Indian Power-plant NO x Emissions from OMI and Inventories David Streets and Zifeng Lu Argonne National Laboratory Argonne, IL AQAST-3 Meeting University of Wisconsin - Madison June 13-15, 2012

A new, multi-year, bottom-up inventory of NO x emissions from Indian power plants has been developed A detailed, unit-level inventory has been developed for India’s power sector during –All units with capacity larger than 20 MW (> 800 units) are included –Plant-wise fuel consumption Data source: Thermal Performance Review ( ); CEA, Government of India NO x emission factors (g/GJ) NO x control assumptions –Coal-fired power plants: S1: Default IPCC EF is applied to all units S2: No unit with LNB S3: Units with capacity > 300 MW with LNB S4: Units with capacity > 100 MW with LNB S5: Units built after 1996 are equipped with LNB –Other thermal power plants: India has NO x emission standards for gas-, liquid-, and diesel-fired power plants 2 All (not classified)<100 MW100–300 MW> 300 MW w/o LNB300 b 308 a 330 a 410 b w/ LNB300 b 177 c 188 d 236 a,d a Zhao et al., 2008 b IPCC, 2006 c Estimated d Zhao et al., 2010

Increasing trend in Indian NO x power plant emissions 3 From 1996 to 2010, Indian thermal power plants showed: Generating capacity:84% increase Electricity generation:110% increase Coal consumption:95% increase NO x emissions:71 ‒ 103% increase (S1-S5)

Indian power plants locations vs. NO 2 columns 4 Graphic shows the spatial distribution of monthly mean tropospheric NO 2 from OMI during March 2005 – February Data source: KNMI, DOMINO ver. 2.0, Level 3

Seasonal response is highly variable 5 Due to frequent cloud cover and heavy monsoon rainfall, July to September is the worst period for India to observe NO 2 from satellites, thus excluded from the analysis.

Interannual variation of “power-plant” NO 2 columns 6  Indian power plants are aggregated to 81 areas ⁰ × ⁰ for an area with a single plant  For area i, NO 2 tropospheric column due to emissions from power plant is calculated by: [NO 2 ] power, i = (Emi power, i ÷ Emi i )× [NO 2 ] i Emi i are total NO x emissions in area i Area emissions are taken from EDGAR4.1 for 2005, and scaled to based on the GAINS inventory

Satellite NO 2 trends for power plants are in good agreement with bottom-up NO x inventory emission trends 7 We find that the ratio of ∆E/E to ∆TVCD/TVCD decreased to less than one around 2005−2008, implying that increasing the same proportion of NO x emissions leads to a greater surface NO 2 increase now than in the past (NO x pollution in India becomes more and more serious) a transition of the overall NO x chemistry occurred over the power plant areas, which may cause significant impact on the atmospheric environment

Comparisons of NO x emissions vs. NO 2 columns 8 Scatter plots (top, middle) R 2 vs. the fraction of power emissions in the grid cell (f power )

Situation for India seems better than for China Similarity NO x emissions from power sector are high and are continuously increasing in both countries Differences The latitude of India is lower than China. Therefore, in India, –temperature is higher; NO 2 lifetime is shorter; observed NO 2 columns are more closely correlated with NO x emissions –solar zenith angle is smaller, and thus the tropospheric NO 2 retrievals are more reliable (the vertical profile sensitivity of the satellite measurement is a function of solar zenith angle at the time of satellite overpass) –seasonality is weaker. All-year data (except for monsoon) can be used, whereas only summer data are used for China Area emissions are smaller in India than in China –Indian NO 2 columns are distributed as individual hotspots which are good for quantitative analysis 9

Current status Paper entitled, “Increase in NOx emissions from Indian thermal power plants during : unit-based inventories and multi-satellite observations,” has been submitted to Environmental Science & Technology. Reviews have been received and are OK. Revised paper to be submitted by June 19. We intend to inter-compare our analyses for China and India and add in Southeast Asia (in collaboration with the NASA SEAC4RS mission). Implications for the U.S. to follow. 10