How much does a VFD on a 10 HP jet dyeing machine pump save?
About 0.83 kW per pump, 15% of a throttled 10 HP circulation pump drawing 5.5 kW, in BEE's Surat report: 34,860 kWh a year across five jet machines running round the clock. Cost Rs 1.62 lakh, saving Rs 1.95 lakh at Rs 5.60 a kWh, payback about 10 months (2010).
The pumps in the report
- 150 kg jet machines dyeing at 130 C, each with a 7.5 kW (10 HP) pump rated 50 m3 an hour at 25 m head.
- Flow set by a throttling valve, 24 hours a day, 350 days a year.
- Measured in three units: 664, 855 and 635 kWh a day for sets of 5, 6 and 5 pumps, about 5.3 to 5.9 kW a pump.
- The audits found about 40% of pumps in the cluster throttled or moving more liquor than needed.
The arithmetic
- 5.5 kW x 15% = 0.83 kW a pump; 4.15 kW for five.
- 4.15 kW x 24 hours x 350 days = 34,860 kWh x Rs 5.60 = Rs 1.95 lakh.
- Cost: Rs 0.27 lakh a drive with panel and cabling, Rs 1.37 lakh for five, plus Rs 0.25 lakh fitting: Rs 1.62 lakh.
- Payback 0.83 years; one day of downtime.
15% is an assumption, so test it
The report assumes the cut rather than measuring it. By the cube law it quotes, 15% less power needs only about 5% less pump speed. Log kW on one pump, fit one drive, and run a trial batch at the lower speed to check fabric movement and shade before you buy the rest.
The CO2 figure
34,860 kWh x 0.675 = 23.5 t of CO2 a year on today's grid. The report's 30 t used an older factor.
Five pumps, one year
- Saved: 5 x 0.83 kW = 4.15 kW
- 4.15 kW x 24 h x 350 days = 34,860 kWh
- 34,860 x Rs 5.60 = Rs 1.95 lakh; payback 1.62 / 1.95 = 0.83 years
- CO2: 34,860 x 0.675 = 23.5 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 about 2,900 kWh a month less shows against last year. For a quick figure, the free electricity bill calculator turns kWh saved into CO2.
- Free carbon calculators
- VFD savings on pumps and fans
- Surat processing house fuel per metre
- Surat processing units: buyer carbon data
- Thermopac pump VFD
Sources: BEE, Detailed project report: VFD for jet machine pump (10 HP), Surat 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.