How much fuel and electricity does a coir yarn dyeing unit use per tonne?
In the BEE study of Alleppey, a 450 tonne a year dyeing unit used 4,42,920 kWh and 3,71,250 litres of fuel: about 984 kWh and 825 litres per tonne of yarn. A 400 tonne unit used about 737 kWh and 504 litres. Fuel is roughly nine tenths of the energy.
Two dyeing units, side by side
- 450 t a year: 4,42,920 kWh and 3,71,250 litres of fuel, 409 toe in all.
- 400 t a year: 2,94,804 kWh and 2,01,600 litres, 227 toe.
- Per tonne: 984 kWh and 825 litres against 737 kWh and 504 litres. The bigger unit uses more of both per tonne, so size alone does not make a dyer efficient.
- Fuel is 91% of the energy in the first unit and 89% in the second; electricity runs pumps, fans, hydro extractors and spoolers.
Where the heat goes
Yarn is soaked in hot water and bleach, dyed in vats at a liquor ratio of about 1:8 to 1:10, spun dry in hydro extractors and sun dried. Bleach water is often heated on open chulhas; dye baths on thermic fluid heaters or boilers fired with firewood, coconut husk, furnace oil or diesel. Drained water leaves at 80 to 90 C, and each batch takes about four hot washes.
Check this before you quote a figure
- Write down each fuel separately. The study counts every fuel in litres at 10,000 kcal each, which only fits oil, so its fuel line cannot tell you how much was wood or husk.
- The study's summary table gives dyeing 0.15 kWh per kg. Its own unit figures work out near 0.74 to 0.98 kWh per kg. Use your meter, not the summary.
- Divide by tonnes of yarn dyed, not tonnes bought, and note how much was bleached only.
The savings the study priced
- VFDs on heater fans, oil pumps, dye vat pumps and dryer blowers: 1,24,675 kWh a year in its example, a 7 month payback.
- Recovering heat from drained dye water: 42 t of wood a year for two 500 kg machines, a 42 month payback.
- Flue heat recovery on a wood fired heater, 220 C to 130 C: 64.8 t of wood a year, a 6 month payback.
- Improved chulhas for bleach water, paid back in under 6 months.
450 tonne dyeing unit, CO2 a year (estimate)
- Electricity: 4,42,920 kWh x 0.675 kg = 299 t
- If all 3,71,250 litres were furnace oil: x 2.97 kg = 1,103 t
- All oil: 1,402 t, about 3.1 t per tonne of yarn
- All wood or husk: 299 t fossil, about 0.66 t per tonne, with the fuel's CO2 reported as biogenic
Unit energy from the BEE SME Program study of the Alleppey coir cluster. The study does not split the fuel by type, so the two cases bracket a real unit. Grid factor CEA FY 2025-26; furnace oil 2.97 kg CO2 per litre.
What Senseible does here
Senseible reads your KSEB bills and furnace oil or diesel invoices into monthly fossil CO2 per tonne of yarn. It holds no factor for firewood or husk; keep those weights in your register and report them as biogenic.
Sources: BEE SME Program, Alleppey coir cluster study (SAMEEEKSHA), CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0
Last reviewed 2026-11-01.