How can electricity be about 4% of a Tiruppur dye house's energy but 22% of its energy cost?

In the Bureau of Energy Efficiency (BEE) Tiruppur manual a dye house uses 0.71 kilowatt hours (kWh) and 4.0 kilograms (kg) of fuel for each kg dyed. Power is 3.9% of the energy but rupees (Rs) 3.3 of Rs 15.3 of cost, 21.6%, because a kWh costs about seven times as much per unit of heat.

The manual's per kilogram table

• Dyeing: 0.71 kWh and 4.0 kg of fuel a kg; electricity Rs 3.3, thermal Rs 12, total Rs 15.3 a kg.
• Compacting: 0.05 kWh and 0.38 kg of fuel; electricity Rs 0.23, thermal Rs 1.14, total Rs 1.37.
• Knitting: 0.26 kWh, Rs 1.2. Computer embroidery: 0.12 kWh, Rs 0.56. Both are electricity only.

Energy share and cost share

The factor that fits the manual's tables is 860 kilocalories (kcal) a kWh (878 lakh kcal for 102,128 kWh); the manual does not print it as a factor. Its fuel table gives firewood 3,800 kcal a kg. Dyeing: 0.71 x 860 = 611 kcal of power against 4.0 x 3,800 = 15,200 kcal of fuel, so power is 611 / 15,811 = 3.9% of the energy. The manual's own sample dye houses agree: power is 4,831 of 125,215 lakh kcal (1 lakh = 100,000), 3.9%, and 878 of 42,478, 2.1%.

Cost tells a different story: 3.3 / 15.3 = 21.6%. Compacting is the same shape: 2.9% of energy, 0.23 / 1.37 = 16.8% of cost.

Where the gap comes from

Power in the table costs about Rs 4.6 a kWh in every row (3.3 / 0.71 = 4.65; 0.23 / 0.05 = 4.6; 0.56 / 0.12 = 4.67; 1.2 / 0.26 = 4.62). Fuel costs Rs 3 a kg (12 / 4.0 and 1.14 / 0.38), the firewood price. Per 1,000 kcal that is Rs 5.41 for power and Rs 0.79 for firewood, 6.9 times.

So a 10% cut in power is worth about 2.2% of the dye house's energy bill, and a 10% cut in wood about 7.8%. In tonnes the order flips again: the grid line carries the factor, 0.71 x 0.675 = 0.479 kg of carbon dioxide (CO2) a kg dyed at 0.675 kg a kWh for financial year (FY) 2025-26, while wood is counted separately.

Which saving to chase

• For rupees: fuel first in a dye house. For the grid line in a carbon figure: power.
• Electricity-only units (knitting, embroidery) have no fuel line, so power is all of both.
• Prices are from the manual, dated 2011. Redo the split from your own invoices: rupees for each energy form over the year.

One kilogram dyed, power against fuel

• Power: 0.71 kWh x 860 = 611 kcal; Rs 3.3
• Fuel: 4.0 kg x 3,800 = 15,200 kcal; Rs 12
• Energy share of power: 611 / 15,811 = 3.9%; cost share: 3.3 / 15.3 = 21.6%
• Cost of 1,000 kcal: power 4.65 / 0.86 = Rs 5.41; firewood 3 / 3.8 = Rs 0.79
• 10% saving: power 0.1 x 3.3 = Rs 0.33 (2.2% of 15.3); wood 0.1 x 12 = Rs 1.20 (7.8%)

Inputs are the manual's tables, dated 2011. The shares and the 10% case are our arithmetic.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so power and fuel are on file side by side in rupees and units, so your split is your own. It does not allocate cost to machines; that needs sub-meters.

• Tiruppur fuels and buyer carbon data
• Cotton and polyester dyeing energy per kg
• Green loan readiness check

Sources: BEE, Manual on Energy Conservation Measures in Textile Cluster, Tirupur (SAMEEEKSHA), CEA CO2 Baseline Database, version 22.0

Last reviewed 2026-11-06. Prices and unit use are from BEE's manual, dated 2011; redo the split with your own current invoices.