Adding Well-to-tank calculations

16 October 2019

[ sustainability   footprint   impact   ]

The other day whilst was updating my terribly nerdyvery responsible excel on C02 emissions I realised I was completely missing the emissions from ‘Well-to-tank’ (WTT). So I added it, and found a great source for CO2 emission data along the way…


Well-to-tank is the concept of emissions from getting the fuel from out of the ground, or point of generation, to the fuel tank in your vehicle, or point of usage.

This is in addition to the CO2 emitted from using the fuel itself. So, not only does petrol release CO2 when burnt, but in addition, it has previously required energy to get into your fuel tank, and thus released CO2 beforehand.

The impact is non-trivial as you will see, particularly since I was using purely chemical means to find the CO2 emitted from my vehicles. Really, for more info, Wikipedia does the job just fine.


As part of my searches for a reliable source, I found the UK Government already releases a great set of data for companies to use in calculating their own emissions, and it is quite complete too, using CO2 equivalents instead of just CO2! It is released annually by the Department for Business, Energy & Industrial Strategy, and here is the 2019 Conversion Factors.

This is one of the moments I really appreciate the website, it has a wealth of information and is honestly a breeze to use compared to any other governmental website. These conversion factors even include the minor use of biofuels mixed into the pump fuels and sections for CO2 emission from landfill and waste water usage.

The impact can be seen in the table below, but suffice to say its made the vehicular emissions much worse, ~20% worse!

On the other hand it would appear that the UK Grid was less CO2 emitting than what I had thought, so a silver lining, I guess.

I still have to find a good, easy to use calculation/source for the emissions regarding flights, but this governmental resource has opened up some new possibilities for a more complete approach to calculating my emissions down the line.

Emission type Old New Base WTT New Total % Change
Diesel [kg/L] 2.68 2.594 0.617 3.211 120%
Petrol [kg/L] 2.31 0.209 0.599 2.808 122%
Gas [kg/m3] 2.27 2.036 0.264 2.300 101%
Electricity [kg/kwh] 0.53 0.256 0.022 0.277 53%

Copyright © 2023 Pandalism