What does one screw compressor save an Alwar oil mill over four reciprocating ones?

In a Bureau of Energy Efficiency (BEE) report, one screw compressor (203 cubic feet per minute, 30 kilowatts) replaces four reciprocating ones (200, 42 kilowatts): 12 kilowatts less, 95,040 kilowatt hours (kWh) a year, Rs 4.56 lakh, for Rs 7.50 lakh. Its opening page says Rs 1.52 lakh.

The two sizes in the study

• Larger: four reciprocating compressors of 100, 50 and two of 25 cubic feet per minute (CFM), 200 CFM and 42 kilowatts (kW) in all, replaced by one 203 CFM screw machine at 7.5 bar and 30 kW. Saving 12 kW; cost Rs 7.50 lakh; Rs 4.56 lakh a year.
• Smaller: four 25 CFM machines (100 CFM, 24 kW) replaced by one 116 CFM machine at 18 kW. Saving 6 kW, 47,520 kilowatt hours (kWh), Rs 2.28 lakh a year on Rs 5.25 lakh, payback 2.30 years.

The sum behind it

Both reports run the compressors 24 hours a day for 330 days at Rs 4.80 a kWh, using rated kW, not metered load. For the larger one that is 12 kW x 24 hours x 330 days = 95,040 kWh, and x Rs 4.80 = Rs 4,56,192.

One figure that depends on hours

The larger report's opening page says the electricity bill falls by Rs 1.52 lakh a year. That is exactly 4.56 / 3, the saving at 8 running hours a day instead of 24. Its own sum, summary table and monetary benefit section use 24 hours and give Rs 4.56 lakh. Use your own running hours, read from the compressor controller, and check with a meter.

Its payback is 1.8 years in the summary and 20 months in the annexure, while Rs 7.50 lakh divided by Rs 4.56 lakh is 1.64 years.

What the saving is worth in carbon dioxide (estimate)

• Larger: 95,040 kWh x 0.675 = 64.2 tonnes carbon dioxide (CO2) a year; the report gives no CO2 figure
• Smaller: 47,520 kWh x 0.675 = 32.1 tonnes; the report says 38.49 tonnes
• Power per CFM: 42 / 200 = 0.21 kW falls to 30 / 203 = 0.148 kW

Report figures from the Bureau of Energy Efficiency (BEE) Alwar oil mill cluster project reports. CO2 uses the Central Electricity Authority (CEA) financial year 2025-26 grid factor, an estimate.

What Senseible does here

Senseible reads electricity bills into monthly kilowatt hours (kWh) and carbon dioxide equivalent (CO2e) at the Central Electricity Authority (CEA) factor for the bill's year, so the months before and after the new compressor can be compared on your own bills. The green loan check shows what a lender asks for.

• Green loan readiness check
• Alwar mustard oil mills: electricity per quintal
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• BEE star rating for air compressors

Sources: BEE, Detailed project report: screw compressor in place of reciprocating compressors, Alwar oil mill cluster (203 CFM) (SAMEEEKSHA), BEE, Detailed project report: screw compressor in place of reciprocating compressors, Alwar oil mill cluster (116 CFM) (SAMEEEKSHA), CEA, CO2 Baseline Database for the Indian Power Sector

Last reviewed 2026-11-04. Report figures are from a Bureau of Energy Efficiency (BEE) Small and Medium Enterprises (SME) programme project report; costs and paybacks are at the report year's prices. Check today's prices and a current quote before you rely on the payback.