How do we prove the CO2 saving from replacing high-bay lights with LEDs?
Count fittings and wattage before and after, multiply by operating hours to get kWh, then use 0.710 kg CO2 per kWh. Back it with the purchase invoice, a photo log, and electricity bills or a sub-meter reading for the lighting circuit. Lenders and verifiers trust measured kWh over nameplate maths.
What to keep
- Old and new fitting counts and wattage, with the supplier invoice.
- Operating hours per day and days per year.
- A month of sub-meter readings before and after, if you can fit one.
Common mistakes
- Using rated watts of the old lamps without driver losses.
- Ignoring hours cut by daylight or sensors, which add to the saving.
- Claiming the saving before the new lights run for a full month.
What Senseible does here
Senseible reads fuel invoices and electricity bills and applies IPCC 2006 factors and the CEA grid factor (0.710 kg CO2 per kWh), so you can compare Scope 1 and 2 before and after a change from the documents themselves.
Sources: CEA CO2 Baseline Database, Bureau of Energy Efficiency, GHG Protocol Corporate Standard
Last reviewed 2026-10-23.