# Why do the Bureau of Energy Efficiency 2 megawatt and 4 megawatt sponge iron waste heat power reports show the same flue gas heat?

Canonical: https://senseible.earth/answers/sponge-iron-waste-heat-power-2-and-4-megawatt-reports

Both Bureau of Energy Efficiency (BEE) Odisha reports list the same flue gas heat, 15.65 million kilocalories (kcal) an hour, and the same 22,561 kilograms of steam an hour. One turns it into 2 megawatts (MW), the other into 4. The reports do not show that step, so ask a supplier for it.

## What the two reports print

- 2 MW report: rupees (Rs) 725 lakh, 14,256,000 kilowatt hours (kWh) a year to the grid, Rs 499 lakh a year, payback 18 months.
- 4 MW report: Rs 960.75 lakh, 28,512,000 kWh a year, Rs 940.90 lakh a year, payback 12 months.
- Same heat sheet in both: two rotary kilns of 100 tonnes a day each (200 in all), 48,000 normal cubic metres of flue gas an hour, 62,400 kilograms an hour at 1,005 degrees Celsius, 15,653,040 kcal an hour available, 15,183,449 after 1% radiation and 2% blowdown losses, and 22,561 kilograms of steam an hour at 66 kilograms per square centimetre and 485 degrees.
- Power: 48,000 kWh a day for the 2 MW plant and 96,000 for the 4 MW, with 10% used by the plant itself, 330 working days a year.

## Where the reports part ways

Row 28 of each heat sheet gives power from that steam: 2 MW in one, 4 MW in the other. Neither shows the steam to power sum. The 4 MW report's turbine table also rates the turbine at 4 MW but lists the maximum power generated as 2 MW, and both reports list the same 18 tonnes an hour of turbine inlet steam. Both heat sheets cover 200 tonnes a day although the first report is titled for 100, and the 4 MW report's page headers still read 2 MW. In both, the boiler makes 22,561 kilograms of steam an hour, about 22.5 tonnes, while the turbine takes 18.

The reports do not say why the same steam gives twice the power. Before you read either figure as a forecast, ask the turbine maker for kilowatts at your kiln's actual flue gas flow and temperature.

## The money rows

The 499 and 998 lakh in the benefit tables are the units times Rs 3.50 a kWh (14,256,000 x 3.50 = 498.96 and 28,512,000 x 3.50 = 997.92), but the same tables print Rs 3.30 a kWh. At Rs 3.30 the figures are Rs 470 lakh and Rs 940.9 lakh. The 4 MW summary uses 940.90, the Rs 3.30 figure.

Cost and payback also vary inside each report. The 2 MW plant is Rs 725 lakh in the summary, Rs 625 lakh in annexure 2 and Rs 746.03 lakh in the financial annexure; its payback is 18 months in the summary and 1.36 years in annexure 2, which adds operation and manpower cost. The 4 MW report gives 12 months and 1.03 years the same way.

## What to carry into a loan file

- Gross kilowatts the turbine will make from your own flue gas, in writing.
- Your own tariff and whether the power displaces grid units or captive coal power.
- The total cost with civil work and taxes, from a current quote.
- Meter readings of generation and the plant's own use after commissioning.

## Grid units displaced, in carbon dioxide (estimate)

- 2 MW report: 14,256,000 kWh x 0.675 = 9,623 tonnes of carbon dioxide (CO2) a year
- 4 MW report: 28,512,000 kWh x 0.675 = 19,246 tonnes
- Neither report gives a CO2 figure; it only says the plant will reduce coal use and emissions

Only if the units replace grid power. Grid factor is the Central Electricity Authority (CEA) financial year 2025-26 figure, an estimate.

## What Senseible does here

Senseible reads electricity bills and fuel invoices into monthly records, so grid units bought before and after a waste heat plant can be compared month by month. Generation from your own turbine meter is a figure you add.

- [Green loan readiness check](https://senseible.earth/green-loan-check)
- [Waste heat power at a sponge iron plant: what to count](https://senseible.earth/answers/barbil-sponge-iron-plant-waste-heat-power)
- [Sponge iron kiln fuel economiser](https://senseible.earth/answers/sponge-iron-kiln-fuel-economizer-coal-saving)
- [Raw material preheating at a sponge iron kiln](https://senseible.earth/answers/odisha-sponge-iron-raw-material-preheating-coal)

Sources: [BEE, Detailed project report: waste heat recovery power plant 2 MW, 100 tonnes a day, Odisha sponge iron (SAMEEEKSHA)](https://sameeeksha.org/pdf/dpr/Orissa_sponge_iron_cluster/Waste_heat_recovery_power_plant_2mw_100tpd_Orissa.pdf), [BEE, Detailed project report: waste heat recovery power plant 4 MW, 200 tonnes a day, Odisha sponge iron (SAMEEEKSHA)](https://sameeeksha.org/pdf/dpr/Orissa_sponge_iron_cluster/Waste_heat_recovery_power_plant_4mw_200tpd_Orissa.pdf), [CEA, CO2 Baseline Database for the Indian Power Sector](https://cea.nic.in/cdm-co2-baseline-view?mappingId=234&lang=en)

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.