What do Coimbatore foundries use per tonne of castings, and how does one unit compare with the cluster?

Between 1,000 and 1,200 kWh per tonne of good castings, 600 to 700 of it in melting, is what TERI measured in Coimbatore's induction foundries. A 1,000 tonne a year unit uses about 1.1 million kWh, about 743 t CO2. Above 1,200, look at your furnace and your rejections first.

The cluster you are measured against

• About 535 foundries: about 15 large, 70 medium, the rest small and micro, making about 2,000 tonnes a day (about 0.6 million tonnes a year).
• Half make pump-set castings. The rest serve automotive (15%), wet grinders (10%), textile machinery (10%) and jobbing work (15%).
• In 2014 to 15 the cluster used 460 million kWh and 32,000 tonnes of coke, 58,640 tonnes of oil equivalent. That is about 407,000 tonnes of CO2 on today's factors.
• Power comes from the state utility or from wind farms in Tamil Nadu.

Check your own number

1. Add 12 months of kWh from your bills and divide by tonnes of good castings despatched.
2. Compare with 1,000 to 1,200 kWh a tonne. If you have a sub-meter, compare melting alone with 600 to 700 kWh per tonne of molten metal.
3. For a cupola, coke should be 10% to 15% of metal melted, or 15% to 20% of good castings.
4. If you are high, check rejections (many units run at 6% to 9%), furnace age and whether the furnace has a lid.

Where the savings are

• An old induction furnace at 750 kWh or more per tonne of molten metal can be replaced with one near 550. TERI puts the payback under a year.
• A lid cuts radiation and convection loss, 4% to 6% of input energy.
• Bringing rejections below 5%, and shot blasting the sand off runners and risers before remelting, saves melting energy for little or no cost.
• Wind power bought under contract cuts market-based Scope 2, if you keep the supply records.

Why pump makers will ask you

Pump and motor makers who export are starting to ask their foundries for kg CO2 per tonne, because their own buyers want a product footprint. A green loan for a new furnace is easier to get with kWh per tonne before and after from bills.

Worked example: a 1,000 tonne a year induction foundry

• Electricity: 1,100,000 kWh x 0.675 = 742.5 t CO2, about 0.18% of the cluster's 407,000 t
• Per tonne of good castings: 742.5 / 1,000 = 0.74 t CO2
• New furnace, 750 down to 550 kWh per tonne of molten metal, on 1,400 t melted: 200 x 1,400 = 280,000 kWh saved
• CO2 saved: 280,000 x 0.675 = 189 t a year

Unit energy is from TERI's Coimbatore profile. 1,400 t melted assumes about 70% yield; use your own melt log. Grid factor for FY 2025-26; coke in the cluster total at 3.02 t CO2 per tonne (IPCC default).

What Senseible does here

Senseible reads your electricity bills and coke invoices into a monthly record, and the green loan check shows what a lender will look for before you apply for a furnace upgrade.

• Green loan readiness check
• Coimbatore induction foundry: CBAM vs footprint
• Coimbatore pump exporter EPD for buyers
• Foundry footprint per good casting

Sources: TERI, Cluster profile: Coimbatore foundries (SAMEEEKSHA), IPCC 2006 Guidelines, Volume 2 Energy, CEA CO2 Baseline Database, version 22.0

Last reviewed 2026-10-29. Cluster energy is for 2014 to 15. Update if a newer Coimbatore profile is published.