How do I work out electricity carbon per carat for an HPHT diamond press?
Meter each press, add the kWh for every growth run in a month, multiply by your grid factor and divide by rough carats grown. HPHT presses run hot and long, so electricity dominates; use metered runs, not nameplate ratings.
The calculation
- kWh per press per month from sub meters.
- Multiply by 0.710 kg CO2 per kWh, or by the factor for your supply if you buy green power with valid attributes.
- Divide by rough carats grown, then by the cutting yield if a buyer wants per polished carat.
Common mistakes
Using press rating times hours overstates use when presses cycle; ignoring chillers and compressors understates it. Meter the plant auxiliaries and share them by run hours.
Claims
A low carbon claim needs the electricity contract and meter data behind it. Without them, the grid factor applies.
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.
- CVD grower electricity per carat
- Lab grown diamond per carat
- Can lab grown diamonds be called sustainable?
Sources: CEA CO2 Baseline Database for the Indian Power Sector, GHG Protocol Scope 2 Guidance, GHG Protocol Corporate Standard
Last reviewed 2026-10-21.