# Where does the energy go in a tannery: drying, hot water, space heating or machines?

Canonical: https://senseible.earth/answers/tannery-energy-split-drying-hot-water-heating

The European Commission's tanning reference document puts about 85% of a tannery's energy as heat and 15% as electricity. Drying and hot water take 32 to 34% each, space heating 17 to 20%, and machines and process vessels 9 to 12%. Those figures come from studies made in the 1970s and 1980s.

## The split the reference document prints

- Heat is about 85% of a tannery's energy and electricity about 15%. The document says this follows from studies made in the 1970s and 1980s.
- Heat: drying 32 to 34%, hot water 32 to 34%, space heating 17 to 20%.
- Electricity: machinery and process vessels 9 to 12%, pressurised air 1.5 to 3%, light 1.5 to 3%.
- Boilers generally run on gas, oil or coal, and sometimes on waste such as fat, tallow and pallets. Most tanneries use electricity from the public supply.

## Where the document differs from itself

The table gives drying 32 to 34%. In its description of drying, the same document says drying is one of the most energy intensive processes and may account for up to 45% of total energy consumption. Treat 32 to 34% as the table's share and 45% as the upper case it mentions. It does not say which tanneries reach 45%.

## What this means for your records (my reading)

This is my reading, not the document's. Boiler fuel for drying, hot water and space heating is Scope 1 and shows on fuel invoices. Electricity for drums, pumps, compressors and light is Scope 2 and shows on the electricity bill. So a tannery's fuel lines should be several times its electricity line once both are in the same unit. If yours are not, check whether a fuel invoice is missing or a boiler is running on steam bought from outside.

## Why your split may differ

The document says climate has a decisive influence and that a tannery's thermal need is thought to fall by 2% for each degree the annual average temperature rises. It gives no Indian split. Compare your own months with each other first, then with this table as a rough guide.

## Example month: does your split look like 85 to 15?

- Electricity bill: 40,000 kilowatt hours (kWh) x 3.6 = 144,000 megajoules (MJ) = 144 gigajoules (GJ)
- For electricity to be 15% of the total, heat would be 144 / 0.15 x 0.85 = 816 GJ, so a total of 960 GJ
- Electricity emissions: 40,000 x 0.675 kilograms of carbon dioxide (CO2) per kWh for financial year (FY) 2025-26 = 27,000 kilograms (kg), or 27.0 tonnes
- If your fuel invoices convert to far less than 816 GJ, look for a missing invoice before you conclude the tannery is efficient

The 40,000 kWh is an example. 1 kWh = 3.6 MJ. Convert fuel to GJ with the fuel's calorific value from your supplier or the Intergovernmental Panel on Climate Change (IPCC) defaults.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into records by billing period. It does not split a bill between drying, hot water and machines; that needs your own meters.

- [Leather Working Group energy and carbon data](https://senseible.earth/answers/leather-working-group-audit-energy-carbon)
- [Ambur tannery boiler and effluent plant emissions](https://senseible.earth/answers/ambur-tannery-boiler-etp-emissions)
- [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), [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard)

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.