# Is my tannery's energy use per tonne of raw hide high or low against European figures?

Canonical: https://senseible.earth/answers/tannery-energy-per-tonne-raw-hide-european-range

The European tanning reference document says tannery energy ran from 9.3 to 42 gigajoules (GJ) per tonne of raw hide in one survey. Spanish tanneries in 1996 averaged 174.3 watt hours of electricity per square foot of finished leather. Use these as a rough range, not an Indian benchmark.

## The figures the document prints

- A survey of European tanneries: 9.3 to 42 GJ per tonne of raw hides. The document's input and output chart prints the same 9.3 to 42 GJ.
- Spanish tanneries, 1996 averages: fuel 80.2 grams per square foot of finished leather, electricity 174.3 watt hours per square foot, water 11.3 litres per square foot. The fuel line gives no fuel type.
- United Kingdom (UK) tanneries processing bovine hides: raw to wet blue 28.58 kilowatt hours (kWh) per tanned hide; tanned to finish 17.7 kWh per square metre of finished leather, with a printed range of 6.7 to 35.7.

## A printed figure that does not tie

For raw to wet blue, the document prints an average of 28.58 kWh per tanned hide beside a range of 29.78 to 31.39. An average cannot sit below the lowest value of its own range, so at least one of the three numbers is misprinted. The document does not say which. Do not quote the UK range for raw to wet blue.

## The Spanish figures in other units

- Electricity: 174.3 Wh = 0.1743 kWh per square foot. Times 10.764 square feet per square metre = 1.876 kWh per square metre.
- Water: 11.3 litres x 10.764 = 121.6 litres per square metre.
- Do not set 1.876 kWh against the UK 17.7 kWh. The Spanish line is electricity only, and the document does not say which energy the UK line counts.

## Why Indian tanneries should not copy the range

The document says climate has a decisive influence and that thermal need is thought to fall by 2% for each degree the annual average temperature rises. Its figures are from European tanneries, and it says they vary with climate and with tannery type and process. Use the range to spot a number that looks 10 times too high or too low, not to grade your tannery.

## How to put your own month in the same unit

1. Electricity: kWh on the bill x 3.6 = megajoules (MJ). Divide by 1,000 for GJ.
2. Fuel: kilograms or litres on the invoices x the fuel's net calorific value, in MJ. The Leather Working Group page here shows the conversion.
3. Add the two, then divide by tonnes of raw hide processed in the same month, weighed the same way every month (say whether salted or green weight, since the document's yield figures are for salted raw hide and its energy survey does not state the weight basis).

## Example month: 60 tonnes of raw hide

- Electricity: 30,000 kWh x 3.6 = 108,000 MJ = 108 GJ
- Fuel, converted from invoices: 900 GJ (an example figure)
- Total: 108 + 900 = 1,008 GJ. Per tonne: 1,008 / 60 = 16.8 GJ, inside the 9.3 to 42 range
- Electricity emissions: 30,000 x 0.675 kilograms of carbon dioxide (CO2) per kWh for financial year (FY) 2025-26 = 20,250 kilograms (kg)

All inputs are examples. Being inside a wide range says little; a month-on-month trend in your own GJ per tonne says more.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into records by billing period, so the kWh and fuel for each month are on file. You add the hide tonnes. It does not weigh hides or measure leather area.

- [Where a tannery's energy goes](https://senseible.earth/answers/tannery-energy-split-drying-hot-water-heating)
- [Leather Working Group energy and carbon data](https://senseible.earth/answers/leather-working-group-audit-energy-carbon)
- [Carbon footprint per square foot of leather](https://senseible.earth/answers/leather-tannery-carbon-footprint-per-square-foot)

Sources: [European Commission, Integrated Pollution Prevention and Control (IPPC) Reference Document on Best Available Techniques for the Tanning of Hides and Skins, February 2003 edition (filed by the publisher as superseded)](https://eippcb.jrc.ec.europa.eu/sites/default/files/2020-03/superseded_tan_bref-0203.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 2026-11-06. Figures are from the February 2003 edition of the European tanning reference document, which the publisher files as superseded; its energy and effluent tables rest on European tanneries and on older studies. Check the current edition and your own records before you quote a number to a buyer.