# What do the numbers look like for gas turbine cogeneration in a ceramic plant?

Canonical: https://senseible.earth/answers/ceramic-gas-turbine-cogeneration-numbers

BEE's Morbi report sizes two gas engines, 2.72 MW, for a vitrified tile plant: 4.08 million scm of gas a year makes 16.7 GWh, and engine heat replaces 1.64 million scm in the spray dryer. Net CO2 falls about 6,260 t a year. Cost Rs 899 lakh, payback 2.75 years (2010).

## How the plant is set up

- Two engines of about 1.36 MW each carry the whole plant load of 2,109 kW, 24 hours a day for 330 days.
- Of the gas heat, about 40% becomes power, 30% leaves as exhaust that goes straight into the spray dryer, and 20% goes to jacket cooling water, a tenth of which is used to preheat air.
- The engines burn 515 scm an hour. Exhaust replaces 155 scm an hour of dryer gas and jacket heat another 52.
- The spray dryer needs flue gas at about 550 C and is a plant's largest heat user, so it can take the exhaust without extra fuel.

## The money, at 2010 prices

- Grid power avoided: 16,695,360 kWh at Rs 4.15 = Rs 692.85 lakh.
- Dryer gas saved: 1,639,440 scm at Rs 15 = Rs 246 lakh.
- Engine gas bought: 4,080,914 scm at Rs 15 = Rs 612.13 lakh.
- Net: Rs 326.64 lakh a year on Rs 899.11 lakh, so 2.75 years.
- Cost includes Rs 494 lakh engines, Rs 105.22 lakh import duty, Rs 80 lakh heat recovery ducting and Rs 50 lakh civil work. Ten days of dryer downtime.

## Ignore the cover table

The report's summary table shows Rs 1,904 lakh, 11.88 million scm, 23.06 GWh, 9.02 million scm saved and a 3.6 year payback. Its own workings do not produce any of those numbers; the figures above follow the workings. It also says turbine in places, but the equipment priced is gas engines.

## What changes in your carbon figures

- Scope 2 from the grid falls to almost nothing; Scope 1 from gas rises by about 8,370 t.
- Each kWh from the engines carries about 0.50 kg CO2, or about 0.30 kg once the dryer gas it replaces is credited, against 0.675 kg from the grid.
- Gas engines also release a little unburnt methane, which a full inventory should include.
- The case rests on the gas to power price ratio; redo it with today's gas and tariff before you order anything.

## One plant, one year

- Grid avoided: 16,695,360 kWh x 0.675 = 11,269 t
- Dryer gas saved: 1,639,440 scm x 2.05 = 3,361 t
- Engine gas burnt: 4,080,914 scm x 2.05 = 8,366 t
- Net cut: 11,269 + 3,361, less 8,366 = about 6,264 t
- The report says 7,405 t, using older grid factors

Natural gas at our factor of 2.05 kg CO2 a scm and grid at CEA's FY 2025-26 factor, both estimates.

## What Senseible does here

Senseible reads gas bills and electricity bills into monthly records with CO2, so the move from Scope 2 to Scope 1 after cogeneration shows month by month. The green loan check shows what a lender asks for on a project this size.

- [Green loan readiness check](https://senseible.earth/green-loan-check)
- [Splitting CHP emissions: power and steam](https://senseible.earth/answers/chp-emissions-allocation-electricity-and-steam)
- [Gas engine cogeneration methane slip](https://senseible.earth/answers/natural-gas-engine-cogen-methane-slip)
- [Ceramic spray dryer CO2 per tonne](https://senseible.earth/answers/ceramic-spray-dryer-co2-per-tonne-powder)

Sources: [BEE, Detailed project report: gas engine based co-generation technology, 2.72 MW, Morbi ceramic cluster (2010, SAMEEEKSHA)](https://sameeeksha.org/pdf/dpr/MRV_CRM8.pdf), [CEA CO2 Baseline Database, version 22.0](https://cea.nic.in/cdm-co2-baseline-view?mappingId=234&lang=en)

Last reviewed 2026-10-31. Report figures are from a BEE SME programme project report at 2010 prices, when gas cost Rs 15 a scm. Gas and power prices have changed a lot; redo the payback with current prices and a current quote.