Why does the Bureau of Energy Efficiency Godavari crusher motor report pay back in 1.38 years when the brick press motor of the same size takes 1.96?

Three Bureau of Energy Efficiency (BEE) Godavari reports replace a ball mill, brick press or crusher motor. The 10 horse power (HP) press and crusher motors both cost rupees (Rs) 0.206 lakh but pay back in 1.96 and 1.38 years, because the crusher report runs its motor 8,400 hours a year against 4,200.

The three reports side by side

• Ball mill, 20 HP: old motor 84% efficient, new 91.8%. Measured draw 14.62 kilowatts (kW), 14 hours a day for 350 days, which is 4,900 hours. Saving 6,087 kilowatt hours (kWh) a year, Rs 0.23 lakh. Cost Rs 0.455 lakh. Payback 1.99 years. Internal rate of return (IRR) 30.65%.
• Brick press, 10 HP: 80% to 90%. Measured 6.0 kW, 12 hours for 350 days, 4,200 hours. Saving 2,800 kWh, Rs 0.11 lakh. Cost Rs 0.206 lakh. Payback 1.96 years. IRR 31.37%.
• Crusher, 10 HP: 84% to 90%. Measured 7.10 kW, 24 hours for 350 days, 8,400 hours. Saving 3,976 kWh, Rs 0.15 lakh. Cost Rs 0.206 lakh (motor 0.201 plus 0.005). Payback 1.38 years. IRR 52.76%.
• All three price power at Rs 3.75 a kWh and call for about a day of process downtime.

Same motor cost, different payback: it is the hours

Each report follows the same formula: new draw = old draw x old efficiency / new efficiency, then saving x hours. Per running hour the crusher saves the least, 0.473 kW against 0.667 for the brick press and 1.242 for the ball mill. It wins on payback because the report runs it 8,400 hours, twice the press.

Per rupee spent, saving a year over cost is 50% for the ball mill (Rs 22,826 over Rs 45,500), 51% for the press (Rs 10,500 over Rs 20,600) and 72% for the crusher (Rs 14,910 over Rs 20,600).

Printed figures to treat with care

• The crusher report's own introduction says crushers in refractory units run about 10 to 12 hours a day, and then its baseline runs this motor 24 hours a day. My own arithmetic at 12 hours: 0.473 x 12 x 350 = about 1,990 kWh, Rs 7,450 at Rs 3.75, and Rs 0.206 lakh / Rs 7,450 is about 2.8 years, not 1.38.
• The ball mill report names crusher motors in its section on operating efficiency, giving a nameplate of 86%, while its own specification says 84% and its calculation uses 84%. It says the existing range is 84 to 86%; the brick press report says 80 to 82%.
• Carbon dioxide (CO2): the reports print 5, 2 and 3 tonnes a year and no factor. At the grid factor of 0.675 kilograms (kg) CO2 a kWh for financial year (FY) 2025-26, the savings are about 4.1, 1.9 and 2.7 tonnes.
• Savings are a small share of the draw: 8.5% for the ball mill, 11.1% for the press and 6.7% for the crusher.

Before you order

• Count the hours your crusher really runs. At 10 to 12 hours it pays back in more than twice the printed time.
• Meter the motor's draw on a normal shift. The saving is a few percent of that figure.
• Ask the supplier for the guaranteed efficiency at your load, since a lightly loaded ball mill or crusher motor sits below its full-load figure.

The crusher report as printed, then at 12 hours

• Draw 7.10 kW x 84 / 90 = 6.63 kW. Saving 0.473 kW
• 0.473 x 24 hours x 350 days = 3,976 kWh x Rs 3.75 = Rs 14,910. Rs 0.206 lakh / 0.15 lakh = 1.38 years
• My reading at 12 hours: 0.473 x 12 x 350 = 1,987 kWh x Rs 3.75 = Rs 7,452
• Rs 0.206 lakh / Rs 7,452 = about 2.8 years

First two lines are the report's own. The last two are an example of my own reading, using the report's inputs.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so your monthly units are on file next to a report's yearly kWh. A bill covers the whole plant, so the motor's own draw still needs a meter. The green loan check shows what a lender asks for.

• Green loan readiness check
• Six Godavari kiln gasifier reports compared
• Godavari tunnel kiln reports compared
• Heat recovery on a 100 tonne refractory kiln

Sources: BEE, Detailed project report: energy efficient motor for ball mills 20 HP, East and West Godavari refractories cluster (SAMEEEKSHA), BEE, Detailed project report: energy efficient motor for brick press 10 HP, East and West Godavari refractories cluster (SAMEEEKSHA), BEE, Detailed project report: energy efficient motor for crushers 10 HP, East and West Godavari refractories 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 2010, at a Rs 3.75 a kWh tariff. Check today's tariff, a current quote and your own motor readings before you rely on the payback.