ghg-inventory-1990-2013

Table 3.3.4
Uncertainty for New Zealand’s Energy sector emission estimates
Activity data
uncertainty (%)
Emission factor
uncertainty (%)
CO 2 Liquid fuels 2.61 ±0.5
Solid fuels 10.89 ±3.5
Gaseous fuels 6.95 ±2.4
Fugitive – geothermal 5.00 ±5.0
Fugitive – venting/flaring 6.95 ±2.4
Fugitive – oil transport 5.00 ±50.0
Fugitive – transmission and distribution 6.95 ±5.0
CH 4 Liquid fuels 2.61 ±50.0
Solid fuels 10.89 ±50.0
Gaseous fuels 6.95 ±50.0
Biomass 5.00 ±50.0
Fugitive – geothermal 5.00 ±5.0
Fugitive – venting/flaring 6.95 ±50.0
Fugitive – coal mining 10.89 ±50.0
Fugitive – transmission and distribution 6.95 ±5.0
Fugitive – other leakages 5.00 ±50.0
Fugitive – oil transportation 5.00 ±50.0
N 2 O Liquid fuels 2.61 ±50.0
Solid fuels 10.89 ±50.0
Gaseous fuels 6.95 ±50.0
Biomass 5.00 ±50.0
New Zealand uses the percentage difference between annual calculated consumer energy
from supply-side surveys and annual observed consumer energy from demand-side
surveys to estimate activity data uncertainty. As a result, activity data uncertainty can
vary significantly from year to year.
3.3.6 Fuel combustion: Energy industries (CRF 1.A.1)
Description
This category includes combustion for public electricity and heat production, petroleum
refining and the manufacture of solid fuels and other energy industries. The latter
subcategory includes estimates for natural gas in oil and gas extraction and from natural
gas in synthetic petrol production. The excess CO 2 removed from Kapuni gas at the
Kapuni gas treatment plant has also been reported under the manufacture of solid fuels
and other energy industries subcategory because of confidentiality concerns.
In 2013, emissions in category 1.AA.1 Energy industries totalled 6,768 kt CO 2 -e (21 per
cent of the Energy sector emissions). Emissions from energy industries have increased
775 kt CO 2 -e (13 per cent) since the 1990 level of 5,993 kt CO 2 -e. Subcategory 1.AA.1.A
Public electricity and heat production accounted for 5,521 kt CO 2 -e (82 per cent) of the
emissions from the energy industries category in 2013. This is an increase of 2,028 kt
CO 2 -e (58 per cent) from the 1990 level of 3,493 kt CO 2 -e.
Changes in emissions between 2012 and 2013
Between 2012 and 2013, there was a decrease of 1,096 kt CO 2 -e (17 per cent) in
emissions from 1.AA.1.A Public electricity and heat production. This was largely
New Zealand’s Greenhouse Gas Inventory 1990–2013 59