Our sub-meters add up to less than the main electricity meter. Which do we report?
Report the main meter, the discom bill. The gap is normal: cable and transformer losses, unmetered loads such as lighting, and meter error. For allocating emissions to lines or tenants, share the gap in proportion to sub-meter readings and say so. A gap that keeps growing is worth investigating.
Typical causes
- Losses in internal cables and transformers.
- Loads not on any sub-meter.
- Sub-meters not calibrated or read on different days.
What to record
Monthly main meter total, sum of sub-meters and the difference in percent. A verifier will ask why it moved.
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, and labels estimates as estimates.
Sources: CEA CO2 Baseline Database, version 21.0, GHG Protocol Corporate Standard
Last reviewed 2026-10-23.