Which Bureau of Energy Efficiency foundry motor report fits my unit: cupola blower, 10 horse power rotary furnace or 15 horse power rotary furnace?

Three Bureau of Energy Efficiency (BEE) foundry reports for Batala swap a 10 horse power (HP) cupola blower motor, a 10 HP rotary furnace motor and a 15 HP one for rupees (Rs) 0.52, 0.52 and 0.60 lakh. Printed paybacks are 3.43, 2.74 and 2.01 years. The same 10 HP motor pays back faster on the rotary furnace.

The three reports side by side

• Cupola blower, 10 HP (7.5 kilowatts, kW): old motor 80% efficient, new 90.1%. Measured 6.0 kW, which is 64% loading. New 5.33 kW. Saving 3,027 kilowatt hours (kWh) a year, Rs 15,133. Cost Rs 0.52 lakh. Payback 3.43 years. Carbon dioxide (CO2) 2.5 tonnes.
• Rotary furnace, 10 HP: 80% to 90.1%. Measured 7.50 kW, the full rating. New 6.66 kW. Saving 3,783 kWh, Rs 18,917. Cost Rs 0.52 lakh. Payback 2.74 years. CO2 3.10 tonnes.
• Rotary furnace, 15 HP: 80% to 91.0%. Measured 11 kW. New 9.67 kW, saving 1.33 kW. 5,984 kWh, Rs 0.30 lakh. Cost Rs 0.60 lakh. Payback 2.01 years. CO2 4.85 tonnes.
• All three run 15 hours a day for 300 days, which is 4,500 hours, price power at Rs 5 a kWh and need 6 to 8 hours of process downtime.

Same motor, different payback: it is the load

The cupola and the 10 HP rotary report price the same 7.5 kW, 90.1% motor at Rs 0.52 lakh. The only thing that differs is what the old motor is assumed to draw: 6.0 kW against 7.50. An efficiency gain from 80% to 90.1% saves 1 minus 80 / 90.1, about 11.2%, of the draw. That is 0.67 kW on the blower and 0.84 kW on the furnace, so 3,027 against 3,783 kWh a year.

The 15 HP report assumes 11 kW drawn, near the 11.2 kW rating of a 15 HP motor, and a higher new efficiency of 91.0%. That is why its payback is the shortest.

Printed figures that do not tie

• The cupola report says the motor runs at full load for most operating hours, while its own Annexure 2 gives loading of 64%.
• The 10 HP rotary report prints a payback of 2.74 years in its summary and 2.85 in Annexure 2. Rs 0.52 lakh over its own Rs 18,917 saving is 2.75 years.
• Both 10 HP reports start each calculation from a round 80% old efficiency and use the same 90.1% new one, so the efficiency gain is an assumption, not a reading from the unit's own motor.
• The reports print CO2 of 2.5, 3.10 and 4.85 tonnes, about 0.81 to 0.83 kilograms (kg) a kWh. At the grid factor of 0.675 kg CO2 a kWh for financial year (FY) 2025-26, the same savings are about 2.0, 2.6 and 4.0 tonnes.

Before you order

• Read the motor's real draw on a normal heat, not the nameplate. The cupola report's 64% and the rotary report's 100% show how far two units of the same size can sit apart.
• Check how long the blower or rotary actually runs. All three reports use 15 hours a day. The reports say grid power in Batala is available for at most 12 to 14 hours a day, so a unit may run fewer motor hours.
• Ask the maker for the guaranteed efficiency at your load. A part-loaded motor loses efficiency.

The cupola blower report, line by line

• Old motor draws 6.0 kW at 80%. New draw: 6.0 x 80 / 90.1 = 5.33 kW. Saving 0.67 kW
• 0.67 kW x 15 hours x 300 days = 3,027 kWh x Rs 5 = Rs 15,133
• Rs 0.52 lakh / Rs 15,133 = 3.43 years, as printed
• My reading: the same motor on the rotary furnace's 7.50 kW draw saves 0.84 kW, 3,783 kWh and Rs 18,917, which is 2.75 years

First three lines are the report's own. The last is an example of my own reading, using the other report's figures.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so the units your foundry used each month are on file to test a report's hours against. A bill covers the whole unit, not one motor, so the motor's draw still needs a meter reading. The green loan check shows what a lender asks for.

• Green loan readiness check
• Medium and mains frequency induction furnace
• Foundry eco ventilators replacing exhaust fans
• Batala foundry cupola coke per tonne

Sources: BEE, Detailed project report: energy efficient motor for blower in cupola furnace, 10 HP, Batala, Jalandhar and Ludhiana foundry cluster (SAMEEEKSHA), BEE, Detailed project report: energy efficient motor in rotary furnace, 10 HP, Batala, Jalandhar and Ludhiana foundry cluster (SAMEEEKSHA), BEE, Detailed project report: energy efficient motor in rotary furnace, 15 HP, Batala, Jalandhar and Ludhiana foundry cluster (SAMEEEKSHA), Central Electricity Authority (CEA), CO2 Baseline Database for the Indian Power Sector

Last reviewed 2026-11-05. Report figures are from BEE's Small and Medium Enterprises (SME) programme project reports of 2011, at a Rs 5 a kWh tariff. Check today's tariff, a current quote and your own motor readings before you rely on the payback.