Why do the Bureau of Energy Efficiency (BEE) Odisha sponge iron reports for 25, 40 and 60 horsepower crusher motors print three different carbon dioxide (CO2) factors?

BEE's Odisha sponge iron reports swap a rewound crusher motor for a 92 to 94% efficient one, saving 6,814, 12,040 and 21,073 kilowatt hours (kWh) a year, for motors costing rupees (Rs) 0.65, 1.11 and 1.79 lakh. Payback is about 2.2 to 2.4 years, printed as months. The CO2 lines imply 1.76, 1.16 and 0.76 kilograms a kWh.

The three reports side by side

• 25 horsepower (HP), kilns of 50 and 100 tonnes a day: the audited motor draws 19.89 kilowatts (kW) for 12 hours a day. The new motor, 92.2% efficient, draws 18.27 kW, a saving of 1.62 kW (8%). About 1.62 x 12 x 350 days = 6,804 kWh; the report prints 6,814, which uses the unrounded 1.6224 kW. Rs 3.90 a kWh gives Rs 0.27 lakh. Cost Rs 0.65 lakh, Rs 0.66 lakh with panel and cabling.
• 40 HP, a 150 tonne a day kiln: 30.96 kW for 8 hours. New motor 92.9% efficient draws 26.66 kW, saving 4.30 kW (14%). 4.30 x 8 x 350 = 12,040 kWh. Rs 0.47 lakh. Cost Rs 1.11 lakh, Rs 1.12 lakh with panel.
• 60 HP, a 400 tonne a day kiln: 51.47 kW for 8 hours. New motor 93.7% efficient draws 43.95 kW, saving 7.53 kW (15%). About 7.53 x 8 x 350 = 21,084 kWh; the report prints 21,073, which uses the unrounded 7.526 kW. Rs 0.82 lakh. Cost Rs 1.79 lakh, Rs 1.80 lakh with panel.
• Printed indicators, 25, 40 and 60 HP: internal rate of return (IRR) 21.49%, 23.26% and 27.19%; net present value (NPV) Rs 0.22, 0.42 and 0.90 lakh; two days of downtime each.

The payback is in years, not months

The summary tables print 2.45, 2.36 and 2.18 under a "Months" heading. The sums say years: Rs 0.65 lakh / Rs 0.27 lakh is 2.4 years, Rs 1.11 / 0.47 is 2.4 and Rs 1.79 / 0.82 is 2.2. The 25 and 60 HP texts agree, "Two Year & Four Months" and "Two Years Two Months". The 40 HP text says "One Year Eight Months", which fits neither its 2.36 nor its own cost and benefit.

Three CO2 factors in three reports

The reports print 12, 14 and 16 tonnes a year and give no factor. Divided by the kWh saved, that is 1.76, 1.16 and 0.76 tonnes a megawatt hour. They cannot all be right for the same grid. At the Central Electricity Authority (CEA) factor for financial year (FY) 2025-26, 0.675 kilograms a kWh, the same kWh give 4.6, 8.1 and 14.2 tonnes. This is Scope 2, grid power not bought.

Other printed figures that do not tie

• The text says a rewound motor runs at about 85%. The annexes use 86% for the 25 HP and 80% for the 40 and 60 HP. The 40 HP specification lists the new motor at 92.7% and the rest of the report at 92.9%.
• The summaries print 0.65, 1.11 and 1.79 lakh for the project; the cost tables total 0.66, 1.12 and 1.80 with the 0.01 for panel and cabling. The 40 HP summary says 12,042 kWh and its text and annexure 12,040.
• The 25 HP annexure gives a draw of 19.89 kW at 86% on a 90.31% load. Our check: 18.65 kW rated x 90.31% = 16.84 kW out; at 86% that is 19.58 kW in, not 19.89. The difference is small.

What to take from it

• The gain is real but modest: 8 to 15% of the motor's draw, Rs 0.27 to 0.82 lakh a year.
• The saving scales with hours and load: the 25 HP case runs 12 hours, the others 8.
• Measure your motor's kW with a clamp meter for a day. Compare it with the report's draw before you take its saving.

The 40 HP report, rebuilt

• Draw before: 30.96 kW. New motor: 29.84 kW rated x 83% load / 92.9% = 26.66 kW
• Saving: 30.96 less 26.66 = 4.30 kW x 8 hours x 350 days = 12,040 kWh
• Money: 12,040 x Rs 3.90 = Rs 46,956, printed Rs 0.47 lakh
• Payback: Rs 1.11 lakh / Rs 0.47 lakh = 2.4 years (not months)
• CO2 at 0.675: 12,040 x 0.675 = 8.1 tonnes, against 14 printed

Printed lines are the report's own at the report year's prices. The 0.675 is the CEA version 22.0 grid factor for FY 2025-26, an estimate of today's saving.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so your kiln's power by month is on file. It cannot split one motor out of the bill; use a clamp reading for that.

• Sponge iron cooler pump saving check
• Sponge iron waste heat power, 2 and 4 megawatt
• Old report CO2 versus today's grid factor
• Green loan readiness check

Sources: BEE, Detailed project report: energy efficient motor, crusher section, 25 HP, Orissa sponge iron cluster (SAMEEEKSHA), BEE, Detailed project report: energy efficient motor, crusher section, 40 HP, Orissa sponge iron cluster (SAMEEEKSHA), BEE, Detailed project report: energy efficient motor, crusher section, 60 HP, Orissa sponge iron 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, with electricity at Rs 3.90 a kWh. Check your tariff, your motor's measured kW and a current quote before you rely on the payback.