CO2 Conversion Factors

I like to monitor my domestic CO2e emissions. I know this might seem sad but its a relic from when I used to do it for a major public sector organisation’s annual report.

When I was with EDF I used 0.35156 to convert kWh of electricity to kg CO2e and 0.18416 to convert kWh of gas to kg CO2e (2017 figures from These figures change from year to year depending on the UK fuel mix for generating electricity. My assumption is that using Bulb my CO2e for electricity is 0 and 0.16574 for gas. Is this correct?

Also I’m not quite sure why the figure Bulb are using for comparison with other suppliers in their Annual Green Impact Report is .254 kg per kWh, should they/you not be using 0.35156?

Hi @DGP1000 - we don’t think that’s sad - we think that’s awesome.

Yes, you’re right. At Bulb, electricity is 100% carbon free and gas is 0.166 kg/kWh.

In the green impact report, we used the national fuel mix report from BEIS (here) to work out the CO2 emissions of the average UK home (0.254 kg per kWh of electricity). There’s more info on that in our blog post on the impact report.

Thanks for sharing the conversion factors - we haven’t seen those before and will look into them!