The Greenhouse Indicator

Methodology

The weekly greenhouse gas indicator is believed to be the first of its kind in the world. It uses actual data to determine an accurate figure for the greenhouse gas emissions produced from the three main sources of emissions from energy: coal, natural gas and petroleum. The methodology for calculating weekly emissions from these fuels in NSW, Queensland and Victoria is detailed below.

Coal

Used for electricity generation

Emissions are calculated from the electricity generated by each coal-fired power station in the State using detailed market data from the National Electricity Market Management Company (NEMMCO). Emissions factors are based on the ACIL Tasman Report on NEM Generator Costs, prepared for Inter Regional Planning Committee (IRPC) and NEMMCO, 2005.

Natural Gas

New South Wales and Queensland

Used for electricity generation

Emissions from electricity generation are calculated from the electricity generated by gas-fired power stations in the State using detailed market data from the National Electricity Market Management Company (NEMMCO). Emissions factors are based on the ACIL Tasman, Report on NEM generator costs, prepared for Inter Regional Planning Committee (IRPC) and NEMMCO, 2005. Unlike in Victoria, regular information on total gas use is not currently available for NSW and Queensland.

Victoria

Used for heating (domestic, commercial and industrial), electricity generation and cooking

Emissions are calculated from the natural gas consumed in the State using detailed gas market data from VENCorp. VENCorp data covers some 99% of the natural gas used in Victoria. A small amount (<5%) of the natural gas measured each week is used in non-thermal applications, such as the production of methanol and plastic bags. Emissions factors are based on the Australian Greenhouse Office 2004 Factors and Methods Workbook published in the Greenhouse Challenge Plus Emissions Worksheet.

Petroleum

Used for automotive gasoline, diesel (automotive and industrial), LPG (transport and non-transport), aviation (gasoline and turbine) and fuel oil

This is determined on detailed figures provided by the petroleum industry on monthly sales to the Australian Government’s Department for Industry and Tourism. Rolling averages of each month's data are used to obtain weekly figures. The averaged monthly figures offer an excellent indication of weekly volumes of petroleum burnt since petroleum sales from week to week are relatively stable. Also, the exact time that emissions occur from the burning of petroleum is uncertain due to the environment's ability to store it. Emissions factors are based on the Australian Greenhouse Office 2004 Factors and Methods Workbook published in the Greenhouse Challenge Plus Emissions Worksheet.