kg) = ((MSWT x DOC x DOCF x F x 16/12) x (1– R) x (1-OX)) x 21

Where:

MSWT = total Municipal Solid Waste (MSW) generated (kg)

DOC = degradable organic carbon

DOCF = fraction of DOC dissimilated

F = fraction of CH 4 in landfill gas

R = fraction recovered CH 4

OX = oxidation factor

21 = GWP of methane (CH 4)

Interpretation

Table 9 provides methodologies for four scenarios; where composition of an organisation’s waste is known and is or isn’t sent to a landfill with a landfill gas system, and where composition is unknown and is or isn’t sent to a landfill with a landfill gas system.

If the organisation has data on individual waste streams, but doesn’t know if the waste is going to a landfill with a gas collection system, then the default should be the factors for “without landfill gas recovery” ie, overestimate rather than potential to underestimate.

If the organisation does not know the composition of its waste but knows it is going to a landfill with a gas recovery system then it should use the default “mixed waste” emission factor found in Table 9. Note that this will be an inaccurate emission factor, at the organisation level, as it assumes the organisation’s waste matches the national average mixed municipal waste composition. If an organisation has an advanced diversion system (to recycling and composting) then this methodology will overestimate emissions. If an organisation has no diversion system, then it will underestimate emissions.

Default emission factors for “office waste” are provided in Table 9. These should be used by office-based organisations that do not have information on the composition of their waste. The higher emission factors reflect the higher proportion of organic matter (ie, paper and food) found in office waste. The default office waste emission factors assume no diversion has occurred so if an organisation has an advanced diversion system then this methodology will overestimate emissions.

Table 9: Emission factors for waste to landfill – 2006

Emission source

Data input unit

Kg CO2 e/unit

Equation

Landfilled waste of known composition (without landfill gas recovery)

Paper and textiles

kg

2.52

(0.4 * 0.5 * 0.5 * 16/12) * (1-0.1) * 21

Garden and food

kg

0.945

(0.15 * 0.5 * 0.5 * 16/12) * (1-0.1) * 21

Wood

kg

1.89

(0.3 * 0.5 * 0.5 * 16/12) * (1-0.1) * 21

Landfilled waste of known composition (with landfill gas recovery)

Paper and textiles

kg

1.53

(0.4 * 0.5 * 0.5 * 16/12) * (1-0.39.4)22 * (1-0.1) * 21

Garden and food

kg

0.572

(0.15 * 0.5 * 0.5 * 16/12) * (1-0.39.4) * (1-0.1) * 21

Wood

kg

1.14

(0.3 * 0.5 * 0.5 * 16/12) * (1-0.39.4) * 0.9 * 21

Landfilled waste – default values (without landfill gas recovery)

Mixed waste (national average)

kg

0.874

0.046223 * (1-0.1) * 21

Office waste

kg

1.5

((0.53624 * 0.4) + (0.20824 * 0.15) + (024 * 0.3)) * 0.5 * 0.5 * 16/12) * (1-0.1) * 21

Landfilled waste – default values (with landfill gas recovery)

Mixed waste (national average)

kg

0.529

0.0462 * (1-0.394) * (1-0.1) * 21

Office waste

kg

0.9

((0.53624 * 0.4) + (0.20824 * 0.15) + (024 * 0.3)) * 0.5 * 0.5 * 16/12) * (1-0.39.4) * (1-0.1) * 21

Assumptions

The emission factors provided in Table 9 are based on 2005 data, however we recommend that they are used for the 2006 reporting period, as this is the most current data available.

Example calculation

An organisation disposes of 30 tonnes of garden waste to a landfill with a gas recovery system in 2006.

Total CO2-e emissions from waste to landfill = 30,000* 0.573 = 17,190 kg CO2-e = 17.19 tonnes CO2-e


10 Approximately 92 per cent of the coal used by the commercial sector is sub-bituminous coal.

11 They have been calculated by multiplying the average Euro emissions dyno test cycle fuel consumption rate, for each vehicle size class (from the Ministry of Transport’s Vehicle Fleet Emissions Model), by a ‘real world’ scale-up factor of 1.20. The figures are based on new vehicles sold in New Zealand in 2006.

12 For the purpose of comparison in 2006 approximately 15 per cent of the light vehicle fleet was made up of diesel vehicles.

13 In 2006, 50.8 per cent of light petrol vehicles sold in New Zealand were in the medium vehicle size class, 14.9 per cent were small and 34.4 per cent were large.

14 It does not cover on-site self-generation of electricity.

15 The electricity figures reported in the Energy Greenhouse Gas Emissions 1990-2006 are rounded figures. Calculations to derive the figure reported in Table 5 are sourced from unrounded figures retrieved from http://www.med.govt.nz/upload/49905/EGHG-tables.xls.

16 Major electricity users need to be aware that a losses allowance may already be included on their electricity invoices. This may warrant the use of an alternative transmission and distribution losses emission factor.

17 “Distributed” refers to natural gas distributed via low pressure, local distribution networks.

17 “Distributed” refers to natural gas distributed via low pressure, local distribution networks.

18 See p.16 of the Energy Greenhouse Gas Emissions 1990–2006 publication for more details.

19 The Greenhouse Gas Protocol Initiative provides air travel emission factors which are in the process of being updated. The suitability of the air travel emission factors contained in this publication will be reviewed once these become available.

20 Where CH 4 is recovered and flared or combusted for energy, the CO2 emitted from the combustion process is regarded as part of the natural carbon cycle and is not counted as an emission.

21 It also allows you to take into account reductions in emissions from altering the composition of your waste (as opposed to just reducing your waste). For example, reducing the amount of paper going to landfill will result in a significantly lower emission factor for waste.

22 This figure can be found by dividing the recovered methane per year by gross emissions as found in the Supplementary Table 6.1A in the New Zealand’s Greenhouse Gas Inventory 1990–2005. These supplementary tables are anticipated to be within the next national inventory report.

23 This figure is published within the national greenhouse gas inventory supplementary table 6.1A as the Methane Generation Potential of a kg of waste.

24 These figures represent an assumed default composition (paper 53.6 per cent, garden and food 20.8 per cent and wood 0 per cent) for office waste, based on waste data from government buildings.