# How many kWh per tonne of saleable castings does an induction foundry use at 300, 850 and 2,400 tonnes a year?

Canonical: https://senseible.earth/answers/induction-foundry-kwh-per-tonne-by-size

In TERI's Shivamogga profile, a foundry shipping 300 t of castings a year uses 600,000 kWh, 2,000 kWh a tonne; 850 t uses 1.4 million kWh, about 1,650; and 2,400 t uses 3.3 million kWh, 1,375. That is two to three times the furnace's 600 to 850 kWh per tonne melted.

## Three sizes of foundry

- About 25 t a month, 300 t a year: 600,000 kWh, no LPG, 51.6 toe. 2,000 kWh per tonne shipped.
- About 70 t a month, 850 t a year: 1.4 million kWh and 10 t LPG, 132.9 toe. 1,647 kWh per tonne.
- About 200 t a month, 2,400 t a year: 3.3 million kWh and 20 t LPG, 308.8 toe. 1,375 kWh per tonne.
- These match the cluster's own C, B and A categories; most Shivamogga units are B.

## Why per tonne shipped is far above the furnace figure

TERI gives melting at 600 to 750 kWh per tonne of molten iron and 700 to 850 for steel. That is per tonne melted. Runners, risers and rejects go back into the furnace, so you melt far more than you ship; sand plant, compressors, cooling pumps, core ovens and fettling add the rest. Fixed loads such as compressors, pumps and lighting are spread over fewer tonnes in a small unit, one reason 300 t a year takes 45% more power per tonne than 2,400 t.

## Work out your own yield from the bill

1. Take a year's kWh and multiply by 0.75 to 0.80, TERI's share for melting.
2. Divide by your furnace's kWh per tonne melted, from its own meter or the 650 mid range.
3. Divide tonnes shipped by tonnes melted: that is your yield.
4. A low yield points to gating design and rejects, which cost power before any furnace does.

## Levers that change the number

- Cut rejections from about 10% toward 5%.
- IGBT furnace: about 550 kWh per tonne melted against 750 or more for old SCR furnaces.
- A furnace lid recovers about 6% of input.
- Shot blast runners and risers before remelting.

## 2,400 t a year foundry, yield and CO2 (estimate)

- Melting power: 3.3 million kWh x 0.75 to 0.80 = 2.48 to 2.64 million kWh
- At 650 kWh per tonne melted: 3,808 to 4,062 t melted to ship 2,400 t, a yield near 59 to 63%
- CO2: 3.3 million kWh x 0.675 = 2,228 t + 20 t LPG x 2.98 = 60 t; 2,287 t, or 0.95 t per tonne shipped
- Same sums for 300 t: 1.35 t per tonne; for 850 t: 1.15 t

Unit energy and melting ranges from TERI's cluster profile of Shimoga foundry industries (the table there is headed cupola based, but every Shimoga unit melts by induction). The 650 kWh figure is the midpoint of TERI's iron range. CEA FY 2025-26 grid factor; LPG 2.98 kg CO2 per kg.

## What Senseible does here

Senseible reads your monthly power bills and LPG invoices into CO2 per tonne shipped, so the yield and kWh trend show up month by month without a spreadsheet.

- [Your MSME carbon number](https://senseible.earth/msme-carbon-number)
- [Shivamogga foundries energy and CO2](https://senseible.earth/answers/shivamogga-foundry-cluster-energy-and-co2)
- [Induction furnace kWh per tonne benchmark](https://senseible.earth/answers/induction-furnace-kwh-per-tonne-benchmark)
- [Foundry footprint per good casting](https://senseible.earth/answers/foundry-carbon-footprint-per-tonne-good-casting)

Sources: [TERI, Cluster profile: Shimoga foundry industries (SAMEEEKSHA)](https://sameeeksha.org/pdf/clusterprofile/Shimoga-Foundries-Karnataka.pdf), [CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0](https://cea.nic.in/cdm-co2-baseline-view?mappingId=234&lang=en)

Last reviewed 2026-11-01.