What GHG emission conversion factors are used in SMEasure?

Presently in SMEasure we use the Defra 2007 GHG emission conversion factors for company reporting for calculating the emissions resulting from gas and electricrity use, which are:

0.206 kg CO2 / kWh of natural gas
0.523 kg CO2 / kWh of electricity (this is the 5-year rolling average and takes into account the percentage of renewable generated electricity fed into the national grid)

The carbon emissions per kWh for natural gas will fluctuate regionally very marginally depending on the gas pressure in transmission. Natural gas emissions stay fairly constant year-to-year.

The carbon emissions per kWh for electricity will fluctuate more year-to-year, as it depend on the mixture of energy sources used to generate power. In recent years the amount of coal burnt electricity generation has increased resulting in more emissions per kWh of electricity.

The Defra 2009 GHG emission conversion factors for company reporting for calculating the emissions resulting from gas and electricity use are:

0.20417 kg CO2e / kWh of natural gas
0.54418 kg CO2e / kWh of electricity (this is the refined 5-year rolloing average for 2007 and will include renewable generated electricity fed into the grid)

There is only a marginal difference between 2007 and 2009 Defra emission factors. However, SMEasure will move to updating GHG emission conversion factors used in calculations when the latest factors are published.