Why do the Bureau of Energy Efficiency Jodhpur insulation reports for 15, 30 and 50 tonne a day lime kilns print different savings for the same job?

Three Bureau of Energy Efficiency (BEE) Jodhpur reports price kiln insulation for 15, 30 and 50 tonne a day (tpd) lime kilns at rupees (Rs) 1.2, 2.4 and 3.4 lakh. Their bodies cut pet coke by 48, 100 and 140 tonnes a year, but each executive summary prints a different tonnage and rupee saving.

The three reports side by side

• 15 tpd: pet coke 1,200 tonnes a year down to 1,152, which is 48 tonnes. Saving printed as Rs 2.5 lakh in Table 3.1 and Rs 3.0 lakh in the text. Table 4.1 total Rs 1.2 lakh (1.0 + 0.1 + 0.1).
• 30 tpd: 2,400 down to 2,300, which is 100 tonnes. Saving printed as Rs 5.0 to 6.0 lakh in section 3.2 and Rs 6.0 to 7.0 lakh in section 4.3. Total Rs 2.4 lakh (2.0 + 0.2 + 0.2).
• 50 tpd: 4,000 down to 3,860, which is 140 tonnes. Saving printed as Rs 9.0 to 10.0 lakh. Total Rs 3.4 lakh (3.0 + 0.2 + 0.2).
• All three cost pet coke at Rs 7,000 a tonne, take the insulation as a repair of damaged areas, and credit no electricity or production gain.
• Executive summaries: 15 tpd prints 3% x 1,200 = 36 tonnes = Rs 2.5 lakh. 30 tpd prints 3.5% x 2,400 = 84 tonnes = Rs 5.5 lakh. 50 tpd prints 140 tonnes x Rs 7,000 = Rs 9.0 lakh. The 30 and 50 tpd summaries also carry a stray 'Fuel Consumption = 1200 MT/yr' line, and the 50 tpd one says 'Rs 5.5 Lakh per year'.

The three kilns burn the same pet coke per tonne a day

1,200 / 15, 2,400 / 30 and 4,000 / 50 all equal 80 tonnes of pet coke a year for each tonne a day of capacity. So the three reports are one job at three sizes, and the saving share is 4.0%, 4.2% and 3.5%. The texts print 'approximately 4%' for 15 tpd and '3 to 4%' for 30 tpd, and Table 3.1 in the 15 tpd report prints 3%.

Cost for each tonne a day is Rs 0.080 lakh at 15 and 30 tpd and Rs 0.068 lakh at 50 tpd, so the biggest kiln gets the cheapest repair for its size.

Printed rupee savings against tonnes times price

• 15 tpd: the body's 48 tonnes x Rs 7,000 = Rs 3.36 lakh (my arithmetic). The summary's 36 tonnes x Rs 7,000 = Rs 2.52 lakh, so its Rs 2.5 lakh ties to 3%, not to 48 tonnes. The text prints Rs 3.0 lakh and Table 3.1 prints Rs 2.5 lakh, which the report uses for payback. An annexure table prints 1,164 tonnes after the work, not 1,152.
• 30 tpd: the body's 100 tonnes x Rs 7,000 = Rs 7.00 lakh (my arithmetic), the top of the larger range, against Rs 5.0 to 6.0 lakh in section 3.2. The summary's 84 x 7,000 = Rs 5.88 lakh, printed as Rs 5.5 lakh.
• 50 tpd: the body's 140 tonnes x Rs 7,000 = Rs 9.80 lakh (my arithmetic), inside the printed Rs 9.0 to 10.0 lakh. The summary prints the same sum as Rs 9.0 lakh, where it should read 9.8. The live page on the 50 tpd case reads it the same way: the summary's Rs 9.0 lakh is a wrong sum, the body's range is 9.0 to 10.0.

Paybacks and indicators that do not tie

• 30 tpd: the text says payback is less than 4 months and Table 4.2 prints 4. Rs 2.4 lakh / Rs 6.0 lakh is 0.4 years, 4.8 months, and at Rs 7.0 lakh it is 4.1 months, so neither end gives under 4.
• 15 tpd: section 4.3.2 prints 0.5 years (1.2 / 2.5 = 0.48 years, 5.8 months) while Table 4.2 prints 3 months. Section 4.3.3 gives net present value (NPV) Rs 5.0 lakh and an internal rate of return (IRR) of 172%; Table 4.2 gives 5.2 and 145%.
• 15 tpd sensitivity (Table 4.3): the base saving is Rs 2.5 lakh, the pessimistic case Rs 3.275 lakh and the optimistic Rs 2.625 lakh, so the pessimistic case is higher than the base.
• 50 tpd: the text says under 6 months and Table 4.2 says 5. At the summary's Rs 9.0 lakh the sum is 3.4 / 9.0 = 4.5 months; at Rs 9.8 lakh it is 4.2 months.

Before you order

• Work out your own pet coke tonnes a year from invoices. If you burn 80 tonnes a year for each tonne a day, the reports' ratio applies to you.
• The saving is a 3 to 4% cut in fuel, so it only shows against a clean baseline. Plan for the downtime too: each report says the kiln is down for about a month, and 4 to 5 weeks in its schedule.
• Re-run the sum at today's pet coke price, not Rs 7,000.

The 30 tpd report with its own tonnes and price

• Pet coke saved: 2,400 minus 2,300 = 100 tonnes. At Rs 7,000 a tonne: Rs 7.00 lakh a year
• Printed: Rs 5.0 to 6.0 lakh in section 3.2, Rs 6.0 to 7.0 lakh in section 4.3
• Cost Rs 2.4 lakh. At Rs 6.0 lakh a year: 2.4 / 6.0 = 0.4 years = 4.8 months. At Rs 7.0 lakh: 4.1 months
• Printed payback: 'less than 4 months' in the text, 4 in Table 4.2

Figures are the report's own, at the report year's prices; the months are my division of its figures.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so the pet coke bought each month is on file to test a report's baseline against. It does not measure kiln surface heat. The green loan check shows what a lender asks for.

• Green loan readiness check
• Lime kiln insulation and pet coke saving (50 tpd case in full)
• Pet coke storage loss at a lime kiln
• Jodhpur lime kiln units and pet coke carbon

Sources: BEE, Detailed project report: kiln insulation improvement, 15 tpd kiln, Jodhpur limestone cluster (SAMEEEKSHA), BEE, Detailed project report: kiln insulation improvement, 30 tpd kiln, Jodhpur limestone cluster (SAMEEEKSHA), BEE, Detailed project report: kiln insulation improvement, 50 tpd kiln, Jodhpur limestone cluster (SAMEEEKSHA)

Last reviewed 2026-11-05. Report figures are from BEE's Small and Medium Enterprises (SME) programme project reports of 2011; costs, pet coke price and paybacks are at the report year's prices. Check today's pet coke price and a current quote before you rely on the payback.