How much electricity does stenter blower speed optimisation save?

About 72,000 kWh a year per stenter in BEE's Pali report, from running the four fans in the last two chambers slow: 4.2 kW down to 1.7 kW each. Many stenters already have VFDs used only as soft starters. Cost Rs 2.60 lakh, payback about 9.4 months at 2010 prices.

The stenter in the report

• Five chambers, ten fans of 7.5 HP (5.6 kW), each drawing 4.2 kW at high speed.
• A stenter uses 40 to 55 kWh of power and 50 to 60 kg of pet coke an hour.
• Pali has over 100 stenters.

Why the last two chambers

Drying is fastest at an air jet of about 32 feet a second (9.8 m a second); faster air adds nothing. The fourth and fifth chambers only hold the fabric at heat-setting temperature, so air speed matters little there. In one audited unit the fifth chamber's fan had been removed and the stenter still ran at the same speed.

Check what you already own

1. Two-speed fan motors: switch chambers four and five to slow. No capital needed.
2. VFDs already fitted: the report found them used only to soften starting. Set a lower speed on the last two chambers.
3. Neither: five 12 kW VFDs, each running two fans, Rs 2.50 lakh plus Rs 0.10 lakh fitting and about a week's shutdown.
4. Run the same quality before and after and check heat-set results; the report gives no trial data.

Money and CO2

4 fans x 2.5 kW = 10 kW, x 24 hours x 300 days = 72,000 kWh. At Rs 4.60 a kWh, Rs 3.31 lakh, against Rs 2.60 lakh: 0.79 years. On today's grid that is 48.6 t of CO2 a year, not the report's 64 t.

One stenter, one year

• Saved per fan: 4.2 minus 1.7 = 2.5 kW
• 4 fans x 2.5 kW x 24 h x 300 days = 72,000 kWh
• 72,000 x Rs 4.60 = Rs 3.31 lakh
• CO2: 72,000 x 0.675 = 48.6 t

Grid at CEA's FY 2025-26 factor, an estimate.

What Senseible does here

Senseible reads electricity bills into monthly kWh and CO2, each linked to its bill, so 6,000 kWh a month less shows against last year. If you need to buy drives, the green loan check shows what a lender will ask.

• Green loan readiness check
• Stenter fuel and CO2 per metre
• Stenter waste heat recovery
• Thermopac pump VFD
• Stenter fabric temperature control

Sources: BEE, Detailed project report: blower speed optimisation in stenter, Pali textile cluster (2010, SAMEEEKSHA), CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0 (FY 2025-26 grid factor)

Last reviewed 2026-11-01. Report figures are from a BEE SME programme project report; costs and paybacks are at the report year's prices. Check today's fuel and power prices and a current quote before you rely on the payback.