New Zealand emission factors are based on gross calorific value. Energy activity data and emission factors in New Zealand are conventionally reported in gross terms, with some minor exceptions. The convention adopted by New Zealand to convert gross calorific value to net calorific value follows the Organisation for Economic Co-operation and Development and International Energy Agency assumptions:
- net calorific value = 0.95 × gross calorific value for coal and liquid fuels
- net calorific value = 0.90 × gross calorific value for gas.
Emission factors for gas, coal, biomass and liquid fuels used by New Zealand are shown in Tables A2.1–A2.3.
|Kapuni low temperature separator||84.10||22.94||1|
|Weighted average for distributed gas||53.59||14.61|
|Methanol – mixed feed (1990–1994)||62.44||17.00||3|
|Methanol – low temperature separator (1990–1994)||83.97||22.94||3|
|Waihapa/Ngaere + Tariki/Ahuroa||54.85||14.96||3|
|Petrol – premium||66.91||18.25||4|
|Diesel (50 ppm)||69.53||18.96||4|
|Fugitive – flared||65.10||17.75||4|
|Liquefied petroleum gas||60.43||16.48||2|
|Heavy fuel oil||73.90||20.16||4|
|Light fuel oil||72.86||19.87||4|
|All sectors (sub-bituminous)||91.20||24.87||2|
|All sectors (bituminous)||88.80||24.22||2|
|All sectors (lignite)||95.20||25.96||2|
1. Derived by the transmission operator (Vector Ltd) through averaging daily gas composition data
2. New Zealand Energy Information Handbook (Eng et al, 2008)
3. Specific gas field operator
4. New Zealand Refinery Company
5. IPCC guidelines (1996)
|Electricity – boilers||0.09||IPCC Tier 2 (Table 1–15) natural gas boilers|
|Electricity – large turbines||5.40||IPCC Tier 2 (Table 1–15) large gas-fired turbines >3MW|
|Commercial||1.08||IPCC Tier 2 (Table 1–19) natural gas boilers|
|Residential||0.90||IPCC Tier 2 (Table 1–18) gas heaters|
|Domestic transport (compressed natural gas)||567.00||IPCC Tier 2 (Table 1–43) passenger cars (uncontrolled)|
|Other stationary (mainly industrial)||1.26||IPCC Tier 2 (Table 1–16) small natural gas boilers|
|Electricity – residual oil||0.86||IPCC Tier 2 (Table 1–15) residual oil boilers – normal firing|
|Electricity – distillate oil||0.86||IPCC Tier 2 (Table 1–15) distillate oil boilers – normal firing|
|Industrial (including refining) – residual oil||2.85||IPCC Tier 2 (Table 1–16) residual oil boilers|
|Industrial – distillate oil||0.19||IPCC Tier 2 (Table 1–16) distillate oil boilers|
|Industrial – liquid petroleum gas||1.05||IPCC Tier 2 (Table 1–18) propane/butane furnaces|
|Commercial – residual oil||1.33||IPCC Tier 2 (Table 1–19) residual oil boilers|
|Commercial – distillate oil||0.67||IPCC Tier 2 (Table 1–19) distillate oil boilers|
|Commercial – liquid petroleum gas||1.05||IPCC Tier 2 (Table 1–18) propane/butane furnaces|
|Residential – distillate oil||0.67||IPCC Tier 2 (Table 1–18) distillate oil furnaces|
|Residential – liquid petroleum gas||1.05||IPCC Tier 2 (Table 1–18) propane/butane furnaces|
|Agriculture – stationary||0.19||IPCC Tier 2 (Table 1–49) diesel engines (agriculture)|
|Liquid petroleum gas||28.50||IPCC Tier 2 (Table 1–44) passenger cars (uncontrolled)|
|Petrol||18.53||IPCC Tier 2 (Table 1–27) passenger cars (uncontrolled – mid-point of average g/MJ)|
|Diesel||3.8||IPCC Tier 2 (Table 1–32) passenger cars (uncontrolled – g/MJ)|
|Navigation (fuel oil and diesel)||6.65||IPCC Tier 2 (Table 1–48) ocean-going ships|
|Aviation fuel/kerosene||1.90||IPCC Tier 2 (Table 1–48) jet and turboprop aircraft|
|Electricity generation||0.67||IPCC Tier 2 (Table 1–15) pulverised bituminous combustion – dry bottom, wall fired|
|Cement||0.95||IPCC Tier 2 (Table 1–17) cement, lime coal kilns|
|Lime||0.95||IPCC Tier 2 (Table 1–17) cement, lime coal kilns|
|Industry||0.67||IPCC Tier 2 (Table 1–16) dry bottom, wall fired coal boilers|
|Commercial||9.50||IPCC Tier 2 (Table 1–19) coal boilers|
|Residential||285.00||IPCC Tier 1 (Table 1–7) coal – residential|
|Wood stoker boilers||14.25||IPCC Tier 2 (Table 1–16) wood stoker boilers|
|Wood – fireplaces||285.00||IPCC Tier 1 (Table 1–7) wood – residential|
|Biogas||1.08||IPCC Tier 2 (Table 1–19) gas boilers|
|Electricity generation||0.09||IPCC Tier 1 (Table 1–8) natural gas – all uses|
|Commercial||2.07||IPCC Tier 2 (Table 1–19) natural gas boilers|
|Residential||0.09||IPCC Tier 1 (Table 1–8) natural gas – all uses|
|Domestic transport (compressed natural gas)||0.09||IPCC Tier 1 (Table 1–8) natural gas – all uses|
|Other stationary (mainly industrial)||0.09||IPCC Tier 1 (Table 1–8) natural gas – all uses|
|Electricity – residual oil||0.29||IPCC Tier 2 (Table 1–15) residual oil boilers – normal firing|
|Electricity – distillate oil||0.38||IPCC Tier 2 (Table 1–15) distillate oil boilers – normal firing|
|Industrial (including refining) – residual oil||0.29||IPCC Tier 2 (Table 1–16) residual oil boilers|
|Industrial – distillate oil||0.38||IPCC Tier 2 (Table 1–16) distillate oil boilers|
|Commercial – residual oil||0.29||IPCC Tier 2 (Table 1–19) residual oil boilers|
|Commercial – distillate oil||0.38||IPCC Tier 2 (Table 1–19) distillate oil boilers|
|Residential (all oil)||0.19||IPCC Tier 2 (Table 1–18) furnaces|
|Liquid petroleum gas (all uses)||0.57||IPCC Tier 1 (Table 1–8) oil – all sources except aviation|
|Agriculture – stationary||0.38||IPCC Tier 2 (Table 1–49) diesel engines – agriculture|
|Liquid petroleum gas||0.57||IPCC Tier 1 (Table 1–8) oil – all sources except aviation|
|Petrol||1.43||IPCC Tier 2 (Table 2.7 in GPG (IPCC, 2000))
US gasoline vehicles (uncontrolled)
|Diesel||3.71||IPCC Tier 2 (Table 2.7 in GPG (IPCC, 2000)) all US diesel vehicles|
|Fuel oil (ships)||1.90||IPCC Tier 2 (Table 1–48) ocean going ships|
|Aviation fuel/kerosene||1.90||IPCC Tier 1 (Table 1–8) oil – aviation|
|Electricity generation||1.52||IPCC Tier 2 (Table 1–15) pulverised bituminous combustion – dry bottom, wall fired|
|Cement||1.33||IPCC Tier 1 (Table 1–8) coal – all uses|
|Lime||1.33||IPCC Tier 1 (Table 1–8) coal – all uses|
|Industry||1.52||IPCC Tier 2 (Table 1–16) dry bottom, wall fired coal boilers|
|Commercial||1.33||IPCC Tier 1 (Table 1–8) coal – all uses|
|Residential||1.33||IPCC Tier 1 (Table 1–8) coal – all uses|
|Wood (all uses)||3.80||IPCC Tier 1 (Table 1–8) wood/wood waste – all uses|
|Biogas||2.07||IPCC Tier 2 (Table 1–19) natural gas boilers|
A2.1 Emissions from liquid fuels
A2.1.1 Activity data and uncertainties
The Delivery of Petroleum Fuels by Industry Survey conducted by the Ministry of Economic Development has a ±5 per cent uncertainty associated with the sectoral energy allocation. However, certainty is likely to be greater for the annual totals (Ministry of Economic Development, 2006).
As the survey is run as a census there is no sampling error. The two main sources of non-sample error are the respondent and the processing error explained below.
- Respondent error: The Ministry of Economic Development makes every effort to confirm values supplied by respondents, and given assurances of accuracy. Statistics New Zealand is bound to accept them. If a discrepancy is discovered at a later date, revised values are supplied at the earliest possible opportunity.
- Processing error: The Ministry of Economic Development has thorough checking procedures to ensure that the risk of processing errors is minimised.
A2.1.2 Emission factors and uncertainties
Carbon dioxide emission factors are described in Table A2.1. The CO2 emission factors for oil products are from the New Zealand Refining Company, import data from industry and from Eng et al (2008). The New Zealand Refining Company estimates a ±5 per cent uncertainty in emission factors (Ministry of Economic Development, 2006).
A2.2 Emissions from solid fuels
A2.2.1 Activity data and uncertainties
The Quarterly Statistical Return of Coal Production and Sales conducted by the Ministry of Economic Development on behalf of Statistics New Zealand is an ongoing quarterly survey. The survey began in 1981. The survey is a full coverage of the sector and, therefore, has no sampling errors. Non-sampling errors in the survey data may result from errors in the sample frame (eg, units with the incorrect Australian New Zealand Standard Industrial Classification), respondent error (eg, incorrect values supplied) and errors made during processing survey results or non-response imputation. The Ministry of Economic Development adopts procedures to detect and minimise these potential errors.
The process of dividing coal use between different sectors will introduce greater uncertainty than the uncertainty in total coal sales. Uncertainty is also introduced from the assumption that coal used by sector is an average of the different ranks. These assumptions are thought to introduce an uncertainty of ±5 per cent (Ministry of Economic Development, 2006).
The sectoral partitioning used for coal was examined in 2003 by the Ministry for the Environment. There was concern in extrapolating sectoral allocations from 1995 to 2002 given some probable changes in sectoral coal usage. However, New Zealand coal industry experts did not consider a survey could be justified because of the difficulty and expense in collating and verifying data from a number of sectors. In addition, the major categories of coal exports, coal used by the residential sector and coal used for steel production and electricity generation are all known accurately and are not affected by the sectoral partitioning. In 2009, the Ministry of Economic Development took over the New Zealand Coal Sales and Production Quarterly Survey. Prior to 2009, when Statistics New Zealand ran the survey, seven sectors were used. The survey now splits coal sold into over 20 sectors using the Australian and New Zealand Standard Industry Classification 2006 classification (Australian Bureau of Statistics and Statistics New Zealand, 2006).
A2.2.2 Emission factors and uncertainties
The CO2 emission factors for coal are shown in Table A2.1. The non-CO2 emission factors are shown in Tables A2.2 and A2.3. The estimated uncertainty in coal emission factors is ±3 per cent (Ministry of Economic Development, 2006). An uncertainty of ±2 per cent is used for the sub-bituminous coal used in public electricity generation. All New Zealand emissions’ factors are ±2 per cent of the IPCC (1996) default values.
A2.3 Emissions from gaseous fuels
A2.3.1 Activity data
Vector Limited, a gas transmission and distribution company, has contracts with large gas users that allow metering errors of ±2 per cent. Whenever the error between the meter reading and actual gas supplied exceeds 2 per cent, adjustments are made to the reported quantities of gas supplied. Consequently, uncertainty is assumed to have an upper limit of ±2 per cent (Ministry of Economic Development, 2006).
A2.3.2 Emission factors
As discussed in section 3.3, New Zealand now uses the gas production of all fields to support the calculation of a weighted average annual CO2 emission factor for natural gas. This average emission factor is applied to a number of categories in the energy sector, such as the manufacturing industries and construction category.
The emission factors for each gas stream are shown in Table A2.1. The CO2 emission factors for distributed gas are shown in Table A2.4.
This is calculated based on all the gas production fields (Ministry of Economic Development, 2009b).
A2.4 Energy balance for year ended December 2008
|Converted into Petajolues using Gross Calorific Values||Coal||Oil||Natural Gas||Renewables||Electricity||Waste Heat||TOTAL|
|Bituminous||Sub-bitum.||Bituminous & Sub-bitum.||Lignite||Total||Crudes/
|Petrol||Diesel||Fuel Oil||Av. Fuel/
|TOTAL PRIMARY ENERGY||0.13||59.08||76.60||3.80||80.40||233.92||9.19||39.12||37.91||-22.65||-27.27||7.64||277.86||159.94||80.32||113.21||0.32||3.81||2.87||40.42||240.95||1.21||760.36|
|Losses and Own Use||-0.03||-0.03||-0.55||-0.98||1.23||0.01||-0.39||-8.05||-8.74||-5.87||-6.00||-6.00||-20.30||-40.93|
|CONSUMER ENERGY (calculated)||17.53||3.80||21.33||8.64||108.77||113.45||7.01||13.73||0.00||251.38||52.20||9.76||0.32||0.00||0.28||36.00||46.36||137.29||0.00||508.57|
|Agriculture and Hunting||1.73||0.01||1.74||0.80||5.68||0.00||0.15||6.63||1.62||6.31||16.30|
|Other Primary Industry||0.01||3.44||0.31||0.00||3.76||0.11||1.39||5.26|
|Wood, Pulp, Paper and Printing||5.40||12.38||17.78|
|Building and Construction||0.01||2.06||0.01||0.05||2.13||0.11||0.78||3.02|
|CONSUMER ENERGY (observed)||20.62||4.85||25.46||0.00||8.64||110.96||109.82||8.25||14.78||0.00||252.44||48.46||0.00||9.76||0.32||0.00||0.28||36.00||46.36||138.20||0.00||510.93|
A2.5 Fuel Flow Diagrams for year ended December 2008
Figure A2.1 New Zealand coal energy flow summary for 2008
This figure provides a schematic diagram of New Zealand’s coal production, delivery and use.
Figure A2.2 New Zealand oil energy flow summary for 2008
1. This difference is the own use of fuels at the Refinery. These fuels (asphalt, fuel oil, refinery gas and natural gas) are accounted for under the category 'Energy Industries' for liquids fuels and natural gas. This will consequently lead to the statistical difference for liquid fuels and natural gas being larger than they actually are.
This figure provides a schematic diagram of New Zealand’s crude oil and feedstocks, refinery, finished products and use
Figure A2.3 New Zealand gas energy flow summary for 2008
1. Gas Venting and Flaring consists of venting and flaring at gas and oil fields, flaring at the New Zealand Refining Company (NZRC), and venting at the Kapuni Gas Treatment Plant (KGTP). These numbers are combined to protect the confidentiality of the companies involved . The data from the two later of these three, does not originate from the "Gross Production" number. This will therefore lead to the statistical difference between calculated and observed gas neing larger than it actually is.
2. This category also consists of the combustion of 'refinery gas'. This is a synthetic gas produced gas produced by the NZRC through cracking, reforming and other processes. This 'refinery gas' is not a natural gas but is placed within the 'natural gas category'. It does not originate from the gross production figure and will therefore lead to the statistical difference between calculated and observed gas being larger than it actually is.
This figure provides a schematic diagram of New Zealand’s gas production, delivery and use.