Air Pollution Control in India: Getting the Prices Right

1. Air Pollution Control in India: Getting the Prices Right Maureen Cropper, Shama Gamkhar, Kabir Malik, Alex Limonov and Ian Partridge

2. Goals of This Paper • Estimate health damages of SO2, NOx, PM emissions from coal-fired power plants in India • Calculate damages per plant based on 2008 emissions • Calculate damages per ton of SO2, NOx, PM2.5 for each plant • Use results to estimate benefits of two pollution control measures: • Coal washing (to reduce ash content of coal) • Flue-gas desulfurization units (scrubbers)

3. Motivation for the Paper • Is current emphasis on controlling directly emitted PM misplaced? • Pollution permit markets in Tamil Nadu, Gujarat focus on PM • Should there be controls on SO2 emissions? • India currently has no limits on SO2 emissions from power plants, possibly because of low S content (0.5%) • But, kg coal/kWh are high due to low heating value of coal and exposed population is large • Domestic coal has high ash content (30-50%) but only 5% of coal is washed • What are the health benefits of coal washing?

4. Our Approach • Assemble database on 92 coal-fired power plants, 1994-2008 • Plants constituted 88% of installed coal capacity in 2008 • Calculate emissions of SPM (63 plants), SO2, NOx (68 plants) for 2008 • Predict change in population-weighted ambient concentrations of fine particles per ton of PM2.5, SO2, NOx emitted • Using gridded population data around each plant • Use Pope et al. (2002) study to predict premature mortality from cardiopulmonary causes for adults ≥ 30

5. Main Results • About 75% of deaths are due to SO2; about 20% to NOx; 5% to directly emitted PM • Ash content is high, but ESPs are used by all plants • Variation across plants in deaths per ton of pollutant is small: • Mean deaths per 1,000 tons of SO2 = 10 (s.d. = 2) • Coal washing reduces deaths from Rihand plant by 20% - most due to reduction in SO2 • Cost per life saved of scrubber at Dahanu plant = Rs. 3.55 million; 123 lives saved per year

6. Coal-Fired Power Plants in India • Generate about 70% of electricity in India • Coal burned per kWh 60% greater than in US • Coal/kWh ≡ (Heating value of coal)/(OPHR of plant) • Heating value of coal (3625 kcal/kg) much lower than in the US (4400-7000 kcal/kg) • OPHR (kcal/kWh) of plants higher than in US due to high ash content of coal and operating inefficiencies • Ash content of coal = 30-50% (cf. 4-5% for PRB coal) • Sulfur content = 0.5% by weight (PRB coal ≈0.4% Illinois coal = 3-4%)

7. Pollution Regulations and Control Equipment Used • Emissions standards for TSP (SPM) are concentration standards • Violated by about 25% of plants for which data are available • Ash content of coal must be ≤ 34% in sensitive and critically polluted areas • All power plants have ESPs, although ash content affects their efficiency • No limits on SO2 emissions, but • Minimum stack height requirements • Plants (EGUs) over 500 MW must leave space for a scrubber • No limits on NOx emissions, but most plants have low-NOx burners

8. Pollution Intensity of Coal-Fired Power Plants: India v. US (Lbs/MWh)

9. Estimating the Impact of Emissions on Ambient Air Quality • Need to translate emissions into ambient air quality for each plant • Applying a Gaussian dispersion model (e.g., CALPUFF) to 90 plants beyond the scope of the project • Zhou et al. (2006) ran CALPUFF for 29 identical power plants in China, in different locations • Change in population-weighted ambient concentration of sulfates per ton of SO2 emitted related to population in concentric annuli around each plant and annual precipitation • These equations used to predict the change in population-weighted ambient concentrations at each plant, based on gridded population data and precipitation data for India

10. Legend Coal based power plant ! ( Population (2005) Up to 10,00,000 10,00,001 - 25,00,000 25,00,001 - 50,00,000 50,00,001 - 75,00,000 More than 750000 Population covered within 100km radius from the power plants Population covered within 100km radius from power plants

11. Estimating Health Effects • Only a few time series, no cohort studies linking air pollution to mortality in India • Time series studies find similar magnitudes of effects of PM on mortality as NMMAPS (US) and APHEA (EU) studies in spite of higher ambient concentrations in India • We transfer results from Pope et al. (2002) for cardiopulmonary mortality • Estimates capture impacts of fine particles on deaths over 30; no impacts on under-30 mortality or morbidity

12. Distribution of Deaths per Plant, by Pollutant

13. Legend Coal based power plant ! ( Population (2005) Up to 10,00,000 10,00,001 - 25,00,000 25,00,001 - 50,00,000 50,00,001 - 75,00,000 More than 750000 Location of coal-based power plants Rihand Dahanu

14. Coal Washing at Rihand Plant • Assume coal-washing reduces ash content from 43% to 35% • This also reduces S content from 0.39% to 0.34% • By raising heating value of coal, reduces amount of coal used by 14% • Coal washing raises cost of electricity generation by 16%

15. Health Benefits of Coal Washing

16. Cost per Life Saved of FGD • Dahanu 500 MW plant has a seawater FGD • Raises cost of electricity by 9% • Estimated removal efficiency = 80% • Estimated 123 lives saved annually • Cost per life saved = $3.55 million Rs. • Cost of FGD would be higher using conventional FGD • But most plants have higher damages per ton SO2

17. Conclusions & Caveats • Damages estimates are preliminary—need to refine atmospheric chemistry • Benefits of controlling SO2 are clear • Whether require scrubbers or use a permit market depends on differences in costs of control across sources • Differences in pollution damages per ton SO2 across plants small • Significant health benefits of coal washing