Indian Coal-fired Power Plants Research Articles

The Impact of Electricity Sector Restructuring on Coal-fired Power Plants in India

We examine whether the unbundling of generation from transmission and distribution services at state-owned power plants in India improved operating efficiency at these power plants. Between 1995 and 2009, 85 percent of coal-based generation capacity owned by state governments was unbundled from vertically integrated State Electricity Boards into state generating companies. We find that generating units in states that unbundled before the Electricity Act of 2003 experienced reductions in forced outages of about 25% and improvements in availability of about 10%, with the largest results occurring 3-5 years after unbundling. We find no evidence of improvements in thermal efficiency at state-owned power plants due to unbundling.

Erratum to: Integrating SO2 and NO x control systems in Indian coal-fired power plants

Erratum to: Integrating SO2 and NO x control systems in Indian coal-fired power plants

Integrating SO2 and NO x control systems in Indian coal-fired power plants

Coal-fired power plants are amongst the largest sources of air pollution in India. These power plants emit a number of gaseous pollutants, including sulphur dioxide (SO2), nitrogen oxides (NOx) and also particulate matter. Recent international as well as national studies show a rapid increase in SO2 and NOx emissions. Both these gases have harmful impact on human health and hence need to be controlled. Typically, these pollutants are controlled using the wet flue gas desulphurization (FGD) units (for SO2) and hot-side selective catalytic reduction (SCR) units (for NOx)—mostly absent in the coal-fired power plants in India. This paper attempts to understand the plant level implications of using Wet FGD and hot-side SCR systems in Indian coal-fired power plants. The impacts on the technical (efficiency, energy penalty), environmental (emissions, fuel use) and economic (cost of electricity) aspects have been estimated through simulation of a power plant with and without the emission controls. Effect of increasing use of high-sulphur imported coal has also been discussed.

The Impact of Electricity Sector Restructuring on Coal-Fired Power Plants in India

We examine whether the unbundling of generation from transmission and distribution services at state-owned power plants in India improved operating efficiency at these power plants. Between 1995 and 2009, 85 percent of coal-based generation capacity owned by state governments was unbundled from vertically integrated State Electricity Boards into state generating companies. We find that generating units in states that unbundled before the Electricity Act of 2003 experienced reductions in forced outages of about 25% and improvements in availability of about 10%, with the largest results occurring 3-5 years after unbundling. We find no evidence of improvements in thermal efficiency at state-owned power plants due to unbundling.

Decadal emission estimates of carbon dioxide, sulfur dioxide, and nitric oxide emissions from coal burning in electric power generation plants in India

This study aims to estimate the emissions of carbon dioxide (CO₂), sulfur dioxide (SO₂), and nitric oxide (NO) for coal combustion in thermal power plants in India using plant-specific emission factors during the period of 2001/02 to 2009/10. The mass emission factors have been theoretically calculated using the basic principles of combustion under representative prevailing operating conditions in the plants and fuel composition. The results show that from 2001/02 to 2009/10 period, total CO₂ emissions have increased from 324 to 499 Mt/year; SO₂ emissions have increased from 2,519 to 3,840 kt/year; and NO emissions have increased from 948 to 1,539 kt/year from the Indian coal-fired power plants. National average emissions per unit of electricity from the power plants do not show a noticeable improvement during this period. Emission efficiencies for new plants that use improved technology are found to be better than those of old plants. As per these estimates, the national average of CO₂ emissions per unit of electricity varies between 0.91 and 0.95 kg/kWh while SO₂ and NO emissions vary in the range of 6.9 to 7.3 and 2.8 to 2.9 g/kWh, respectively. Yamunagar plant in Haryana state showed the highest emission efficiencies with CO₂ emissions as 0.58 kg/kWh, SO₂ emissions as 3.87 g/kWh, and NO emissions as 1.78 g/kWh, while the Faridabad plant has the lowest emission efficiencies with CO₂ emissions as 1.5 kg/kWh, SO₂ emissions as 10.56 g/kWh, and NO emissions as 4.85 g/kWh. Emission values at other plants vary between the values of these two plants.

Enrichment and particle size dependence of polonium and other naturally occurring radionuclides in coal ash

Coal fired thermal power contributes 70% of power in India. Coal fired power generation results in huge amounts of fly ash and bottom ash of varying properties. Coal, which contains the naturally occurring radionuclides, on burning results in enrichment of these radionuclides in the ashes. In the present study, coal, bottom ash and fly ash samples collected from six coal-fired power plants in India were measured for 210Po using alpha spectrometry and for natural U, 226Ra, 232Th and 40K by an HPGe γ-ray spectrometer. 210Po in fly ash ranged from 25.7 to 70 Bq/kg with a mean value of 40.5 Bq/kg. The range and mean activities of 238U, 226Ra, 232Th, 40K in fly ash were 38.5–101 (78.1), 60–105.7 (79), 20–125 (61.7) and 43.6–200 (100) Bq/kg respectively. Fly ash and bottom ash contains two to five times more natural radionuclides than feed coal. The results were compared with the available data from earlier studies in other countries. The effect of particle size on enrichment factor of the nuclides in fly ash was studied. 210Po showed the largest size dependence with its concentration favoring the smaller particle size while 232Th showed least size dependence. 238U and 226Ra showed behavior intermediate to that of 210Po and 232Th. Also the correlation between sulfur content of the feed coal and activity of 210Po was investigated. Increased sulfur content in feed coal enhanced enrichment of 210Po in ash.

Why Are Power Plants in India Less Efficient than Power Plants in the United States?

India's coal-fired generating capacity doubled between 1990 and 2010 and currently accounts for 70 percent of electricity produced. Despite this, thermal efficiency at state-owned coal-fired power plants in India is significantly lower than at plants in the United States. When matched on age and capacity, heat input per kWh was 8 percent higher at Indian plants between 1997 and 2009. This can only partly be explained by the lower heat content of Indian coal. Electricity sector restructuring in the United States improved thermal efficiency at investor-owned plants; however, electricity sector restructuring in India has yet to improve thermal efficiency at state-owned coal-fired power plants.

Ozone Monitoring Instrument Observations of Interannual Increases in SO2 Emissions from Indian Coal-Fired Power Plants during 2005–2012

Due to the rapid growth of electricity demand and the absence of regulations, sulfur dioxide (SO2) emissions from coal-fired power plants in India have increased notably in the past decade. In this study, we present the first interannual comparison of SO2 emissions and the satellite SO2 observations from the Ozone Monitoring Instrument (OMI) for Indian coal-fired power plants during the OMI era of 2005-2012. A detailed unit-based inventory is developed for the Indian coal-fired power sector, and results show that its SO2 emissions increased dramatically by 71% during 2005-2012. Using the oversampling technique, yearly high-resolution OMI maps for the whole domain of India are created, and they reveal a continuous increase in SO2 columns over India. Power plant regions with annual SO2 emissions greater than 50 Gg year(-1) produce statistically significant OMI signals, and a high correlation (R = 0.93) is found between SO2 emissions and OMI-observed SO2 burdens. Contrary to the decreasing trend of national mean SO2 concentrations reported by the Indian Government, both the total OMI-observed SO2 and annual average SO2 concentrations in coal-fired power plant regions increased by >60% during 2005-2012, implying the air quality monitoring network needs to be optimized to reflect the true SO2 situation in India.

Effect of addition of pond ash and fly ash on properties of ash—clay burnt bricks

Two industrial solid waste products generated by Indian coal-fired power plants, namely pond ash and fly ash, were used in combination with local clay to develop building bricks. The clay were mixed with the two different ashes in the range 10 to 90 wt.%, hydraulically pressed and fired at 1000 degrees C. The fired products were characterized for various quality properties required for building bricks. The properties of the optimal compositions were compared with conventional red clay bricks including the developed microstructures and the comparative study generally showed that te ash-clay bricks were of superior quality to the conventional products.

Techno-economic evaluation of revamping of coal-fired power plants in India

A techno-economic feasibility study has been conducted to investigate the revamping of two 32 MWe Pulverised-Coal (PC) boilers with a number of firing options. The options investigated were: (1) conventional PC revamping, (2) replacement with a new PC boiler, (3) PC to Circulating Fluidised Bed (CFB) revamping, (4) replacement with a new CFB boiler, and (5) Bubbling Fluidised Bed (BFB) revamping. The study reveals that: (i) CFB revamping of the boilers is technically feasible and economically viable; (ii) Performance improvement of the plant is significant in terms of such indices as plant load factor, forced outage and auxiliary oil consumption; (iii) Significant improvement in emissions performance due to the reduction in emissions of NOx and fly ash is projected; (iv) CFB revamping option gives the highest return on investment compared to alternatives. Finally, to demonstrate the technical soundness and viability of the special design used in this revamping, a subscale CFB boiler has been designed and built at another power plant.

03/02025 Technologically enhanced natural radiation due to coal-fired power plants in India: Ramachandran, T. V. and Mishra, U. C. BfS-SH-Berichte, 2002, 24, 321–327

03/02025 Technologically enhanced natural radiation due to coal-fired power plants in India: Ramachandran, T. V. and Mishra, U. C. BfS-SH-Berichte, 2002, 24, 321–327

Barriers to adopting least-cost particulate control strategies for Indian power plants

Future energy growth in India, fueled in large part by coal, is expected to further aggravate the existing problems of particulate air pollution. This paper evaluates strategies for reducing particulate emissions from new and existing coal-fired power plants in India to comply with current and anticipated future emissions standards. The objectives are to identify methods that minimize total power generation costs, and to identify economic and political barriers to adopting these solutions. The technologies considered include conventional electrostatic precipitators, fabric filter collectors, flue gas conditioning, coal cleaning and switching to imported coal. The results suggest that the most significant savings in particulate control costs are realized through a ‘systems’ approach involving pre-combustion and post-combustion emission control methods. Nationwide savings in generation costs through improved control are estimated at approximately $0.4–0.7 billion per annum in the year 2002 (in constant 1996 dollars). Least-cost strategies are not currently being used because of capital cost subsidies, lack of domestic technology demonstration and evaluation programs, an emphasis on pollution control versus pollution prevention, and an imperfect domestic steam coal market. Policy measures are proposed to overcome these barriers.