How do I calculate Scope 3 Category 3 for T&D losses and well-to-tank fuel emissions in India?
Category 3 has two parts for most companies. Multiply the litres, kg or scm of fuel in your Scope 1 by well-to-tank factors, and multiply the grid kWh in your Scope 2 by the T&D loss rate and the grid factor. Name the well-to-tank database you use and the country its values describe.
The four activities in Category 3
A typical factory reports the first and third, and either estimates the second or explains why it is left out.
- Upstream emissions of fuels you burn: extraction, refining and transport of diesel, coal, PNG and so on, before they reach you. This is well-to-tank (WTT).
- Upstream emissions of fuels burnt in power plants that made your electricity.
- Generation of electricity lost in transmission and distribution (T&D).
- Generation of electricity you bought and resold to end users. This applies only to utilities and power traders.
Well-to-tank emissions from fuels
WTT emissions = fuel quantity x WTT factor, using the same quantities as your Scope 1. The UK government conversion factors publish WTT values for many fuels and are also used outside the UK. They describe UK supply chains, so for Indian fuel they are an approximation; say so in your method note.
WTT factors are in kg CO2e, because methane leaks from extraction matter here.
T&D losses on grid electricity
T&D emissions = grid kWh consumed x T&D loss rate x grid factor, using the CEA all India T&D loss for the year. A stricter version uses loss / (1 minus loss). The CEA grid factor is per kWh of net generation, so this is not counted in Scope 2.
What to write in the report
- Which of the four activities you included, and why any are excluded.
- The WTT database and edition, and the CEA editions for the loss rate and grid factor.
- That the WTT part is CO2e and the T&D part is CO2 if you use the CEA factor.
Worked example: a factory with diesel and grid power (illustrative)
- Diesel burnt in a year: 10,000 litres
- WTT: 10,000 x 0.6 kg CO2e per litre (illustrative only, not an official DESNZ value) = 6,000 kg CO2e
- Grid electricity: 100,000 kWh at an illustrative 18% T&D loss (not a CEA value)
- T&D: 100,000 x 0.18 x 0.710 = 12,780 kg CO2
- Category 3 total: 6.0 t + 12.8 t = about 18.8 t
- For comparison, Scope 1 diesel is 10,000 x 2.68 = 26,800 kg CO2
Take the WTT value from the current DESNZ edition and the loss rate from the latest CEA General Review when you report; the total mixes a CO2e figure and a CO2 figure, which you should state.
What Senseible does here
Senseible reads the fuel quantities and grid kWh behind your Scope 1 and 2 from invoices and bills, which are the inputs to Category 3. It does not hold WTT or T&D loss factors and does not calculate Category 3.
Sources: GHG Protocol Technical Guidance for Calculating Scope 3 Emissions (2013), Category 3, UK Government GHG Conversion Factors for Company Reporting (DESNZ), WTT factors, CEA General Review, All India Electricity Statistics (T&D losses)
Last reviewed 2026-10-15. The DESNZ factors are reissued every year and the CEA T&D loss rate changes yearly; update both figures before reporting.