How do I calculate the emissions of an organic waste converter machine?
Multiply the machine's electricity, from a sub-meter or rated power and hours, by 0.710 kg CO2 per kWh, and divide by kg of wet waste processed. Composting the output releases a little methane and N2O. Landfill emissions avoided are not deducted.
What to count
- Electricity for the shredder, mixer and heater.
- Additives such as sawdust or culture, as bought-in inputs.
- Methane and N2O from the curing stage, from IPCC composting defaults if you calculate them.
Avoided landfill
Sending food waste to a converter instead of a landfill avoids methane, but that is an avoided emission. Report it separately, not as a reduction of your inventory.
Per kg
Divide by kg of wet waste fed in, from the daily log, and report the kWh per kg so you can compare machines.
Worked example: housing society converter (one month, illustrative inputs)
- Electricity: 1,800 kWh x 0.710 = 1,278 kg CO2
- Wet waste processed (kg): 9,000
- Total: 1,278 / 9,000 = 0.142 kg CO2 per kg of waste
Inputs are illustrative; use the sub-meter and waste log.
What Senseible does here
Senseible keeps waste manifests, transport invoices and treatment bills as evidence on the Scope 3 trail and reads electricity bills for on-site equipment into Scope 2. Avoided emissions are never subtracted from the inventory.
Sources: 2006 IPCC Guidelines, Volume 5 Waste, Chapters 2 and 5, CEA CO2 Baseline Database, version 21.0, GHG Protocol Corporate Value Chain (Scope 3) Standard
Last reviewed 2026-10-21.