Which fuel was cheapest for each unit of heat in Morbi in 2009, gas, lignite, coal or briquette, and does that still hold for me?

In the Morbi manual's 2009 price table, lignite cost about rupees (Rs) 429 for each million kilocalories of heat, Indonesian coal Rs 491, briquette Rs 875, charcoal Rs 1,231 and piped gas Rs 1,591 to 1,932. Gas cost about 3.7 to 4.5 times lignite for the same heat.

What the manual printed

The Bureau of Energy Efficiency (BEE) Morbi manual lists each fuel's price and its heat content. Prices are for July to December 2009. A kilocalorie (kcal) is a small unit of heat, the way a kilowatt hour measures electricity. A fuel with more kilocalories in each kilogram gives more heat for the same weight, so price alone does not compare fuels.

The table, then the cost of heat

• Piped natural gas: Rs 14 to 17 for each standard cubic metre (scm), 8,800 kcal each.
• Lignite: Rs 1.5 a kilogram, 3,500 kcal.
• Sawdust: Rs 1.5 a kilogram, 4,801 kcal.
• Indonesian coal: Rs 2.7 a kilogram, 5,500 kcal.
• Biomass briquette: Rs 3.5 a kilogram, 4,000 kcal.
• Charcoal: Rs 8 a kilogram, 6,500 kcal.
• Electricity: Rs 4.92 to 5.84 a kilowatt hour (not compared here, since it is not burnt for heat). Diesel, Rs 35 a litre, is left out because its heat is printed per kilogram.
• Cost of a million kcal, price divided by kcal in each unit, times 1,000,000:
• Sawdust: Rs 312 a million kcal
• Lignite: Rs 429 a million kcal
• Indonesian coal: Rs 491 a million kcal
• Biomass briquette: Rs 875 a million kcal
• Charcoal: Rs 1,231 a million kcal
• Piped natural gas: Rs 1,591 to 1,932 a million kcal

What the sums say

Gas cost 3.7 to 4.5 times lignite for the same heat, and 1.8 to 2.2 times briquette. Briquette cost 2.04 times lignite. That is the spread behind the manual's line that solid fuels are cheaper than gas, and behind its project for a briquette hot air generator, which moves part of the heat load from gas to a cheaper solid fuel.

The manual also notes that gas fell from Rs 23 to Rs 15 an scm over a few years, and that some units moved spray dryers from solid fuel to gas for quality reasons. So price per heat was never the whole choice.

What the sums leave out

• Efficiency. A gasifier or hot gas generator loses some heat turning solid fuel into hot gas, and how much depends on the equipment and how it is run.
• Product quality, which the manual names as a reason for the move to gas, and ash, handling and storage, which are my additions.
• Today's prices. These are 2009 prices, so redo the sum with your own invoices.

The catch for carbon dioxide

Cheaper coal carries more carbon dioxide for the same heat. Rough sum, mine and not the manual's: on Intergovernmental Panel on Climate Change (IPCC) default factors, coal gives about 94.6 kg of carbon dioxide for each gigajoule of heat and piped gas 56.1, so coal carries about 1.7 times the carbon dioxide for the same heat (about 396 kg against 235 kg for a million kcal). Treat the ratio as a rough guide. A buyer asking for carbon will see the difference even where the price favours coal.

Do it with your own invoice, example numbers

• A fuel bought at Rs 6 a kilogram, with 5,000 kcal a kilogram printed on the supplier's sheet (an example)
• Rs 6 / 5,000 kcal x 1,000,000 = Rs 1,200 for a million kcal
• Gas at Rs 40 a scm (an example) with 8,800 kcal: 40 / 8,800 x 1,000,000 = Rs 4,545 for a million kcal

Both prices are examples. Use the price and heat value on your own bills, and the same month for both.

What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, so a unit's own gas, oil and power lines are on file to set beside the report's figures. It does not measure a kiln or replace an audit.

• Morbi coal gas against piped gas kiln carbon dioxide
• Morbi energy table: ignore the total row
• Morbi cluster energy and carbon
• Green loan readiness check

Sources: BEE, Manual on Energy Conservation Measures in Ceramic Industry, Morbi cluster (SAMEEEKSHA), IPCC, 2006 Guidelines for National Greenhouse Gas Inventories, Volume 2 Energy

Last reviewed 2026-11-07. Prices and heat values are from the April 2010 BEE Morbi manual, table 6, reference period July to December 2009. Prices have moved a lot since; do not use them for a decision today.