Why does the Bureau of Energy Efficiency 200 tonne biomass gasifier report pay back in 0.99 years when the others take 2 to 3?

Six Bureau of Energy Efficiency (BEE) Godavari gasifier reports pay back in 0.99 to 3.21 years. The 200 tonne wood one is quickest: its sheet assumes 60% heat loss, not 55%, moving payback from about 1.7 to 0.99 years, and puts the same rupees (Rs) 28 lakh gasifier on a kiln burning 4,200 tonnes of coal a year, not 2,800.

The six reports

• Biomass (wood), 50 tonne kiln: Rs 17.00 lakh, saves Rs 6.23 lakh a year, payback 2.73 years. Report carbon dioxide (CO2): 2,430 tonnes.
• Biomass, 100 tonne kiln: Rs 34 lakh, Rs 12.50 lakh, 2.72 years. CO2: 5,040 tonnes.
• Biomass, 200 tonne kiln: Rs 37 lakh, Rs 37.50 lakh, 0.99 years. CO2: 7,560 tonnes.
• Coal gasifier, 50 tonne kiln: Rs 36.46 lakh, 269 tonnes of coal saved, Rs 11.37 lakh, 3.21 years. CO2: 2,430 tonnes.
• Coal gasifier, 100 tonne kiln: Rs 62.17 lakh, 666.6 tonnes saved, Rs 28.80 lakh, 2.16 years. CO2: 1,200 tonnes.
• Coal gasifier, 200 tonne kiln: Rs 65.17 lakh, 771.45 tonnes saved, Rs 32.61 lakh, 2.00 years. CO2: 1,388 tonnes.
• All six cost coal at Rs 4,500 a tonne and 4,200 kilocalories (kcal) a kilogram; the wood reports cost wood at Rs 2,500 a tonne and 2,000 kcal a kilogram.

Why the 200 tonne wood report stands out

The 100 and 200 tonne wood reports use the same gasifier, 1,250,000 kcal an hour at Rs 28 lakh. The 100 tonne sheet takes 55% heat loss and a 90% use factor; the 200 tonne sheet takes 60% heat loss and no use factor. Both wood sheets imply 60% gasifier efficiency, since the wood's heat is the gasifier's output divided by 0.6. The 200 tonne sheet saves Rs 2.50 lakh a batch, against Rs 0.63 for the 100 tonne kiln.

At the other sheets' 55% loss the 200 tonne kiln needs 529.2 million kcal a batch and 441 tonnes of wood, and the saving drops to about Rs 1.48 lakh a batch, Rs 22 lakh a year, payback near 1.7 years. So the 60% assumption alone moves payback from about 1.7 to 0.99 years. The rest of the gap to the 100 tonne report's 2.72 years comes from putting the same Rs 28 lakh gasifier on a kiln that burns 4,200 tonnes of coal a year, against 2,800.

Even at 55% that asks a lot of the machine: 529.2 million kcal over the 16 day batch is 33.1 million kcal a day, above the 30 million the gasifier can give in 24 hours. The coal report for the same kiln picks a 2,000,000 kcal an hour gasifier. Its project cost is Rs 65.17 lakh, of which the equipment is Rs 54.55 lakh.

One CO2 figure that is not the saving

In the 50 tonne coal gasifier report the CO2 line is 2,430 tonnes, which is 1,350 tonnes of coal x 1.8, all the coal the kiln burns now. The report saves 269 tonnes, which at 1.8 is about 484 tonnes, and the report's own section 3.4.2 states 484 tonnes of CO2 against the 2,430 in its summary. In the 100 and 200 tonne coal reports the CO2 line matches coal saved x 1.8. For the wood reports the CO2 line is the coal replaced x 1.8; the wood's own CO2 is biogenic, reported separately.

Which figures to rely on

• Coal per batch from your own weighbridge slips, before you pay for anything.
• Gasifier rating checked against kiln heat per day in the rapid firing days.
• A supplier guarantee on kcal output and wood or coal use for your kiln size.
• The wood price and moisture you can really buy; Rs 2,500 a tonne at 2,000 kcal a kilogram is dearer per kcal than coal at Rs 4,500 and 4,200.

The 200 tonne wood report on its own method, then at 55% loss

• As printed: 1,176 million kcal x 40% = 470.4 million kcal; wood 25 tonnes a day x 16 days = 400 tonnes
• Wood Rs 10.00 lakh + power Rs 0.10 lakh against coal Rs 12.60 lakh: saving Rs 2.50 lakh a batch, 15 batches, Rs 37.50 lakh
• At 55% loss: 1,176 x 45% = 529.2 million kcal; at 60% gasifier efficiency that is 882 million kcal of wood, 441 tonnes
• Wood Rs 11.03 lakh + Rs 0.10 lakh: saving Rs 1.48 lakh a batch, Rs 22.1 lakh a year; Rs 37 lakh / 22.1 = 1.7 years

Report figures except the 55% line, which applies the other reports' loss to this report's own inputs.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so the fuel bought before a gasifier goes in is on file to compare against. The green loan check shows what a lender asks for.

• Green loan readiness check
• Coal gasifier on a 100 tonne downdraft kiln
• Wood gasifier on a refractory kiln: CO2
• Heat recovery on a 200 tonne kiln: is the CO2 right

Sources: BEE, Detailed project report: biomass gasifier, kiln up to 50 tonnes, Godavari refractories (SAMEEEKSHA), BEE, Detailed project report: biomass gasifier, kiln up to 100 tonnes, Godavari refractories (SAMEEEKSHA), BEE, Detailed project report: biomass gasifier, kiln up to 200 tonnes, Godavari refractories (SAMEEEKSHA), BEE, Detailed project report: coal gasifier, 50 tonne kiln, Godavari refractories (SAMEEEKSHA), BEE, Detailed project report: coal gasifier, 200 tonne kiln, Godavari refractories (SAMEEEKSHA)

Last reviewed 2026-11-04. Report figures are from BEE's Small and Medium Enterprises (SME) programme project reports; costs, tariffs and paybacks are at the report year's prices. Check today's prices and a current quote before you rely on the payback.