The Howrah galvanizing and wire drawing manual says the cluster could save rupees (Rs) 112,968,944 a year, but its table adds to more. Why?

The table adds to Rs 119,028,280 for 101 units; the text says 112,968,944. The text matches measures 1 to 14 only, leaving out measures 15 and 16 (direct wired drawing machines, and a direct current to alternating current drive), Rs 1,076,676 across 15 units, and scales by 101 over 15, not 100. My reading; the manual does not explain.

The two totals

• Text, under Table 6.3: the measures in the 15 audited units save Rs 16,777,566 a year, "around 22% of total energy consumption", out of an energy cost of Rs 74,951,492. For the 101 galvanizing and wire drawing units, "the estimated total saving potential" is Rs 112,968,944.
• Techno-economic table in section 6.2: 16 measures. Each shows a saving per unit, how many of 15 units may adopt it, how many of 101, and a total saving potential. That last column adds to Rs 119,028,280.
• The difference is Rs 6,059,336.

Where the difference comes from

1. The 15-unit figure. Multiply each measure's saving per unit by the number of the 15 units that may adopt it. Measures 1 to 14 give Rs 16,777,575, within Rs 9 of the printed 16,777,566. Measures 15 and 16, direct wired drawing machines (Rs 672,295, one unit) and a direct current drive to an alternating current drive with a variable frequency drive (Rs 404,381, one unit), add Rs 1,076,676. All 16 give Rs 17,854,251.
2. The scaling. The table's totals use 100 over 15: 16,777,566 x 100 / 15 = 111,850,440, which is exactly the table's total for measures 1 to 14. The text uses 101 over 15: 16,777,566 x 101 / 15 = 112,968,944.
3. Put together: table total 119,028,280 = 111,850,440 + 4,481,967 + 2,695,873, the last two being the totals for measures 15 and 16. The text figure is 1,118,504 above the first part and leaves the other two out. 119,028,280 less 112,968,944 is 6,059,336, which is 7,177,840 less 1,118,504.

Which to quote

• Rs 119,028,280 (Rs 11.90 crore) covers every measure at the table's scale. Rs 112,968,944 (Rs 11.30 crore) matches measures 1 to 14 and leaves out measures 15 and 16 (direct wired drawing machines, and a direct current to alternating current drive), by my reading. One crore is 10 million.
• Neither is a measurement of the cluster. The manual says its figures come from the identified units' calculations, "averaged to represent the Howrah Cluster", and it states that production capacity varies more than ten fold. Unit sizes among the 15 run from 241 to 7,500 tonnes a year.
• The 22% holds for measures 1 to 14: 16,777,566 / 74,951,492 = 22.4%. With all 16 it is 17,854,251 / 74,951,492 = 23.8%.
• The text lists savings of kilowatt hours (kWh), wood, liquefied petroleum gas and furnace oil, and no coal. The manual's carbon dioxide table shows coal as 992 of the 2,525 tonnes saved, so the sentence is not a full list.

One row, to show the scale

• Measure 7, better furnace insulation: saving Rs 487,632 a unit, cost Rs 34,060, payback 34,060 / 487,632 = 0.07 years
• 6 of the 15 audited units may adopt it, so about 6 x 100 / 15 = 40 of 101
• Total saving potential: 487,632 x 40 = Rs 19,505,280, printed as Rs 19,505,273

All figures are the manual's own, from an undated manual of about 2010 to 2011 (its references were read in 2010), at older prices and fuel costs. The per-unit saving is an average, not your plant.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so your own fuel and power use is on file to compare with a measure's printed saving. The manual's figures are averages for 15 units, not a quote for your plant.

• Howrah galvanizing and wire: fuel and Carbon Border Adjustment Mechanism (CBAM)
• Galvanizing furnace insulation: oil saving
• Wire drawing: direct current to alternating current drive
• Galvanizing plant energy per tonne
• Green loan readiness check

Sources: Bureau of Energy Efficiency (BEE), Manual on energy conservation measures in the galvanizing and wire drawing sector, Howrah cluster (SAMEEEKSHA)

Last reviewed 2026-11-05. Figures are from an undated manual of about 2010 to 2011. The explanation of the Rs 6,059,336 gap is my arithmetic and matches to within Rs 9 on the 15-unit figure and exactly on the table; the manual does not explain it. Use today's fuel prices before relying on any saving.