Understanding Emission Factor using Electricity Maps api

[Shreyansh Jain]

Hi Team,

I am using Electricity map api to get the Emission factor for my Cloud Provider region and trying to compare it with what CCF is using if Electricity Map api token is not configured in the .env file.

On Calling the Emap api directly, i am getting Carbon intensity.

After going through CCF codebase, i found out that you are doing this : response.carbonIntensity / 1000,

after getting emap api response which for me is coming as 0.422. But in CCF we are using 0.000225

for the same region.

While i get it that the constant value will be different from latest emap value, Can you please let me know the extra the decimal value mismatch i.e. the extra 3 zeroes in CCF constants for region Emission factor?

Thanks,

Shreyansh Jain

[Cloud Carbon Footprint]

Hi Shreyansh,

Thanks so much for bringing this up. In fact you are correct about this. Looks like we did add the wrong calculation here. Since the EM value is returned in `gCO2eq/kWh` and CCF uses `MTCO2eq/kWh`, we need to divide by 1000000 rather than just 1000. Appreciate your contribution! We will create a new issue to fix this.

Thanks,

The CCF Team at Thoughtworks

[Shreyansh Jain]

Hi Team, 

Thanks for acknowledging this. 

Also, while looking into the same, i tried comparing the Carbon intensity value that Emap api provides and what we use in constants of CCF codebase, here's what i found out : 

Carbon Intensity for Australia region (AU-NSW) : 0.477

Emission factor for same region in CCF constants : 0.96

Can you please let me know if this deviation from Emap value and constants is correct or expected?

Thanks.

[Cloud Carbon Footprint]

Hi Shreyansh,

This deviation is expected as the sources for the emissions factors that CCF uses by default and that Electricity Maps uses are different. The default values used in CCF are sourced from publicly available data sources that uses average instead of marginal emissions factors. You can read more about it and the list of these sources in our Emissions Factors documentation.

Another thing to note is that Electricity Maps API also returns carbon intensity values based on a given time (via timestamp) for that region as well. So these numbers will always be historical or realtime, causing them to further differ from the default CCF constants that are only based on averages from the past year. Therefore, the numbers between the two carbon intensity options will differ, but the order of magnitude should be similar. This is why we have provided the Electricity Maps integration as a more accurate option for carbon intensity data.

Hope that helps!

Best,

The CCF Team at Thoughtworks