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Climate
change
71
Energy Supply Footprint
The Energy Supply Footprint is an estimate of the total
supply chain greenhouse gas emissions associated with
the electricity and gas supplied by AGL to its customers.
The Energy Supply Footprint covers greenhouse gas
emissions resulting from the production, transportation,
distribution and consumption of electricity and gas.
Electricity Supply Footprint
Greenhouse gas emissions are produced during the generation of
electricity (primarily carbon dioxide) from the combustion of fossil
fuels such as coal and natural gas. Energy losses occur across the
energy supply system (transmission and distribution systems, and
power stations’ auxiliary loads).
Power stations therefore have to generate more electricity than is
used by end-use consumers to cover the losses associated with the
transmission and distribution networks used to deliver electricity to
the customers. The direct (physical) emissions occur at the point of
generation (power stations), where the fuel is combusted. There are
few direct emissions from transmission and distribution, and there
are no direct greenhouse gas emissions at the consumer end of the
supply chain.
The Energy Supply Footprint emissions associated with the provision
of electricity to AGL’s customers in FY2012 has decreased by 3% to
35.6 MtCO
2
e compared to the previous year. This is largely due to
a decrease in generation intensity (as documented in the National
Greenhouse Accounts factors), with supply volumes remaining fairly
constant year on year at 33 TWh.
Gas Supply Footprint
In the case of gas supply, greenhouse gas emissions arise from
production and processing at gas fields, transmission, distribution,
and when gas is combusted by AGL’s customers in their homes
and businesses.
During gas production, there is some venting of carbon dioxide and
methane at the gas field, minor fugitive emissions during processing,
and the combustion of some natural gas to operate processing
equipment. Further emissions occur during transmission and
distribution, comprising fugitive emissions and emission arising from
the use of additional natural gas in compressors along the pipelines.
At the consumer end of the supply chain, the combustion of natural
gas produces the bulk of the supply chain greenhouse gas emissions.
The Energy Supply Footprint emissions associated with the provision
of gas to AGL’s customers has decreased by 13% compared to
FY2011 to 10.9 MtCO
2
e, in line with a 14% decrease in gas supply
volumes. The intensity supplied to AGL customers in FY2012 has
remained relatively constant compared with FY2011.
Note
1 In 2011, AGL revised the methodology used to calculate the AGL Energy Supply
Footprint. The values provided in 2012 are calculated using this new methodology,
and for consistency, historical values have also been recalculated.
The Gas Supply Footprint includes all supply chain and combustion emissions
associated with the supply of electricity and natural gas by AGL Energy and its
wholly owned subsidiaries to mass market, commercial and industrial, and wholesale
customers. Electricity and gas supplied by ActewAGL (of which AGL is a 50%
partner) are excluded from the Supply Footprint. Emissions associated with the
wholesale supply of natural gas (by AGL) to AGL-operated power stations are
also excluded, to avoid double counting (the Electricity Supply Footprint includes
upstream and generation emissions from supplying electricity). These scope 1 and
scope 3 emissions are included in AGL’s Operational Footprint.
Gas Supply Footprint
1,2
Source
Emissions (MtCO
2
e)
FY09 FY10 FY11 FY12
Production
2.0
1.9
1.7
1.4
Transmission and distribution
1.3
1.2
1.2
1.1
Consumption
9.4
9.6
9.7
8.4
Total
12.7
12.7 12.6 10.9
Notes
1 The Gas Supply Footprint estimates all supply chain and combustion emissions
associated with the natural gas that AGL sold to its customers during the period.
Estimates are calculated using emission factors and Australian greenhouse gas
inventory data published by the Commonwealth Department of Climate Change
and Energy Efficiency.
2 During FY2012, AGL became aware that the published scope 3 greenhouse gas
emission factors published by the Commonwealth for natural gas consumption
in each state do not include fugitive emissions from the operation of low pressure
distribution networks. AGL has therefore estimated these emissions from data
in the Australian Greenhouse Gas Inventory, and has adjusted data reported in
previous reporting periods accordingly.
3 Values may not sum due to rounding.
Electricity Supply Footprint
1,2
Source
Emissions (MtCO
2
e)
FY09 FY10
FY11 FY12
Generation
35.1
34.7
33.2
32.2
Transmission and distribution
2.8
3.5
3.3
3.4
Consumption
0.0
0.0
0.0
0.0
Total
37.9 38.2
36.5
35.6
Notes
1 The Electricity Supply Footprint estimates the life cycle greenhouse gas emissions
associated with the electricity that AGL sold to its customers during the period.
Estimates are calculated using emission factors published by the Commonwealth
Department of Climate Change and Energy Efficiency.
2 Values may not sum due to rounding.
Carbon exposure