How do I calculate the emissions of a pottery kiln firing?
For an electric kiln, multiply the kWh per firing, from a meter or the controller log, by 0.710 kg CO2 per kWh. For a gas kiln, multiply the LPG or PNG used by its default factor. Divide by the pieces in the load for a per-piece figure.
Getting the energy
- Electric kiln: a plug-in or sub-meter, or rated power times firing hours as an estimate.
- Gas kiln: cylinder weight before and after, or the gas meter.
- Wood kiln: wood weight, whose CO2 is biogenic and reported separately.
Bisque and glaze
Work fired twice, biscuit then glaze, carries both firings. Spread each firing over the pieces it held.
Fuller loads
A kiln uses much the same energy to reach temperature whether it is full or half empty, so packing it fully spreads that energy over more pieces.
Worked example: one glaze firing (illustrative inputs)
- Electric kiln: 18 kWh per firing x 0.710 = 12.78 kg CO2
- Pieces in the firing: 40
- Per piece: 12.78 / 40 = 0.320 kg CO2
- LPG kiln instead: 9 kg LPG x 2.98 = 26.82 kg CO2, 0.670 kg per piece
Energy per firing is illustrative; read your meter or weigh your cylinder.
What Senseible does here
Senseible reads electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and diesel, LPG and gas invoices (IPCC 2006 defaults) into a dated, fingerprinted Scope 1 and 2 record for each site. Intensity per unit uses the activity count you enter, and estimates are labelled as estimates.
Sources: GHG Protocol Corporate Standard, IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-21.